Breast Cancer

Although rates are generally low, interstitial lung disease (ILD) can occur at any point in the first year of treatment with trastuzumab deruxtecan (T-DXd) for HER2-positive metastatic breast cancer (MBC).

That’s according to a pooled analysis of three early clinical trials with the drug that was reported at the European Society for Medical Oncology (ESMO): Breast Cancer virtual meeting.

Over a 5-year analysis period, the rate of any grade of ILD was 15.5%. The majority (79%) of those events were grade 1 or 2, observed pulmonologist Charles A. Powell, MD, of Icahn School of Medicine at Mount Sinai in New York, who presented the findings.

Of the 245 patients who were included in the analysis, 38 had an ILD event deemed related to treatment. A respective 9 (3.7%) and 21 (8.6%) had events graded as 1 or 2, 1 patient each (0.4%) had a grade 3 or 4 event, and 6 (2.4%) patients had a grade 5 event.

The timing of the first identified ILD event varied from 1.1 months to 20.8 months, given a median of 5.6 months overall. “This highlights an opportunity for more timely detection of ILD,” Dr. Powell suggested. He added that in almost all (97%) cases, ILD occurred before 12 months and the risk may even decrease over time “suggesting that the risk is not cumulative.”

He cautioned, however: “It is important to note that this analysis is exploratory and hypothesis generating in nature.”
 

ILD occurs with other cancer drugs

ILD is not just associated with T-DXd treatment, said the invited discussant for the trial, Harold J. Burstein, MD, PhD, of the Dana-Farber Cancer Institute in Boston.

“It’s important for clinicians to remember that ILD/pneumonitis is an uncommon, but potentially very serious side effect that affects many breast cancer treatments,” he said.

That not only includes T-DXd, but other newer drugs such the cyclin dependent kinase (CDK) 4/6 inhibitors and immune checkpoint inhibitors, as well as other older more established drugs including taxanes, cyclophosphamide and even the mTOR inhibitor everolimus.

“Both clinicians and patients need to be aware of this risk. It’s part of the differential diagnosis for any patient who develops either ground glass changes or other infiltrates on a CT scan, or who has symptoms,” Dr. Burstein added.
 

Investigating ILD in T-DXd trials

T-DXd (Enhertu) is an anti-HER2-antibody drug conjugate that contains a humanized anti-HER2 IgG1 monoclonal antibody akin to trastuzumab that is linked to DXd, a topoisomerase I inhibitor that is a derivative of exatecan.

It has been approved for use in patients with HER2-positive metastatic breast cancer after two other HER2 treatments fail in the United States and Europe, and after chemotherapy in Japan, noted Dr. Powell. This is largely due to the results from the phase 2, open-label DESTINY-Breast01 trial.

“In breast cancer, T-DXd continues to demonstrate clinically meaningful efficacy with a median duration of response of more than 20 months in a heavily pretreated population,” he said. Objective response rates seen in the DESTINY-Breast01 trial were around 60%, and the median progression-free survival was a little over 19 months.

To look at the issue of drug-related ILD events in patients treated with T-DXd for HER2-positive MBC, an independent adjudication committee was formed to look at all the imaging and clinical data from the DESTINY-Breast01 trial and two single-arm phase 1 trials (NCT02564900 and NCT03383692).

In all, data on 245 patients who had been treated with T-DXd at the approved dose of 5.4 mg/kg in those trials between August 2015 and June 2020 were analyzed.
 

Dealing with lung toxicity

“We are getting new drugs to improve the treatment of cancer, but they always come with a price in terms of toxicity,” observed David Cameron, MD, professor of medical oncology at Edinburgh University in Scotland. Dr. Cameron chaired the session.

“Several measures were taken to identify and mitigate ILD,” across all the T-DXd studies, Dr. Powell explained. As well as the independent adjudication committee, available guidelines were followed and updated on how to diagnose and treat drug-induced lung injuries, and a “safe use” campaign was run in 2019.

Many patients in the early MBC studies were recruited before these measures were in place, such as the use of systemic steroids to manage low-grade events.

The bottom line, however, is that if a patient develops ILD then treatment should be stopped, Dr. Powell said. “Patients with grade 1 events may restart once the ILD has resolved, but those with grade 2 to 4 events must discontinue treatment.”

Dr. Powell concluded: “The overall clinical data support the positive risk-benefit profile of T-DXd. Phase 3 randomized controlled trials in breast cancer are ongoing.”
 

ILD also seen in monarchE trial with abemaciclib

Data on ILD events seen in the phase 3 monarchE trial were also reported separately at the ESMO Breast Cancer virtual meeting. The analysis population included 2,971 patients who had been treated with the CDK 4/6 inhibitor abemaciclib (Verzenio) together with endocrine therapy and 2,800 who had received endocrine therapy alone in the early-stage, adjuvant advanced breast cancer setting.

Most ILD (97%) events that occurred were single occurrences, with any grade of ILD occurring in a higher percentage of patients treated with abemaciclib with endocrine therapy than endocrine therapy alone (2.9% vs. 1.2%). Grade 3 events occurred in a respective 0.4% and 0.0% of patients.
 

So who’s at risk?

The risk factors for ILD and pneumonitis are not well characterized with either of the two drugs discussed, Dr. Burstein observed.

“In the abemaciclib experience, it looked like obesity might be a predisposing factor, with trastuzumab deruxtecan, it looked like patients of Asian ancestry were greater risk, but we need more data to really understand who’s at jeopardy.”

Dr. Burstein observed: “This is something patients need to be aware of as they’re contemplating this treatment.”

While data to prove the benefit of the drug need to mature, Dr. Burstein “would likely discontinue therapy” if a patient were to develop ILD or pneumonitis and treat accordingly.

As for T-DXd, he said: “It’s important that patients know that lung disease is a potentially severe side effect of treatment and that any respiratory symptoms need to be jumped on quickly.”

While prospective studies are now needed, and the phase 3 data should help to better understand the risk of ILD with T-DXd, Dr. Burstein believes it will be important to develop algorithms to ensure the safe administration of the drug.

These algorithms should include “appropriate surveillance and monitoring, especially as we think about trying to move this drug forward into the early stage setting where we’re using it in women who have favorable prognosis, and potentially curative situations for breast cancer.”

The trastuzumab deruxtecan trials were cosponsored by Daiichi Sankyo and AstraZeneca. The monarchE trial was supported by Eli Lilly.

Dr. Powell acknowledged receiving personal fees for acting as an advisory or consultant to both companies as well as to Voluntis. Dr. Burstein had nothing to disclose, and Dr. Cameron had no relevant financial interests in the data being presented.

Although rates are generally low, interstitial lung disease (ILD) can occur at any point in the first year of treatment with trastuzumab deruxtecan (T-DXd) for HER2-positive metastatic breast cancer (MBC).

That’s according to a pooled analysis of three early clinical trials with the drug that was reported at the European Society for Medical Oncology (ESMO): Breast Cancer virtual meeting.

Over a 5-year analysis period, the rate of any grade of ILD was 15.5%. The majority (79%) of those events were grade 1 or 2, observed pulmonologist Charles A. Powell, MD, of Icahn School of Medicine at Mount Sinai in New York, who presented the findings.

Of the 245 patients who were included in the analysis, 38 had an ILD event deemed related to treatment. A respective 9 (3.7%) and 21 (8.6%) had events graded as 1 or 2, 1 patient each (0.4%) had a grade 3 or 4 event, and 6 (2.4%) patients had a grade 5 event.

The timing of the first identified ILD event varied from 1.1 months to 20.8 months, given a median of 5.6 months overall. “This highlights an opportunity for more timely detection of ILD,” Dr. Powell suggested. He added that in almost all (97%) cases, ILD occurred before 12 months and the risk may even decrease over time “suggesting that the risk is not cumulative.”

He cautioned, however: “It is important to note that this analysis is exploratory and hypothesis generating in nature.”
 

ILD occurs with other cancer drugs

ILD is not just associated with T-DXd treatment, said the invited discussant for the trial, Harold J. Burstein, MD, PhD, of the Dana-Farber Cancer Institute in Boston.

“It’s important for clinicians to remember that ILD/pneumonitis is an uncommon, but potentially very serious side effect that affects many breast cancer treatments,” he said.

That not only includes T-DXd, but other newer drugs such the cyclin dependent kinase (CDK) 4/6 inhibitors and immune checkpoint inhibitors, as well as other older more established drugs including taxanes, cyclophosphamide and even the mTOR inhibitor everolimus.

“Both clinicians and patients need to be aware of this risk. It’s part of the differential diagnosis for any patient who develops either ground glass changes or other infiltrates on a CT scan, or who has symptoms,” Dr. Burstein added.
 

Investigating ILD in T-DXd trials

T-DXd (Enhertu) is an anti-HER2-antibody drug conjugate that contains a humanized anti-HER2 IgG1 monoclonal antibody akin to trastuzumab that is linked to DXd, a topoisomerase I inhibitor that is a derivative of exatecan.

It has been approved for use in patients with HER2-positive metastatic breast cancer after two other HER2 treatments fail in the United States and Europe, and after chemotherapy in Japan, noted Dr. Powell. This is largely due to the results from the phase 2, open-label DESTINY-Breast01 trial.

“In breast cancer, T-DXd continues to demonstrate clinically meaningful efficacy with a median duration of response of more than 20 months in a heavily pretreated population,” he said. Objective response rates seen in the DESTINY-Breast01 trial were around 60%, and the median progression-free survival was a little over 19 months.

To look at the issue of drug-related ILD events in patients treated with T-DXd for HER2-positive MBC, an independent adjudication committee was formed to look at all the imaging and clinical data from the DESTINY-Breast01 trial and two single-arm phase 1 trials (NCT02564900 and NCT03383692).

In all, data on 245 patients who had been treated with T-DXd at the approved dose of 5.4 mg/kg in those trials between August 2015 and June 2020 were analyzed.
 

Dealing with lung toxicity

“We are getting new drugs to improve the treatment of cancer, but they always come with a price in terms of toxicity,” observed David Cameron, MD, professor of medical oncology at Edinburgh University in Scotland. Dr. Cameron chaired the session.

“Several measures were taken to identify and mitigate ILD,” across all the T-DXd studies, Dr. Powell explained. As well as the independent adjudication committee, available guidelines were followed and updated on how to diagnose and treat drug-induced lung injuries, and a “safe use” campaign was run in 2019.

Many patients in the early MBC studies were recruited before these measures were in place, such as the use of systemic steroids to manage low-grade events.

The bottom line, however, is that if a patient develops ILD then treatment should be stopped, Dr. Powell said. “Patients with grade 1 events may restart once the ILD has resolved, but those with grade 2 to 4 events must discontinue treatment.”

Dr. Powell concluded: “The overall clinical data support the positive risk-benefit profile of T-DXd. Phase 3 randomized controlled trials in breast cancer are ongoing.”
 

ILD also seen in monarchE trial with abemaciclib

Data on ILD events seen in the phase 3 monarchE trial were also reported separately at the ESMO Breast Cancer virtual meeting. The analysis population included 2,971 patients who had been treated with the CDK 4/6 inhibitor abemaciclib (Verzenio) together with endocrine therapy and 2,800 who had received endocrine therapy alone in the early-stage, adjuvant advanced breast cancer setting.

Most ILD (97%) events that occurred were single occurrences, with any grade of ILD occurring in a higher percentage of patients treated with abemaciclib with endocrine therapy than endocrine therapy alone (2.9% vs. 1.2%). Grade 3 events occurred in a respective 0.4% and 0.0% of patients.
 

So who’s at risk?

The risk factors for ILD and pneumonitis are not well characterized with either of the two drugs discussed, Dr. Burstein observed.

“In the abemaciclib experience, it looked like obesity might be a predisposing factor, with trastuzumab deruxtecan, it looked like patients of Asian ancestry were greater risk, but we need more data to really understand who’s at jeopardy.”

Dr. Burstein observed: “This is something patients need to be aware of as they’re contemplating this treatment.”

While data to prove the benefit of the drug need to mature, Dr. Burstein “would likely discontinue therapy” if a patient were to develop ILD or pneumonitis and treat accordingly.

As for T-DXd, he said: “It’s important that patients know that lung disease is a potentially severe side effect of treatment and that any respiratory symptoms need to be jumped on quickly.”

While prospective studies are now needed, and the phase 3 data should help to better understand the risk of ILD with T-DXd, Dr. Burstein believes it will be important to develop algorithms to ensure the safe administration of the drug.

These algorithms should include “appropriate surveillance and monitoring, especially as we think about trying to move this drug forward into the early stage setting where we’re using it in women who have favorable prognosis, and potentially curative situations for breast cancer.”

The trastuzumab deruxtecan trials were cosponsored by Daiichi Sankyo and AstraZeneca. The monarchE trial was supported by Eli Lilly.

Dr. Powell acknowledged receiving personal fees for acting as an advisory or consultant to both companies as well as to Voluntis. Dr. Burstein had nothing to disclose, and Dr. Cameron had no relevant financial interests in the data being presented.

Although rates are generally low, interstitial lung disease (ILD) can occur at any point in the first year of treatment with trastuzumab deruxtecan (T-DXd) for HER2-positive metastatic breast cancer (MBC).

That’s according to a pooled analysis of three early clinical trials with the drug that was reported at the European Society for Medical Oncology (ESMO): Breast Cancer virtual meeting.

Over a 5-year analysis period, the rate of any grade of ILD was 15.5%. The majority (79%) of those events were grade 1 or 2, observed pulmonologist Charles A. Powell, MD, of Icahn School of Medicine at Mount Sinai in New York, who presented the findings.

Of the 245 patients who were included in the analysis, 38 had an ILD event deemed related to treatment. A respective 9 (3.7%) and 21 (8.6%) had events graded as 1 or 2, 1 patient each (0.4%) had a grade 3 or 4 event, and 6 (2.4%) patients had a grade 5 event.

The timing of the first identified ILD event varied from 1.1 months to 20.8 months, given a median of 5.6 months overall. “This highlights an opportunity for more timely detection of ILD,” Dr. Powell suggested. He added that in almost all (97%) cases, ILD occurred before 12 months and the risk may even decrease over time “suggesting that the risk is not cumulative.”

He cautioned, however: “It is important to note that this analysis is exploratory and hypothesis generating in nature.”
 

ILD occurs with other cancer drugs

ILD is not just associated with T-DXd treatment, said the invited discussant for the trial, Harold J. Burstein, MD, PhD, of the Dana-Farber Cancer Institute in Boston.

“It’s important for clinicians to remember that ILD/pneumonitis is an uncommon, but potentially very serious side effect that affects many breast cancer treatments,” he said.

That not only includes T-DXd, but other newer drugs such the cyclin dependent kinase (CDK) 4/6 inhibitors and immune checkpoint inhibitors, as well as other older more established drugs including taxanes, cyclophosphamide and even the mTOR inhibitor everolimus.

“Both clinicians and patients need to be aware of this risk. It’s part of the differential diagnosis for any patient who develops either ground glass changes or other infiltrates on a CT scan, or who has symptoms,” Dr. Burstein added.
 

Investigating ILD in T-DXd trials

T-DXd (Enhertu) is an anti-HER2-antibody drug conjugate that contains a humanized anti-HER2 IgG1 monoclonal antibody akin to trastuzumab that is linked to DXd, a topoisomerase I inhibitor that is a derivative of exatecan.

It has been approved for use in patients with HER2-positive metastatic breast cancer after two other HER2 treatments fail in the United States and Europe, and after chemotherapy in Japan, noted Dr. Powell. This is largely due to the results from the phase 2, open-label DESTINY-Breast01 trial.

“In breast cancer, T-DXd continues to demonstrate clinically meaningful efficacy with a median duration of response of more than 20 months in a heavily pretreated population,” he said. Objective response rates seen in the DESTINY-Breast01 trial were around 60%, and the median progression-free survival was a little over 19 months.

To look at the issue of drug-related ILD events in patients treated with T-DXd for HER2-positive MBC, an independent adjudication committee was formed to look at all the imaging and clinical data from the DESTINY-Breast01 trial and two single-arm phase 1 trials (NCT02564900 and NCT03383692).

In all, data on 245 patients who had been treated with T-DXd at the approved dose of 5.4 mg/kg in those trials between August 2015 and June 2020 were analyzed.
 

Dealing with lung toxicity

“We are getting new drugs to improve the treatment of cancer, but they always come with a price in terms of toxicity,” observed David Cameron, MD, professor of medical oncology at Edinburgh University in Scotland. Dr. Cameron chaired the session.

“Several measures were taken to identify and mitigate ILD,” across all the T-DXd studies, Dr. Powell explained. As well as the independent adjudication committee, available guidelines were followed and updated on how to diagnose and treat drug-induced lung injuries, and a “safe use” campaign was run in 2019.

Many patients in the early MBC studies were recruited before these measures were in place, such as the use of systemic steroids to manage low-grade events.

The bottom line, however, is that if a patient develops ILD then treatment should be stopped, Dr. Powell said. “Patients with grade 1 events may restart once the ILD has resolved, but those with grade 2 to 4 events must discontinue treatment.”

Dr. Powell concluded: “The overall clinical data support the positive risk-benefit profile of T-DXd. Phase 3 randomized controlled trials in breast cancer are ongoing.”
 

ILD also seen in monarchE trial with abemaciclib

Data on ILD events seen in the phase 3 monarchE trial were also reported separately at the ESMO Breast Cancer virtual meeting. The analysis population included 2,971 patients who had been treated with the CDK 4/6 inhibitor abemaciclib (Verzenio) together with endocrine therapy and 2,800 who had received endocrine therapy alone in the early-stage, adjuvant advanced breast cancer setting.

Most ILD (97%) events that occurred were single occurrences, with any grade of ILD occurring in a higher percentage of patients treated with abemaciclib with endocrine therapy than endocrine therapy alone (2.9% vs. 1.2%). Grade 3 events occurred in a respective 0.4% and 0.0% of patients.
 

So who’s at risk?

The risk factors for ILD and pneumonitis are not well characterized with either of the two drugs discussed, Dr. Burstein observed.

“In the abemaciclib experience, it looked like obesity might be a predisposing factor, with trastuzumab deruxtecan, it looked like patients of Asian ancestry were greater risk, but we need more data to really understand who’s at jeopardy.”

Dr. Burstein observed: “This is something patients need to be aware of as they’re contemplating this treatment.”

While data to prove the benefit of the drug need to mature, Dr. Burstein “would likely discontinue therapy” if a patient were to develop ILD or pneumonitis and treat accordingly.

As for T-DXd, he said: “It’s important that patients know that lung disease is a potentially severe side effect of treatment and that any respiratory symptoms need to be jumped on quickly.”

While prospective studies are now needed, and the phase 3 data should help to better understand the risk of ILD with T-DXd, Dr. Burstein believes it will be important to develop algorithms to ensure the safe administration of the drug.

These algorithms should include “appropriate surveillance and monitoring, especially as we think about trying to move this drug forward into the early stage setting where we’re using it in women who have favorable prognosis, and potentially curative situations for breast cancer.”

The trastuzumab deruxtecan trials were cosponsored by Daiichi Sankyo and AstraZeneca. The monarchE trial was supported by Eli Lilly.

Dr. Powell acknowledged receiving personal fees for acting as an advisory or consultant to both companies as well as to Voluntis. Dr. Burstein had nothing to disclose, and Dr. Cameron had no relevant financial interests in the data being presented.

In the past, chemotherapy was the go-to treatment for patients with HR+/HER2- breast cancer with visceral metastases, which most commonly involve lung and liver. Dr Adam M. Brufsky, of the University of Pittsburgh School of Medicine, reports that the advent of CDK4/6 inhibitors offers an opportunity for several different courses of action appropriate to subgroups within this population of patients.

Three CDK4/6 inhibitors are FDA approved for clinical practice. Dr Brufsky summarizes results from three studies of CDK4/6 inhibitors — abemaciclib, ribociclib, and palbociclib — where these agents were used as second-line therapy after progression on a nonsteroidal aromatase inhibitor. In combination with fulvestrant, all three offered significant benefits in progression-free survival (PFS) and two in overall survival (OS). Among those who derived survival benefit were patients who had visceral metatases, who constituted 56%, 27% and 60% of the respective studies.

For patients who show progression on CDK4/6 inhibitors, additional treatment can be determined by genomic sequencing. Combination therapy with alpelisib and fulvestrant has been shown to lengthen PFS in patients whose tumors have PIK3 mutations. Patients without PIK3 mutations can be treated with fulvestrant or a combination of fulvestrant and everolimus.

--

Adam M. Brufsky, MD, PhD, Professor, Department of Medicine, Division of Hematology-Oncology, University of Pittsburgh School of Medicine; Associate Chief, Department of Medicine, Division of Hematology-Oncology, UPMC-Hillman Cancer Center, Pittsburgh, Pennsylvania. 

Adam M. Brufsky, MD, PhD, has disclosed the following relevant financial relationships: 
Received income in an amount equal to or greater than $250 from: Seattle Genetics; Roche; AstraZeneca; Puma; Daiichi Sankyo.

In the past, chemotherapy was the go-to treatment for patients with HR+/HER2- breast cancer with visceral metastases, which most commonly involve lung and liver. Dr Adam M. Brufsky, of the University of Pittsburgh School of Medicine, reports that the advent of CDK4/6 inhibitors offers an opportunity for several different courses of action appropriate to subgroups within this population of patients.

Three CDK4/6 inhibitors are FDA approved for clinical practice. Dr Brufsky summarizes results from three studies of CDK4/6 inhibitors — abemaciclib, ribociclib, and palbociclib — where these agents were used as second-line therapy after progression on a nonsteroidal aromatase inhibitor. In combination with fulvestrant, all three offered significant benefits in progression-free survival (PFS) and two in overall survival (OS). Among those who derived survival benefit were patients who had visceral metatases, who constituted 56%, 27% and 60% of the respective studies.

For patients who show progression on CDK4/6 inhibitors, additional treatment can be determined by genomic sequencing. Combination therapy with alpelisib and fulvestrant has been shown to lengthen PFS in patients whose tumors have PIK3 mutations. Patients without PIK3 mutations can be treated with fulvestrant or a combination of fulvestrant and everolimus.

--

Adam M. Brufsky, MD, PhD, Professor, Department of Medicine, Division of Hematology-Oncology, University of Pittsburgh School of Medicine; Associate Chief, Department of Medicine, Division of Hematology-Oncology, UPMC-Hillman Cancer Center, Pittsburgh, Pennsylvania. 

Adam M. Brufsky, MD, PhD, has disclosed the following relevant financial relationships: 
Received income in an amount equal to or greater than $250 from: Seattle Genetics; Roche; AstraZeneca; Puma; Daiichi Sankyo.

In the past, chemotherapy was the go-to treatment for patients with HR+/HER2- breast cancer with visceral metastases, which most commonly involve lung and liver. Dr Adam M. Brufsky, of the University of Pittsburgh School of Medicine, reports that the advent of CDK4/6 inhibitors offers an opportunity for several different courses of action appropriate to subgroups within this population of patients.

Three CDK4/6 inhibitors are FDA approved for clinical practice. Dr Brufsky summarizes results from three studies of CDK4/6 inhibitors — abemaciclib, ribociclib, and palbociclib — where these agents were used as second-line therapy after progression on a nonsteroidal aromatase inhibitor. In combination with fulvestrant, all three offered significant benefits in progression-free survival (PFS) and two in overall survival (OS). Among those who derived survival benefit were patients who had visceral metatases, who constituted 56%, 27% and 60% of the respective studies.

For patients who show progression on CDK4/6 inhibitors, additional treatment can be determined by genomic sequencing. Combination therapy with alpelisib and fulvestrant has been shown to lengthen PFS in patients whose tumors have PIK3 mutations. Patients without PIK3 mutations can be treated with fulvestrant or a combination of fulvestrant and everolimus.

--

Adam M. Brufsky, MD, PhD, Professor, Department of Medicine, Division of Hematology-Oncology, University of Pittsburgh School of Medicine; Associate Chief, Department of Medicine, Division of Hematology-Oncology, UPMC-Hillman Cancer Center, Pittsburgh, Pennsylvania. 

Adam M. Brufsky, MD, PhD, has disclosed the following relevant financial relationships: 
Received income in an amount equal to or greater than $250 from: Seattle Genetics; Roche; AstraZeneca; Puma; Daiichi Sankyo.

The long-term benefits of endocrine therapy in premenopausal breast cancer appear to differ according to whether patients are categorized as high or low molecular risk using the 70-gene signature (MammaPrint).

Based upon data from patients who had participated in the Stockholm tamoxifen (STO-5) trial, high-risk patients significantly benefited from goserelin treatment, whereas low-risk patients benefited more from tamoxifen treatment when compared with no endocrine therapy.

“Goserelin, tamoxifen, and the combination of the two, reduced the 20-year risk of distant occurrences and fatal breast cancer, compared to no endocrine therapy,” Annelie Johansson, MSc, said at the European Society for Medical Oncology: Breast Cancer virtual meeting.

“Our findings indicate that the long-term endocrine therapy benefit in premenopausal patients is influenced by molecular risk classification and thus tumor characteristics,” she added.

Ms. Johansson, a postdoctoral researcher in genomic breast cancer at the Karolinska Institutet in Stockholm, reported the results of the analysis as a late-breaking abstract at the meeting.

“I think this is an innovative translational study trying to use the multigene assay results to look at differential endocrine therapy effects,” said Prudence Francis, MD, the invited discussant for study.

However, there are relatively few patients in the various subgroups being tested, she added. “We’ve also got short duration of tamoxifen, only 2 years, we’ve got prior chemotherapy in some patients and absence of HER2 therapy, all of which might influence outcomes.”

As a result, Dr. Francis, who is head of medical oncology at the Peter MacCallum Cancer Centre and a consultant Medical Oncologist at St. Vincent’s Hospital Melbourne, called the findings purely “hypothesis generating.”
 

Study details and results

The analysis was based on data from the STO-5 trial, which had recruited just over 900 patients between 1990 and 1997. Patients were stratified according to their lymph node status and some received chemotherapy with or without locoregional radiotherapy before being randomized to one of four study arms: goserelin alone, tamoxifen alone, the combination of the two, or no endocrine therapy.

Ms. Johansson noted that they were able to obtain the primary tumor blocks from 729 patients in the past year, of whom 610 were estrogen receptor positive. The analysis according to the 70-gene signature was then based on data from 465 patients: 131 had been treated with goserelin, 105 with tamoxifen, 120 with both, and 109 had received no endocrine treatment.

We have complete 20-year follow-up from high-quality Swedish National registries,” Ms. Johansson said, observing that the median age in the trial was 46 years.

Before stratifying patients into high and low risk using the 70-gene signature, the risk for having a distant recurrence, compared with no endocrine therapy was reduced by 52% with goserelin (hazard ratio, .48), 41% with tamoxifen (HR, 0.59), and 33% with both in combination (HR, 0.67).

After stratification, however, goserelin was associated with a 78% reduction of distant recurrence versus no endocrine treatment in high-risk patients (HR, 0.22) and a 20% reduction in low-risk patients (HR, 0.80).

Results in high- and low-risk patients with tamoxifen versus no endocrine treatment were a respective 31% reduction (HR, 0.69) and 62% reduction (HR, 0.38), and a respective 36% (HR, 0.64) and 28% (HR, 0.72) for the combination.

A further analysis was performed to compare between the active treatment arms, and this suggested a greater benefit of goserelin in patients at high risk when compared with both tamoxifen (HR, 0.30) and the combination (HR, 0.33).

Dr. Francis commented: “it is a bit surprising to find that goserelin appeared to be also better than the combination,” and it is something that the research team is looking into.

“One hypothesis might be if you look how the different treatments are working,” Ms. Johansson said. “Goserelin is very efficient in lowering the estrogen levels in premenopausal patients, suppressing the ovarian production of estrogen whereas tamoxifen can act both as an antagonist and agonist.

“So, we are thinking that maybe the addition of tamoxifen, with the agonistic properties of tamoxifen, might then make the goserelin not as efficient. But that’s of course, just a hypothesis right now and we need to look into this further,” she said.

The work was funded by The Swedish Research Council (Vetenskapsrådet), The Swedish Research Council for Health, Working life and Welfare, and the Swedish Cancer Society (Cancerfonden). Ms. Johansson had no personal disclosures; one of the coauthors was a coinventor of MammaPrint. Dr. Francis disclosed receiving travel support for overseas lectures from Ipsen and Novartis and acting as a medical oncology editor for Elsevier.

The long-term benefits of endocrine therapy in premenopausal breast cancer appear to differ according to whether patients are categorized as high or low molecular risk using the 70-gene signature (MammaPrint).

Based upon data from patients who had participated in the Stockholm tamoxifen (STO-5) trial, high-risk patients significantly benefited from goserelin treatment, whereas low-risk patients benefited more from tamoxifen treatment when compared with no endocrine therapy.

“Goserelin, tamoxifen, and the combination of the two, reduced the 20-year risk of distant occurrences and fatal breast cancer, compared to no endocrine therapy,” Annelie Johansson, MSc, said at the European Society for Medical Oncology: Breast Cancer virtual meeting.

“Our findings indicate that the long-term endocrine therapy benefit in premenopausal patients is influenced by molecular risk classification and thus tumor characteristics,” she added.

Ms. Johansson, a postdoctoral researcher in genomic breast cancer at the Karolinska Institutet in Stockholm, reported the results of the analysis as a late-breaking abstract at the meeting.

“I think this is an innovative translational study trying to use the multigene assay results to look at differential endocrine therapy effects,” said Prudence Francis, MD, the invited discussant for study.

However, there are relatively few patients in the various subgroups being tested, she added. “We’ve also got short duration of tamoxifen, only 2 years, we’ve got prior chemotherapy in some patients and absence of HER2 therapy, all of which might influence outcomes.”

As a result, Dr. Francis, who is head of medical oncology at the Peter MacCallum Cancer Centre and a consultant Medical Oncologist at St. Vincent’s Hospital Melbourne, called the findings purely “hypothesis generating.”
 

Study details and results

The analysis was based on data from the STO-5 trial, which had recruited just over 900 patients between 1990 and 1997. Patients were stratified according to their lymph node status and some received chemotherapy with or without locoregional radiotherapy before being randomized to one of four study arms: goserelin alone, tamoxifen alone, the combination of the two, or no endocrine therapy.

Ms. Johansson noted that they were able to obtain the primary tumor blocks from 729 patients in the past year, of whom 610 were estrogen receptor positive. The analysis according to the 70-gene signature was then based on data from 465 patients: 131 had been treated with goserelin, 105 with tamoxifen, 120 with both, and 109 had received no endocrine treatment.

We have complete 20-year follow-up from high-quality Swedish National registries,” Ms. Johansson said, observing that the median age in the trial was 46 years.

Before stratifying patients into high and low risk using the 70-gene signature, the risk for having a distant recurrence, compared with no endocrine therapy was reduced by 52% with goserelin (hazard ratio, .48), 41% with tamoxifen (HR, 0.59), and 33% with both in combination (HR, 0.67).

After stratification, however, goserelin was associated with a 78% reduction of distant recurrence versus no endocrine treatment in high-risk patients (HR, 0.22) and a 20% reduction in low-risk patients (HR, 0.80).

Results in high- and low-risk patients with tamoxifen versus no endocrine treatment were a respective 31% reduction (HR, 0.69) and 62% reduction (HR, 0.38), and a respective 36% (HR, 0.64) and 28% (HR, 0.72) for the combination.

A further analysis was performed to compare between the active treatment arms, and this suggested a greater benefit of goserelin in patients at high risk when compared with both tamoxifen (HR, 0.30) and the combination (HR, 0.33).

Dr. Francis commented: “it is a bit surprising to find that goserelin appeared to be also better than the combination,” and it is something that the research team is looking into.

“One hypothesis might be if you look how the different treatments are working,” Ms. Johansson said. “Goserelin is very efficient in lowering the estrogen levels in premenopausal patients, suppressing the ovarian production of estrogen whereas tamoxifen can act both as an antagonist and agonist.

“So, we are thinking that maybe the addition of tamoxifen, with the agonistic properties of tamoxifen, might then make the goserelin not as efficient. But that’s of course, just a hypothesis right now and we need to look into this further,” she said.

The work was funded by The Swedish Research Council (Vetenskapsrådet), The Swedish Research Council for Health, Working life and Welfare, and the Swedish Cancer Society (Cancerfonden). Ms. Johansson had no personal disclosures; one of the coauthors was a coinventor of MammaPrint. Dr. Francis disclosed receiving travel support for overseas lectures from Ipsen and Novartis and acting as a medical oncology editor for Elsevier.

The long-term benefits of endocrine therapy in premenopausal breast cancer appear to differ according to whether patients are categorized as high or low molecular risk using the 70-gene signature (MammaPrint).

Based upon data from patients who had participated in the Stockholm tamoxifen (STO-5) trial, high-risk patients significantly benefited from goserelin treatment, whereas low-risk patients benefited more from tamoxifen treatment when compared with no endocrine therapy.

“Goserelin, tamoxifen, and the combination of the two, reduced the 20-year risk of distant occurrences and fatal breast cancer, compared to no endocrine therapy,” Annelie Johansson, MSc, said at the European Society for Medical Oncology: Breast Cancer virtual meeting.

“Our findings indicate that the long-term endocrine therapy benefit in premenopausal patients is influenced by molecular risk classification and thus tumor characteristics,” she added.

Ms. Johansson, a postdoctoral researcher in genomic breast cancer at the Karolinska Institutet in Stockholm, reported the results of the analysis as a late-breaking abstract at the meeting.

“I think this is an innovative translational study trying to use the multigene assay results to look at differential endocrine therapy effects,” said Prudence Francis, MD, the invited discussant for study.

However, there are relatively few patients in the various subgroups being tested, she added. “We’ve also got short duration of tamoxifen, only 2 years, we’ve got prior chemotherapy in some patients and absence of HER2 therapy, all of which might influence outcomes.”

As a result, Dr. Francis, who is head of medical oncology at the Peter MacCallum Cancer Centre and a consultant Medical Oncologist at St. Vincent’s Hospital Melbourne, called the findings purely “hypothesis generating.”
 

Study details and results

The analysis was based on data from the STO-5 trial, which had recruited just over 900 patients between 1990 and 1997. Patients were stratified according to their lymph node status and some received chemotherapy with or without locoregional radiotherapy before being randomized to one of four study arms: goserelin alone, tamoxifen alone, the combination of the two, or no endocrine therapy.

Ms. Johansson noted that they were able to obtain the primary tumor blocks from 729 patients in the past year, of whom 610 were estrogen receptor positive. The analysis according to the 70-gene signature was then based on data from 465 patients: 131 had been treated with goserelin, 105 with tamoxifen, 120 with both, and 109 had received no endocrine treatment.

We have complete 20-year follow-up from high-quality Swedish National registries,” Ms. Johansson said, observing that the median age in the trial was 46 years.

Before stratifying patients into high and low risk using the 70-gene signature, the risk for having a distant recurrence, compared with no endocrine therapy was reduced by 52% with goserelin (hazard ratio, .48), 41% with tamoxifen (HR, 0.59), and 33% with both in combination (HR, 0.67).

After stratification, however, goserelin was associated with a 78% reduction of distant recurrence versus no endocrine treatment in high-risk patients (HR, 0.22) and a 20% reduction in low-risk patients (HR, 0.80).

Results in high- and low-risk patients with tamoxifen versus no endocrine treatment were a respective 31% reduction (HR, 0.69) and 62% reduction (HR, 0.38), and a respective 36% (HR, 0.64) and 28% (HR, 0.72) for the combination.

A further analysis was performed to compare between the active treatment arms, and this suggested a greater benefit of goserelin in patients at high risk when compared with both tamoxifen (HR, 0.30) and the combination (HR, 0.33).

Dr. Francis commented: “it is a bit surprising to find that goserelin appeared to be also better than the combination,” and it is something that the research team is looking into.

“One hypothesis might be if you look how the different treatments are working,” Ms. Johansson said. “Goserelin is very efficient in lowering the estrogen levels in premenopausal patients, suppressing the ovarian production of estrogen whereas tamoxifen can act both as an antagonist and agonist.

“So, we are thinking that maybe the addition of tamoxifen, with the agonistic properties of tamoxifen, might then make the goserelin not as efficient. But that’s of course, just a hypothesis right now and we need to look into this further,” she said.

The work was funded by The Swedish Research Council (Vetenskapsrådet), The Swedish Research Council for Health, Working life and Welfare, and the Swedish Cancer Society (Cancerfonden). Ms. Johansson had no personal disclosures; one of the coauthors was a coinventor of MammaPrint. Dr. Francis disclosed receiving travel support for overseas lectures from Ipsen and Novartis and acting as a medical oncology editor for Elsevier.

The landscape for therapies targeting HER2-positive metastatic breast cancer (MBC) has evolved rapidly in the past few years. In a 12-month window, the U.S. Food and Drug Administration approved four agents targeting human epidermal growth factor 2 (HER2)–positive MBC, starting with trastuzumab deruxtecan in December 2019, followed by neratinib and tucatinib a few months later, and margetuximab last December.

Although first-line therapy for the majority of patients continues to be the CLEOPATRA regimen — the monoclonal antibodies trastuzumab and pertuzumab plus a taxane, such as docetaxel or paclitaxel — the influx of agents approved in the metastatic setting has opened up new avenues for second-line therapy and beyond.

“We have been really fortunate to see a number of highly effective new therapies approved for HER2-positive MBC in the past year, and this has given us even more options to offer our patients,” remarked Rita Nanda, MD, director of the Breast Oncology Program and associate professor of medicine at University of Chicago Medicine.

What considerations do experts weigh when sequencing HER2-positive MBC?

For Kelly McCann, MD, PhD, the order largely depends on balancing two factors: regimens that will provide the best efficacy in terms of patient survival and quality of life. “In the metastatic setting, I know I’m going to end up using all of the available medications one after the other, so the order that allows patients to continue living their best life for as long as possible is essential,” commented Dr. McCann, a hematologist/oncologist in the department of medicine at the David Geffen School of Medicine, University of California, Los Angeles.

A new second-line option?

Before the wave of drug approvals for metastatic HER2-positive disease last year, oncologists routinely looked to trastuzumab emtansine (T-DM1) as second-line therapy.

But tucatinib may also now be considered in the second-line setting, after results from the HER2CLIMB trial. The decision between tucatinib and T-DM1 largely comes down to the presence or absence of brain metastases.

“T-DM1 is well-tolerated, so it’s still my go-to in the second-line setting unless my patient has a brain metastasis, in which case I opt for tucatinib,” Dr. McCann noted, adding that the HER2-specific oral tyrosine kinase inhibitor (TKI) not only crosses the blood-brain barrier but is also effective in patients with untreated brain metastases.

In HER2CLIMB, tucatinib exhibited strong efficacy in patients with advanced HER2-positive disease, including those with previously treated or untreated brain metastases. The randomized controlled trial, which paired tucatinib with trastuzumab and capecitabine, showed median progression-free survival of 7.8 months in 410 patients with HER2-positive MBC compared with 5.6 months in the 202 patients receiving the placebo regimen. The tucatinib cohort showed an overall survival advantage compared with the placebo group (21.9 vs 17.4 months).

Perhaps the most notable finding occurred in patients with brain or central nervous system (CNS) involvement, which develops in as many as half of patients with HER-positive MBC and is associated with shorter survival. In the HER2CLIMB trial, median progression-free survival was 7.6 months in patients with brain metastases compared with 5.4 months in the placebo group.

A follow-up exploratory analysis, which focused on 291 patients with brain metastases, found that adding tucatinib reduced the risk for intracranial progression by two thirds and death by almost half. In patients with active brain metastases, median progression-free survival reached 9.5 months vs 4.1 months in the placebo group. Those with stable metastases also benefited from tucatinib, with median progression-free survival of 13.9 vs 5.6 months in the placebo group.

On the basis of the results, the authors concluded that this randomized trial was the first to demonstrate improvements in both CNS progression–free survival and overall survival in patients with HER2-positive MBC and brain metastases.

Evolving options in the third-line setting and after

For third-line therapy and beyond, oncologists have an array of newer agents to choose from alongside longer-standing options — which include trastuzumab plus lapatinib, trastuzumab or lapatinib plus capecitabine, as well as T-DM1, if not given as second-line therapy.

According to Dr. McCann, the antibody-drug conjugate trastuzumab deruxtecan has been a particularly exciting addition to third-line treatment. In the phase 2 DESTINY-01 trial, more than 60% of a heavily pretreated population showed an objective response to trastuzumab deruxtecan, with a median response duration of almost 15 months and a median progression-free survival of 16.4 months. Longer-term follow-up results, presented in December at the 2020 San Antonio Breast Cancer Symposium, revealed progression-free survival of 19.4 months and preliminary median overall survival of 24.6 months.

Neratinib, the second TKI to bridge the blood-brain barrier in HER2-positive disease, was also approved for third-line use; however, Sayeh Lavasani, MD, MS, said she is more likely to consider this agent later in the sequence, potentially in the fourth-line setting and beyond, given the more robust outcomes observed in the HER2CLIMB tucatinib trial.

“Neratinib improved progression-free survival and time to intervention for CNS metastasis but, unlike tucatinib, did not demonstrate an overall survival benefit,” remarked Dr. Lavasani, a medical oncologist at City of Hope, a comprehensive cancer center in Los Angeles County.

More specifically, the phase 3 NALA trial, which randomly assigned patients to receive neratinib plus capecitabine or lapatinib plus capecitabine, reported progression-free survival of 8.8 months in the neratinib group compared with 6.6 months in the control arm but no significant gains in overall survival (hazard ratio, 0.88; P = .2098).

The fourth recently approved drug, margetuximab, has not yet made a significant mark on sequencing decisions for Dr. McCann.

“Margetuximab could have been a potential game changer, but clinical trial results were underwhelming,” she said.

In the phase 3 randomized clinical SOPHIA trial, margetuximab plus chemotherapy prolonged median progression-free survival by just over 1 month compared with trastuzumab plus chemotherapy. Preliminary overall survival data showed a slight, but not significant, benefit in the margetuximab group (21.6 vs 19.8 months).

For Dr. Lavasani, the presence of brain metastases is the most important consideration when weighing sequencing options. “For some of my patients with HER2-positive MBC, it’s ultimately disease progression in the brain that takes their life,” she said.

Aside from CNS metastases, specific sequencing choices may vary on the basis of drug-related tolerance as well as patient preferences. “It is critical to get a patient’s input in treatment selection,” Dr. Nanda remarked. “Given the number of effective treatments for HER2-positive MBC and the lack of data to guide how to sequence these regimens, it is important to ask patients what their preferences are.”

Dr. McCann agreed, noting that “a patient with HER2-positive MBC typically has a life expectancy measured in years, which is also why sequencing should be influenced by quality of life considerations.”

Convenience, side-effect profile, and financial toxicity should factor into clinical decision-making, according to Dr. Nanda. Some patients may, for instance, prefer a combination of tucatinib, capecitabine, and trastuzumab over trastuzumab deruxtecan to avoid hair loss and the risk for interstitial lung disease, which has been reported in more than 13% of patients, whereas others may prefer trastuzumab deruxtecan to avoid the possibility of diarrhea.

Taxanes come with a high risk for infusion reactions — which occur in about 30% of patients — and can cause neuropathy as well as hair loss and severe gastrointestinal side effects. In first-line care, Dr. McCann typically stops the taxane at some point for toxicity reasons and continues with trastuzumab plus pertuzumab until disease progression.

Even with an array of new options for treating metastatic HER2-positive disease, ultimately drug resistance does occur, Dr. Lavasani cautioned. Several ongoing trials are exploring new combinations of existing drugs to see whether those variations move the needle on survival outcomes. The HER2CLIMB-04 trial, for instance, is pairing tucatinib with trastuzumab deruxtecan, whereas HER2CLIMB-02 is pairing tucatinib with T-DM1.

But given progress in drug development in just the past few years, Lisa A. Carey, MD, deputy director of Clinical Sciences at the University of North Carolina Lineberger Comprehensive Cancer Center in Chapel Hill, sees a promising future for treating metastatic HER2-positive disease. “There is so much going on in the HER2-positive MBC therapeutics space that almost every 6 months, oncologists have to regroup and reevaluate treatment and sequencing, which is a great position to be in,” Dr. Carey noted.

A version of this article first appeared on Medscape.com .

The landscape for therapies targeting HER2-positive metastatic breast cancer (MBC) has evolved rapidly in the past few years. In a 12-month window, the U.S. Food and Drug Administration approved four agents targeting human epidermal growth factor 2 (HER2)–positive MBC, starting with trastuzumab deruxtecan in December 2019, followed by neratinib and tucatinib a few months later, and margetuximab last December.

Although first-line therapy for the majority of patients continues to be the CLEOPATRA regimen — the monoclonal antibodies trastuzumab and pertuzumab plus a taxane, such as docetaxel or paclitaxel — the influx of agents approved in the metastatic setting has opened up new avenues for second-line therapy and beyond.

“We have been really fortunate to see a number of highly effective new therapies approved for HER2-positive MBC in the past year, and this has given us even more options to offer our patients,” remarked Rita Nanda, MD, director of the Breast Oncology Program and associate professor of medicine at University of Chicago Medicine.

What considerations do experts weigh when sequencing HER2-positive MBC?

For Kelly McCann, MD, PhD, the order largely depends on balancing two factors: regimens that will provide the best efficacy in terms of patient survival and quality of life. “In the metastatic setting, I know I’m going to end up using all of the available medications one after the other, so the order that allows patients to continue living their best life for as long as possible is essential,” commented Dr. McCann, a hematologist/oncologist in the department of medicine at the David Geffen School of Medicine, University of California, Los Angeles.

A new second-line option?

Before the wave of drug approvals for metastatic HER2-positive disease last year, oncologists routinely looked to trastuzumab emtansine (T-DM1) as second-line therapy.

But tucatinib may also now be considered in the second-line setting, after results from the HER2CLIMB trial. The decision between tucatinib and T-DM1 largely comes down to the presence or absence of brain metastases.

“T-DM1 is well-tolerated, so it’s still my go-to in the second-line setting unless my patient has a brain metastasis, in which case I opt for tucatinib,” Dr. McCann noted, adding that the HER2-specific oral tyrosine kinase inhibitor (TKI) not only crosses the blood-brain barrier but is also effective in patients with untreated brain metastases.

In HER2CLIMB, tucatinib exhibited strong efficacy in patients with advanced HER2-positive disease, including those with previously treated or untreated brain metastases. The randomized controlled trial, which paired tucatinib with trastuzumab and capecitabine, showed median progression-free survival of 7.8 months in 410 patients with HER2-positive MBC compared with 5.6 months in the 202 patients receiving the placebo regimen. The tucatinib cohort showed an overall survival advantage compared with the placebo group (21.9 vs 17.4 months).

Perhaps the most notable finding occurred in patients with brain or central nervous system (CNS) involvement, which develops in as many as half of patients with HER-positive MBC and is associated with shorter survival. In the HER2CLIMB trial, median progression-free survival was 7.6 months in patients with brain metastases compared with 5.4 months in the placebo group.

A follow-up exploratory analysis, which focused on 291 patients with brain metastases, found that adding tucatinib reduced the risk for intracranial progression by two thirds and death by almost half. In patients with active brain metastases, median progression-free survival reached 9.5 months vs 4.1 months in the placebo group. Those with stable metastases also benefited from tucatinib, with median progression-free survival of 13.9 vs 5.6 months in the placebo group.

On the basis of the results, the authors concluded that this randomized trial was the first to demonstrate improvements in both CNS progression–free survival and overall survival in patients with HER2-positive MBC and brain metastases.

Evolving options in the third-line setting and after

For third-line therapy and beyond, oncologists have an array of newer agents to choose from alongside longer-standing options — which include trastuzumab plus lapatinib, trastuzumab or lapatinib plus capecitabine, as well as T-DM1, if not given as second-line therapy.

According to Dr. McCann, the antibody-drug conjugate trastuzumab deruxtecan has been a particularly exciting addition to third-line treatment. In the phase 2 DESTINY-01 trial, more than 60% of a heavily pretreated population showed an objective response to trastuzumab deruxtecan, with a median response duration of almost 15 months and a median progression-free survival of 16.4 months. Longer-term follow-up results, presented in December at the 2020 San Antonio Breast Cancer Symposium, revealed progression-free survival of 19.4 months and preliminary median overall survival of 24.6 months.

Neratinib, the second TKI to bridge the blood-brain barrier in HER2-positive disease, was also approved for third-line use; however, Sayeh Lavasani, MD, MS, said she is more likely to consider this agent later in the sequence, potentially in the fourth-line setting and beyond, given the more robust outcomes observed in the HER2CLIMB tucatinib trial.

“Neratinib improved progression-free survival and time to intervention for CNS metastasis but, unlike tucatinib, did not demonstrate an overall survival benefit,” remarked Dr. Lavasani, a medical oncologist at City of Hope, a comprehensive cancer center in Los Angeles County.

More specifically, the phase 3 NALA trial, which randomly assigned patients to receive neratinib plus capecitabine or lapatinib plus capecitabine, reported progression-free survival of 8.8 months in the neratinib group compared with 6.6 months in the control arm but no significant gains in overall survival (hazard ratio, 0.88; P = .2098).

The fourth recently approved drug, margetuximab, has not yet made a significant mark on sequencing decisions for Dr. McCann.

“Margetuximab could have been a potential game changer, but clinical trial results were underwhelming,” she said.

In the phase 3 randomized clinical SOPHIA trial, margetuximab plus chemotherapy prolonged median progression-free survival by just over 1 month compared with trastuzumab plus chemotherapy. Preliminary overall survival data showed a slight, but not significant, benefit in the margetuximab group (21.6 vs 19.8 months).

For Dr. Lavasani, the presence of brain metastases is the most important consideration when weighing sequencing options. “For some of my patients with HER2-positive MBC, it’s ultimately disease progression in the brain that takes their life,” she said.

Aside from CNS metastases, specific sequencing choices may vary on the basis of drug-related tolerance as well as patient preferences. “It is critical to get a patient’s input in treatment selection,” Dr. Nanda remarked. “Given the number of effective treatments for HER2-positive MBC and the lack of data to guide how to sequence these regimens, it is important to ask patients what their preferences are.”

Dr. McCann agreed, noting that “a patient with HER2-positive MBC typically has a life expectancy measured in years, which is also why sequencing should be influenced by quality of life considerations.”

Convenience, side-effect profile, and financial toxicity should factor into clinical decision-making, according to Dr. Nanda. Some patients may, for instance, prefer a combination of tucatinib, capecitabine, and trastuzumab over trastuzumab deruxtecan to avoid hair loss and the risk for interstitial lung disease, which has been reported in more than 13% of patients, whereas others may prefer trastuzumab deruxtecan to avoid the possibility of diarrhea.

Taxanes come with a high risk for infusion reactions — which occur in about 30% of patients — and can cause neuropathy as well as hair loss and severe gastrointestinal side effects. In first-line care, Dr. McCann typically stops the taxane at some point for toxicity reasons and continues with trastuzumab plus pertuzumab until disease progression.

Even with an array of new options for treating metastatic HER2-positive disease, ultimately drug resistance does occur, Dr. Lavasani cautioned. Several ongoing trials are exploring new combinations of existing drugs to see whether those variations move the needle on survival outcomes. The HER2CLIMB-04 trial, for instance, is pairing tucatinib with trastuzumab deruxtecan, whereas HER2CLIMB-02 is pairing tucatinib with T-DM1.

But given progress in drug development in just the past few years, Lisa A. Carey, MD, deputy director of Clinical Sciences at the University of North Carolina Lineberger Comprehensive Cancer Center in Chapel Hill, sees a promising future for treating metastatic HER2-positive disease. “There is so much going on in the HER2-positive MBC therapeutics space that almost every 6 months, oncologists have to regroup and reevaluate treatment and sequencing, which is a great position to be in,” Dr. Carey noted.

A version of this article first appeared on Medscape.com .

The landscape for therapies targeting HER2-positive metastatic breast cancer (MBC) has evolved rapidly in the past few years. In a 12-month window, the U.S. Food and Drug Administration approved four agents targeting human epidermal growth factor 2 (HER2)–positive MBC, starting with trastuzumab deruxtecan in December 2019, followed by neratinib and tucatinib a few months later, and margetuximab last December.

Although first-line therapy for the majority of patients continues to be the CLEOPATRA regimen — the monoclonal antibodies trastuzumab and pertuzumab plus a taxane, such as docetaxel or paclitaxel — the influx of agents approved in the metastatic setting has opened up new avenues for second-line therapy and beyond.

“We have been really fortunate to see a number of highly effective new therapies approved for HER2-positive MBC in the past year, and this has given us even more options to offer our patients,” remarked Rita Nanda, MD, director of the Breast Oncology Program and associate professor of medicine at University of Chicago Medicine.

What considerations do experts weigh when sequencing HER2-positive MBC?

For Kelly McCann, MD, PhD, the order largely depends on balancing two factors: regimens that will provide the best efficacy in terms of patient survival and quality of life. “In the metastatic setting, I know I’m going to end up using all of the available medications one after the other, so the order that allows patients to continue living their best life for as long as possible is essential,” commented Dr. McCann, a hematologist/oncologist in the department of medicine at the David Geffen School of Medicine, University of California, Los Angeles.

A new second-line option?

Before the wave of drug approvals for metastatic HER2-positive disease last year, oncologists routinely looked to trastuzumab emtansine (T-DM1) as second-line therapy.

But tucatinib may also now be considered in the second-line setting, after results from the HER2CLIMB trial. The decision between tucatinib and T-DM1 largely comes down to the presence or absence of brain metastases.

“T-DM1 is well-tolerated, so it’s still my go-to in the second-line setting unless my patient has a brain metastasis, in which case I opt for tucatinib,” Dr. McCann noted, adding that the HER2-specific oral tyrosine kinase inhibitor (TKI) not only crosses the blood-brain barrier but is also effective in patients with untreated brain metastases.

In HER2CLIMB, tucatinib exhibited strong efficacy in patients with advanced HER2-positive disease, including those with previously treated or untreated brain metastases. The randomized controlled trial, which paired tucatinib with trastuzumab and capecitabine, showed median progression-free survival of 7.8 months in 410 patients with HER2-positive MBC compared with 5.6 months in the 202 patients receiving the placebo regimen. The tucatinib cohort showed an overall survival advantage compared with the placebo group (21.9 vs 17.4 months).

Perhaps the most notable finding occurred in patients with brain or central nervous system (CNS) involvement, which develops in as many as half of patients with HER-positive MBC and is associated with shorter survival. In the HER2CLIMB trial, median progression-free survival was 7.6 months in patients with brain metastases compared with 5.4 months in the placebo group.

A follow-up exploratory analysis, which focused on 291 patients with brain metastases, found that adding tucatinib reduced the risk for intracranial progression by two thirds and death by almost half. In patients with active brain metastases, median progression-free survival reached 9.5 months vs 4.1 months in the placebo group. Those with stable metastases also benefited from tucatinib, with median progression-free survival of 13.9 vs 5.6 months in the placebo group.

On the basis of the results, the authors concluded that this randomized trial was the first to demonstrate improvements in both CNS progression–free survival and overall survival in patients with HER2-positive MBC and brain metastases.

Evolving options in the third-line setting and after

For third-line therapy and beyond, oncologists have an array of newer agents to choose from alongside longer-standing options — which include trastuzumab plus lapatinib, trastuzumab or lapatinib plus capecitabine, as well as T-DM1, if not given as second-line therapy.

According to Dr. McCann, the antibody-drug conjugate trastuzumab deruxtecan has been a particularly exciting addition to third-line treatment. In the phase 2 DESTINY-01 trial, more than 60% of a heavily pretreated population showed an objective response to trastuzumab deruxtecan, with a median response duration of almost 15 months and a median progression-free survival of 16.4 months. Longer-term follow-up results, presented in December at the 2020 San Antonio Breast Cancer Symposium, revealed progression-free survival of 19.4 months and preliminary median overall survival of 24.6 months.

Neratinib, the second TKI to bridge the blood-brain barrier in HER2-positive disease, was also approved for third-line use; however, Sayeh Lavasani, MD, MS, said she is more likely to consider this agent later in the sequence, potentially in the fourth-line setting and beyond, given the more robust outcomes observed in the HER2CLIMB tucatinib trial.

“Neratinib improved progression-free survival and time to intervention for CNS metastasis but, unlike tucatinib, did not demonstrate an overall survival benefit,” remarked Dr. Lavasani, a medical oncologist at City of Hope, a comprehensive cancer center in Los Angeles County.

More specifically, the phase 3 NALA trial, which randomly assigned patients to receive neratinib plus capecitabine or lapatinib plus capecitabine, reported progression-free survival of 8.8 months in the neratinib group compared with 6.6 months in the control arm but no significant gains in overall survival (hazard ratio, 0.88; P = .2098).

The fourth recently approved drug, margetuximab, has not yet made a significant mark on sequencing decisions for Dr. McCann.

“Margetuximab could have been a potential game changer, but clinical trial results were underwhelming,” she said.

In the phase 3 randomized clinical SOPHIA trial, margetuximab plus chemotherapy prolonged median progression-free survival by just over 1 month compared with trastuzumab plus chemotherapy. Preliminary overall survival data showed a slight, but not significant, benefit in the margetuximab group (21.6 vs 19.8 months).

For Dr. Lavasani, the presence of brain metastases is the most important consideration when weighing sequencing options. “For some of my patients with HER2-positive MBC, it’s ultimately disease progression in the brain that takes their life,” she said.

Aside from CNS metastases, specific sequencing choices may vary on the basis of drug-related tolerance as well as patient preferences. “It is critical to get a patient’s input in treatment selection,” Dr. Nanda remarked. “Given the number of effective treatments for HER2-positive MBC and the lack of data to guide how to sequence these regimens, it is important to ask patients what their preferences are.”

Dr. McCann agreed, noting that “a patient with HER2-positive MBC typically has a life expectancy measured in years, which is also why sequencing should be influenced by quality of life considerations.”

Convenience, side-effect profile, and financial toxicity should factor into clinical decision-making, according to Dr. Nanda. Some patients may, for instance, prefer a combination of tucatinib, capecitabine, and trastuzumab over trastuzumab deruxtecan to avoid hair loss and the risk for interstitial lung disease, which has been reported in more than 13% of patients, whereas others may prefer trastuzumab deruxtecan to avoid the possibility of diarrhea.

Taxanes come with a high risk for infusion reactions — which occur in about 30% of patients — and can cause neuropathy as well as hair loss and severe gastrointestinal side effects. In first-line care, Dr. McCann typically stops the taxane at some point for toxicity reasons and continues with trastuzumab plus pertuzumab until disease progression.

Even with an array of new options for treating metastatic HER2-positive disease, ultimately drug resistance does occur, Dr. Lavasani cautioned. Several ongoing trials are exploring new combinations of existing drugs to see whether those variations move the needle on survival outcomes. The HER2CLIMB-04 trial, for instance, is pairing tucatinib with trastuzumab deruxtecan, whereas HER2CLIMB-02 is pairing tucatinib with T-DM1.

But given progress in drug development in just the past few years, Lisa A. Carey, MD, deputy director of Clinical Sciences at the University of North Carolina Lineberger Comprehensive Cancer Center in Chapel Hill, sees a promising future for treating metastatic HER2-positive disease. “There is so much going on in the HER2-positive MBC therapeutics space that almost every 6 months, oncologists have to regroup and reevaluate treatment and sequencing, which is a great position to be in,” Dr. Carey noted.

A version of this article first appeared on Medscape.com .

Before 2001, HER2/neu-positive breast cancer (HER2+) was one of the most dreaded diagnoses a woman could face, as treatment was largely ineffective. The discovery of trastuzumab changed that dramatically.

Over the next 20 years, two additional HER2-targeted therapies – lapatinib and trastuzumab emtansine (TDM-1) – earned approval from the Food and Drug Administration for selected patients with early and late HER2+ breast cancer.

Since 2019, four additional HER2-targeted therapies have been approved by the FDA for HER2+ metastatic breast cancer (MBC), changing the treatment paradigm for those patients substantially.

The new agents are especially useful in certain patient populations. The agents offer the promise of improved survival for patients with recurrent metastatic disease and the potential for further reductions in relapse rates in earlier settings.
 

Trastuzumab deruxtecan

Trastuzumab deruxtecan is an antibody-drug conjugate that links three components: an anti-HER2 monoclonal antibody, a highly potent topoisomerase I inhibitor payload, and a tetrapeptide-based cleavable linker.

Trastuzumab deruxtecan has a high drug-to-antibody ratio. A membrane-permeable payload offers the potential for activity against adjacent HER2-negative cells in heterogeneous tumors. It has a long half-life (6 days).

Trastuzumab deruxtecan received accelerated approval from the FDA in December 2019 to treat patients with HER2+ MBC who have received two or more prior HER2-targeted regimens, based on the results of the DESTINY-Breast 01 trial.
 

DESTINY-Breast 01 trial

In the phase 2 DESTINY-Breast 01 trial, 184 patients with a median of six previous treatments received trastuzumab deruxtecan (5.4 mg/kg) intravenously every 21 days. There were 24 patients with treated, asymptomatic brain metastases who participated. Patients with untreated or symptomatic brain metastases were excluded.

Overall, a response to therapy was reported in 112 patients (60.9%), with 6.0% complete and 54.9% partial responses. Most of the patients for whom both baseline and postbaseline data were available had a reduction in tumor size.

The median time until response was 1.6 months, an interval that corresponded to the time until the first scheduled imaging. Three patients (1.6%) had progressive disease, and two patients (1.1%) could not be evaluated.

The median duration of follow-up was 11.1 months, and the median response duration was 14.8 months.

The median progression-free survival (PFS) was 16.4 months, and the median overall survival (OS) was not reached. The median PFS in the patients with brain involvement was 18.1 months.

The most common adverse events of grade 3 or higher were a decreased neutrophil count (20.7%), anemia (8.7%), and nausea (7.6%). Most concerning was that trastuzumab deruxtecan was associated with interstitial lung disease in 13.6% of patients.
 

Tucatinib

Tucatinib is an oral, highly selective HER2 tyrosine kinase inhibitor (TKI). In April 2020, it was approved by the FDA, in combination with trastuzumab and capecitabine, for adult patients with advanced unresectable or metastatic HER2+ breast cancer who have received one or more prior anti-HER2–based regimens for MBC. The approval included patients with brain metastases.

The recommended tucatinib dose is 300 mg orally twice a day in combination with trastuzumab (at the standard dose) and capecitabine (1,000 mg/m² given orally twice daily on days 1-14) on a 21-day cycle, until disease progression or unacceptable toxicity.
 

HER2CLIMB trial

The study that led to the approval of tucatinib was the HER2CLIMB trial. The trial enrolled 612 HER2+ MBC patients who had prior treatment with trastuzumab, pertuzumab, and T-DM1. Patients had received a median of 4 (range, 2-17) prior lines of HER2-targeted therapy.

The patients were randomized 2:1 to receive trastuzumab plus capecitabine and either tucatinib or an identical placebo twice daily.

The primary endpoint was PFS, evaluated in the initial 480 randomized patients. The median PFS was 7.8 months in the tucatinib arm and 5.6 months in the control arm (hazard ratio, 0.54; 95% confidence interval, 0.42-0.71; P < .001).

The confirmed overall response rate for patients with measurable disease was 40.6% in the tucatinib arm and 22.8% in the control arm (P = .001). The proportion of patients still in response at 12 months was 33.1% and 12.3%, respectively.

The median OS was 21.9 months in the tucatinib arm and 17.4 months in the placebo arm (HR, 0.66; 95% CI, 0.50-0.88; P = .005). At 24 months, 44.9% and 26.6% of patients, respectively, were still alive.

The most common grade 3 or higher adverse events (in the tucatinib and placebo arms, respectively) were palmar-plantar erythrodysesthesia syndrome (13.1% vs. 9.1%), diarrhea (12.9% vs. 8.6%), elevations in ALT and AST (approximately 5% vs. 0.5% for each), and fatigue (4.7% vs. 4.1%).
 

Tucatinib in patients with brain involvement

A unique feature of the HER2CLIMB study was that patients with MBC and untreated, symptomatic brain metastases were eligible. Patients with active, untreated central nervous system disease are excluded from virtually all other trials, especially drug-approval trials.

There were 291 patients with brain metastases in HER2CLIMB, 198 (48%) in the tucatinib arm and 93 (46%) in the control arm.

The risk of intracranial progression or death was reduced by 68% in the tucatinib arm (HR, 0.32; 95% CI, 0.22 to 0.48; P  < .0001).

The 1-year CNS-PFS rate was 40.2% in the tucatinib arm and 0% in the placebo arm. The median duration of CNS-PFS was 9.9 months and 4.2 months, respectively.

The risk of death was reduced by 42% in the tucatinib arm (HR, 0.58; 95% CI, 0.40-0.85; P = .005). The median OS was 18.1 months and 12.0 months, respectively.

There were more objective responses in the brain with tucatinib (47.3%) than with placebo (20.0%; P = .03). The median duration of response was 6.8 months and 3.0 months, respectively.

Particularly because of its CNS activity and lack of serious, long-term toxicity, tucatinib combination therapy represents an attractive new option for patients with HER2+ MBC.
 

Neratinib

Neratinib is an irreversible pan-HER TKI that was approved by the FDA in July 2017 for extended adjuvant therapy in patients with early-stage HER2+ breast cancer, following the use of trastuzumab-based therapy.

Long-term results of the ExteNet study led to the approval for use as extended adjuvant therapy.

In February 2020, neratinib was FDA approved in combination with capecitabine for patients with HER2+ MBC after two or more prior anti-HER2–based regimens. The more recent FDA approval was based on results of the NALA trial.
 

NALA trial

The phase 3 NALA trial included 621 patients with HER2+ MBC who had received at least two prior anti-HER2 based regimens.

Patients were randomized 1:1 to receive neratinib at 240 mg orally once daily on days 1-21 with capecitabine at 750 mg/m² orally twice daily on days 1-14 or lapatinib at 1,250 mg orally once daily on days 1-21 with capecitabine at 1,000 mg/m² orally twice daily on days 1-14 for each 21-day cycle. Patients were treated until disease progression or unacceptable toxicity.

The primary endpoints were PFS and OS by blinded, independent, central review.

The median PFS was 5.6 months in the neratinib arm and 5.5 months in the lapatinib arm (HR, 0.76; 95% CI, 0.63-0.93; P = .0059). The PFS rate at 12 months was 28.8% and 14.8%, respectively.

The median OS was 21.0 months in the neratinib arm and 18.7 months in the lapatinib arm (HR, 0.88; 95% CI, 0.72-1.07; P = .2086). The ORR was 32.8% and 26.7%, respectively. The median response duration was 8.5 months and 5.6 months, respectively.

Fewer interventions for CNS disease were required in the neratinib arm than in the lapatinib arm (cumulative incidence, 22.8% vs. 29.2%; P = .043). 

The most frequently reported grade 3-4 adverse reactions for the neratinib combination were diarrhea, nausea, vomiting, fatigue, and decreased appetite.

Grade 3 diarrhea occurred in 24.4% of those in the neratinib arm and 12.5% of those in the lapatinib arm. Antidiarrheal medication was used by 98.3% of patients receiving neratinib and 62.1% of patients receiving lapatinib.
 

Margetuximab-cmkb

Margetuximab is a chimeric Fc-engineered anti-HER2 monoclonal antibody that targets the same epitope as trastuzumab and exerts similar antiproliferative effects.

Compared with trastuzumab, margetuximab has higher affinity for both 158V (high-binding) and 158F (low-binding) alleles of the activating Fc receptor, CD16A. As a result, margetuximab enhances innate immunity, including CD16A-mediated antibody-dependent cellular cytotoxicity, more effectively than trastuzumab. Margetuximab also potentiates adaptive immunity, including enhanced clonality of the T-cell repertoire and induction of HER2-specific T- and B-cell responses.

In December 2020, margetuximab, in combination with chemotherapy, was approved by the FDA for patients with HER2+ MBC after two or more prior anti-HER2 regimens, at least one of which was for metastatic disease. The approved dose is 15 mg/kg IV every 3 weeks.

The study that led to margetuximab’s approval was the phase 3 SOPHIA trial.
 

SOPHIA trial

SOPHIA was a randomized trial of 536 patients with HER2+ MBC who had received prior treatment with other anti-HER2 therapies, including one to three lines of therapy for MBC.

Patients were randomly assigned 1:1 to receive margetuximab plus chemotherapy or trastuzumab plus chemotherapy. Assignment was stratified by chemotherapy choice (capecitabine, eribulin, gemcitabine, or vinorelbine), the number of previous lines of therapy for MBC, and disease extent.

Co–primary outcome measures were PFS by blinded, independent, central review and OS.

At the second interim analysis, the median PFS was 5.8 months in the margetuximab arm and 4.9 months in the trastuzumab arm (HR, 0.76; 95% CI, 0.59-0.98; P = .033). Results were more impressive in patients with CD16A genotypes containing a 158F allele. In this group, the median PFS was 6.9 months with margetuximab and 5.1 months with trastuzumab (HR, 0.68, 95% CI, 0.52-0.90; P = .005).

At the second interim analysis, the median OS was 21.6 months in the margetuximab arm and 19.8 months in the trastuzumab arm (HR, 0.89; 95% CI, 0.69-1.13; P = .33).

Subgroup data showed no differences in OS between the two arms for any subgroup except HER2+ MBC patients with an IHC score of 2 or higher. This is consistent with the postulated mechanism of action of margetuximab.

The confirmed ORR was 25% in the margetuximab arm and 14% in the trastuzumab arm, with similar durations of response between the study arms.

The most common adverse events in both arms (≥20%), regardless of causality, were fatigue, nausea, diarrhea, and neutropenia. Vomiting was common in the margetuximab arm, and anemia was common in the trastuzumab arm.

Grade 3 or higher adverse events occurred in 53.8% of patients receiving margetuximab and 52.6% of those receiving trastuzumab.

In view of margetuximab’s modest benefits in the SOPHIA trial, the ultimate role for margetuximab in HER2+ MBC may be restricted to patients with the CD16A-158F allele. A neoadjuvant trial is planned in that population.
 

Take-home messages

There are legitimate arguments regarding whether curing MBC is within reach for certain patient subsets, but there is no argument about whether the outlook for patients with HER2+ MBC has improved dramatically in recent years; it has.

The approval of four unique, new agents for the treatment of women with HER2+ MBC in relapse provides further improvements in outcome for these patients and distinctly different opportunities for tailoring treatment to the special circumstances of each patient (e.g., whether brain metastases are present, desire for oral therapy, comorbidities, experience with prior chemotherapy, etc).

When considered along with the potential for incorporating these drugs in earlier settings in well-designed clinical trials, these new drugs offer great promise to a group of patients who faced a dismal outcome just 2 decades ago.

Dr. Lyss was a community-based medical oncologist and clinical researcher for more than 35 years before his recent retirement. His clinical and research interests were focused on breast and lung cancers, as well as expanding clinical trial access to medically underserved populations. He is based in St. Louis. He has no conflicts of interest.

Before 2001, HER2/neu-positive breast cancer (HER2+) was one of the most dreaded diagnoses a woman could face, as treatment was largely ineffective. The discovery of trastuzumab changed that dramatically.

Over the next 20 years, two additional HER2-targeted therapies – lapatinib and trastuzumab emtansine (TDM-1) – earned approval from the Food and Drug Administration for selected patients with early and late HER2+ breast cancer.

Since 2019, four additional HER2-targeted therapies have been approved by the FDA for HER2+ metastatic breast cancer (MBC), changing the treatment paradigm for those patients substantially.

The new agents are especially useful in certain patient populations. The agents offer the promise of improved survival for patients with recurrent metastatic disease and the potential for further reductions in relapse rates in earlier settings.
 

Trastuzumab deruxtecan

Trastuzumab deruxtecan is an antibody-drug conjugate that links three components: an anti-HER2 monoclonal antibody, a highly potent topoisomerase I inhibitor payload, and a tetrapeptide-based cleavable linker.

Trastuzumab deruxtecan has a high drug-to-antibody ratio. A membrane-permeable payload offers the potential for activity against adjacent HER2-negative cells in heterogeneous tumors. It has a long half-life (6 days).

Trastuzumab deruxtecan received accelerated approval from the FDA in December 2019 to treat patients with HER2+ MBC who have received two or more prior HER2-targeted regimens, based on the results of the DESTINY-Breast 01 trial.
 

DESTINY-Breast 01 trial

In the phase 2 DESTINY-Breast 01 trial, 184 patients with a median of six previous treatments received trastuzumab deruxtecan (5.4 mg/kg) intravenously every 21 days. There were 24 patients with treated, asymptomatic brain metastases who participated. Patients with untreated or symptomatic brain metastases were excluded.

Overall, a response to therapy was reported in 112 patients (60.9%), with 6.0% complete and 54.9% partial responses. Most of the patients for whom both baseline and postbaseline data were available had a reduction in tumor size.

The median time until response was 1.6 months, an interval that corresponded to the time until the first scheduled imaging. Three patients (1.6%) had progressive disease, and two patients (1.1%) could not be evaluated.

The median duration of follow-up was 11.1 months, and the median response duration was 14.8 months.

The median progression-free survival (PFS) was 16.4 months, and the median overall survival (OS) was not reached. The median PFS in the patients with brain involvement was 18.1 months.

The most common adverse events of grade 3 or higher were a decreased neutrophil count (20.7%), anemia (8.7%), and nausea (7.6%). Most concerning was that trastuzumab deruxtecan was associated with interstitial lung disease in 13.6% of patients.
 

Tucatinib

Tucatinib is an oral, highly selective HER2 tyrosine kinase inhibitor (TKI). In April 2020, it was approved by the FDA, in combination with trastuzumab and capecitabine, for adult patients with advanced unresectable or metastatic HER2+ breast cancer who have received one or more prior anti-HER2–based regimens for MBC. The approval included patients with brain metastases.

The recommended tucatinib dose is 300 mg orally twice a day in combination with trastuzumab (at the standard dose) and capecitabine (1,000 mg/m² given orally twice daily on days 1-14) on a 21-day cycle, until disease progression or unacceptable toxicity.
 

HER2CLIMB trial

The study that led to the approval of tucatinib was the HER2CLIMB trial. The trial enrolled 612 HER2+ MBC patients who had prior treatment with trastuzumab, pertuzumab, and T-DM1. Patients had received a median of 4 (range, 2-17) prior lines of HER2-targeted therapy.

The patients were randomized 2:1 to receive trastuzumab plus capecitabine and either tucatinib or an identical placebo twice daily.

The primary endpoint was PFS, evaluated in the initial 480 randomized patients. The median PFS was 7.8 months in the tucatinib arm and 5.6 months in the control arm (hazard ratio, 0.54; 95% confidence interval, 0.42-0.71; P < .001).

The confirmed overall response rate for patients with measurable disease was 40.6% in the tucatinib arm and 22.8% in the control arm (P = .001). The proportion of patients still in response at 12 months was 33.1% and 12.3%, respectively.

The median OS was 21.9 months in the tucatinib arm and 17.4 months in the placebo arm (HR, 0.66; 95% CI, 0.50-0.88; P = .005). At 24 months, 44.9% and 26.6% of patients, respectively, were still alive.

The most common grade 3 or higher adverse events (in the tucatinib and placebo arms, respectively) were palmar-plantar erythrodysesthesia syndrome (13.1% vs. 9.1%), diarrhea (12.9% vs. 8.6%), elevations in ALT and AST (approximately 5% vs. 0.5% for each), and fatigue (4.7% vs. 4.1%).
 

Tucatinib in patients with brain involvement

A unique feature of the HER2CLIMB study was that patients with MBC and untreated, symptomatic brain metastases were eligible. Patients with active, untreated central nervous system disease are excluded from virtually all other trials, especially drug-approval trials.

There were 291 patients with brain metastases in HER2CLIMB, 198 (48%) in the tucatinib arm and 93 (46%) in the control arm.

The risk of intracranial progression or death was reduced by 68% in the tucatinib arm (HR, 0.32; 95% CI, 0.22 to 0.48; P  < .0001).

The 1-year CNS-PFS rate was 40.2% in the tucatinib arm and 0% in the placebo arm. The median duration of CNS-PFS was 9.9 months and 4.2 months, respectively.

The risk of death was reduced by 42% in the tucatinib arm (HR, 0.58; 95% CI, 0.40-0.85; P = .005). The median OS was 18.1 months and 12.0 months, respectively.

There were more objective responses in the brain with tucatinib (47.3%) than with placebo (20.0%; P = .03). The median duration of response was 6.8 months and 3.0 months, respectively.

Particularly because of its CNS activity and lack of serious, long-term toxicity, tucatinib combination therapy represents an attractive new option for patients with HER2+ MBC.
 

Neratinib

Neratinib is an irreversible pan-HER TKI that was approved by the FDA in July 2017 for extended adjuvant therapy in patients with early-stage HER2+ breast cancer, following the use of trastuzumab-based therapy.

Long-term results of the ExteNet study led to the approval for use as extended adjuvant therapy.

In February 2020, neratinib was FDA approved in combination with capecitabine for patients with HER2+ MBC after two or more prior anti-HER2–based regimens. The more recent FDA approval was based on results of the NALA trial.
 

NALA trial

The phase 3 NALA trial included 621 patients with HER2+ MBC who had received at least two prior anti-HER2 based regimens.

Patients were randomized 1:1 to receive neratinib at 240 mg orally once daily on days 1-21 with capecitabine at 750 mg/m² orally twice daily on days 1-14 or lapatinib at 1,250 mg orally once daily on days 1-21 with capecitabine at 1,000 mg/m² orally twice daily on days 1-14 for each 21-day cycle. Patients were treated until disease progression or unacceptable toxicity.

The primary endpoints were PFS and OS by blinded, independent, central review.

The median PFS was 5.6 months in the neratinib arm and 5.5 months in the lapatinib arm (HR, 0.76; 95% CI, 0.63-0.93; P = .0059). The PFS rate at 12 months was 28.8% and 14.8%, respectively.

The median OS was 21.0 months in the neratinib arm and 18.7 months in the lapatinib arm (HR, 0.88; 95% CI, 0.72-1.07; P = .2086). The ORR was 32.8% and 26.7%, respectively. The median response duration was 8.5 months and 5.6 months, respectively.

Fewer interventions for CNS disease were required in the neratinib arm than in the lapatinib arm (cumulative incidence, 22.8% vs. 29.2%; P = .043). 

The most frequently reported grade 3-4 adverse reactions for the neratinib combination were diarrhea, nausea, vomiting, fatigue, and decreased appetite.

Grade 3 diarrhea occurred in 24.4% of those in the neratinib arm and 12.5% of those in the lapatinib arm. Antidiarrheal medication was used by 98.3% of patients receiving neratinib and 62.1% of patients receiving lapatinib.
 

Margetuximab-cmkb

Margetuximab is a chimeric Fc-engineered anti-HER2 monoclonal antibody that targets the same epitope as trastuzumab and exerts similar antiproliferative effects.

Compared with trastuzumab, margetuximab has higher affinity for both 158V (high-binding) and 158F (low-binding) alleles of the activating Fc receptor, CD16A. As a result, margetuximab enhances innate immunity, including CD16A-mediated antibody-dependent cellular cytotoxicity, more effectively than trastuzumab. Margetuximab also potentiates adaptive immunity, including enhanced clonality of the T-cell repertoire and induction of HER2-specific T- and B-cell responses.

In December 2020, margetuximab, in combination with chemotherapy, was approved by the FDA for patients with HER2+ MBC after two or more prior anti-HER2 regimens, at least one of which was for metastatic disease. The approved dose is 15 mg/kg IV every 3 weeks.

The study that led to margetuximab’s approval was the phase 3 SOPHIA trial.
 

SOPHIA trial

SOPHIA was a randomized trial of 536 patients with HER2+ MBC who had received prior treatment with other anti-HER2 therapies, including one to three lines of therapy for MBC.

Patients were randomly assigned 1:1 to receive margetuximab plus chemotherapy or trastuzumab plus chemotherapy. Assignment was stratified by chemotherapy choice (capecitabine, eribulin, gemcitabine, or vinorelbine), the number of previous lines of therapy for MBC, and disease extent.

Co–primary outcome measures were PFS by blinded, independent, central review and OS.

At the second interim analysis, the median PFS was 5.8 months in the margetuximab arm and 4.9 months in the trastuzumab arm (HR, 0.76; 95% CI, 0.59-0.98; P = .033). Results were more impressive in patients with CD16A genotypes containing a 158F allele. In this group, the median PFS was 6.9 months with margetuximab and 5.1 months with trastuzumab (HR, 0.68, 95% CI, 0.52-0.90; P = .005).

At the second interim analysis, the median OS was 21.6 months in the margetuximab arm and 19.8 months in the trastuzumab arm (HR, 0.89; 95% CI, 0.69-1.13; P = .33).

Subgroup data showed no differences in OS between the two arms for any subgroup except HER2+ MBC patients with an IHC score of 2 or higher. This is consistent with the postulated mechanism of action of margetuximab.

The confirmed ORR was 25% in the margetuximab arm and 14% in the trastuzumab arm, with similar durations of response between the study arms.

The most common adverse events in both arms (≥20%), regardless of causality, were fatigue, nausea, diarrhea, and neutropenia. Vomiting was common in the margetuximab arm, and anemia was common in the trastuzumab arm.

Grade 3 or higher adverse events occurred in 53.8% of patients receiving margetuximab and 52.6% of those receiving trastuzumab.

In view of margetuximab’s modest benefits in the SOPHIA trial, the ultimate role for margetuximab in HER2+ MBC may be restricted to patients with the CD16A-158F allele. A neoadjuvant trial is planned in that population.
 

Take-home messages

There are legitimate arguments regarding whether curing MBC is within reach for certain patient subsets, but there is no argument about whether the outlook for patients with HER2+ MBC has improved dramatically in recent years; it has.

The approval of four unique, new agents for the treatment of women with HER2+ MBC in relapse provides further improvements in outcome for these patients and distinctly different opportunities for tailoring treatment to the special circumstances of each patient (e.g., whether brain metastases are present, desire for oral therapy, comorbidities, experience with prior chemotherapy, etc).

When considered along with the potential for incorporating these drugs in earlier settings in well-designed clinical trials, these new drugs offer great promise to a group of patients who faced a dismal outcome just 2 decades ago.

Dr. Lyss was a community-based medical oncologist and clinical researcher for more than 35 years before his recent retirement. His clinical and research interests were focused on breast and lung cancers, as well as expanding clinical trial access to medically underserved populations. He is based in St. Louis. He has no conflicts of interest.

Before 2001, HER2/neu-positive breast cancer (HER2+) was one of the most dreaded diagnoses a woman could face, as treatment was largely ineffective. The discovery of trastuzumab changed that dramatically.

Over the next 20 years, two additional HER2-targeted therapies – lapatinib and trastuzumab emtansine (TDM-1) – earned approval from the Food and Drug Administration for selected patients with early and late HER2+ breast cancer.

Since 2019, four additional HER2-targeted therapies have been approved by the FDA for HER2+ metastatic breast cancer (MBC), changing the treatment paradigm for those patients substantially.

The new agents are especially useful in certain patient populations. The agents offer the promise of improved survival for patients with recurrent metastatic disease and the potential for further reductions in relapse rates in earlier settings.
 

Trastuzumab deruxtecan

Trastuzumab deruxtecan is an antibody-drug conjugate that links three components: an anti-HER2 monoclonal antibody, a highly potent topoisomerase I inhibitor payload, and a tetrapeptide-based cleavable linker.

Trastuzumab deruxtecan has a high drug-to-antibody ratio. A membrane-permeable payload offers the potential for activity against adjacent HER2-negative cells in heterogeneous tumors. It has a long half-life (6 days).

Trastuzumab deruxtecan received accelerated approval from the FDA in December 2019 to treat patients with HER2+ MBC who have received two or more prior HER2-targeted regimens, based on the results of the DESTINY-Breast 01 trial.
 

DESTINY-Breast 01 trial

In the phase 2 DESTINY-Breast 01 trial, 184 patients with a median of six previous treatments received trastuzumab deruxtecan (5.4 mg/kg) intravenously every 21 days. There were 24 patients with treated, asymptomatic brain metastases who participated. Patients with untreated or symptomatic brain metastases were excluded.

Overall, a response to therapy was reported in 112 patients (60.9%), with 6.0% complete and 54.9% partial responses. Most of the patients for whom both baseline and postbaseline data were available had a reduction in tumor size.

The median time until response was 1.6 months, an interval that corresponded to the time until the first scheduled imaging. Three patients (1.6%) had progressive disease, and two patients (1.1%) could not be evaluated.

The median duration of follow-up was 11.1 months, and the median response duration was 14.8 months.

The median progression-free survival (PFS) was 16.4 months, and the median overall survival (OS) was not reached. The median PFS in the patients with brain involvement was 18.1 months.

The most common adverse events of grade 3 or higher were a decreased neutrophil count (20.7%), anemia (8.7%), and nausea (7.6%). Most concerning was that trastuzumab deruxtecan was associated with interstitial lung disease in 13.6% of patients.
 

Tucatinib

Tucatinib is an oral, highly selective HER2 tyrosine kinase inhibitor (TKI). In April 2020, it was approved by the FDA, in combination with trastuzumab and capecitabine, for adult patients with advanced unresectable or metastatic HER2+ breast cancer who have received one or more prior anti-HER2–based regimens for MBC. The approval included patients with brain metastases.

The recommended tucatinib dose is 300 mg orally twice a day in combination with trastuzumab (at the standard dose) and capecitabine (1,000 mg/m² given orally twice daily on days 1-14) on a 21-day cycle, until disease progression or unacceptable toxicity.
 

HER2CLIMB trial

The study that led to the approval of tucatinib was the HER2CLIMB trial. The trial enrolled 612 HER2+ MBC patients who had prior treatment with trastuzumab, pertuzumab, and T-DM1. Patients had received a median of 4 (range, 2-17) prior lines of HER2-targeted therapy.

The patients were randomized 2:1 to receive trastuzumab plus capecitabine and either tucatinib or an identical placebo twice daily.

The primary endpoint was PFS, evaluated in the initial 480 randomized patients. The median PFS was 7.8 months in the tucatinib arm and 5.6 months in the control arm (hazard ratio, 0.54; 95% confidence interval, 0.42-0.71; P < .001).

The confirmed overall response rate for patients with measurable disease was 40.6% in the tucatinib arm and 22.8% in the control arm (P = .001). The proportion of patients still in response at 12 months was 33.1% and 12.3%, respectively.

The median OS was 21.9 months in the tucatinib arm and 17.4 months in the placebo arm (HR, 0.66; 95% CI, 0.50-0.88; P = .005). At 24 months, 44.9% and 26.6% of patients, respectively, were still alive.

The most common grade 3 or higher adverse events (in the tucatinib and placebo arms, respectively) were palmar-plantar erythrodysesthesia syndrome (13.1% vs. 9.1%), diarrhea (12.9% vs. 8.6%), elevations in ALT and AST (approximately 5% vs. 0.5% for each), and fatigue (4.7% vs. 4.1%).
 

Tucatinib in patients with brain involvement

A unique feature of the HER2CLIMB study was that patients with MBC and untreated, symptomatic brain metastases were eligible. Patients with active, untreated central nervous system disease are excluded from virtually all other trials, especially drug-approval trials.

There were 291 patients with brain metastases in HER2CLIMB, 198 (48%) in the tucatinib arm and 93 (46%) in the control arm.

The risk of intracranial progression or death was reduced by 68% in the tucatinib arm (HR, 0.32; 95% CI, 0.22 to 0.48; P  < .0001).

The 1-year CNS-PFS rate was 40.2% in the tucatinib arm and 0% in the placebo arm. The median duration of CNS-PFS was 9.9 months and 4.2 months, respectively.

The risk of death was reduced by 42% in the tucatinib arm (HR, 0.58; 95% CI, 0.40-0.85; P = .005). The median OS was 18.1 months and 12.0 months, respectively.

There were more objective responses in the brain with tucatinib (47.3%) than with placebo (20.0%; P = .03). The median duration of response was 6.8 months and 3.0 months, respectively.

Particularly because of its CNS activity and lack of serious, long-term toxicity, tucatinib combination therapy represents an attractive new option for patients with HER2+ MBC.
 

Neratinib

Neratinib is an irreversible pan-HER TKI that was approved by the FDA in July 2017 for extended adjuvant therapy in patients with early-stage HER2+ breast cancer, following the use of trastuzumab-based therapy.

Long-term results of the ExteNet study led to the approval for use as extended adjuvant therapy.

In February 2020, neratinib was FDA approved in combination with capecitabine for patients with HER2+ MBC after two or more prior anti-HER2–based regimens. The more recent FDA approval was based on results of the NALA trial.
 

NALA trial

The phase 3 NALA trial included 621 patients with HER2+ MBC who had received at least two prior anti-HER2 based regimens.

Patients were randomized 1:1 to receive neratinib at 240 mg orally once daily on days 1-21 with capecitabine at 750 mg/m² orally twice daily on days 1-14 or lapatinib at 1,250 mg orally once daily on days 1-21 with capecitabine at 1,000 mg/m² orally twice daily on days 1-14 for each 21-day cycle. Patients were treated until disease progression or unacceptable toxicity.

The primary endpoints were PFS and OS by blinded, independent, central review.

The median PFS was 5.6 months in the neratinib arm and 5.5 months in the lapatinib arm (HR, 0.76; 95% CI, 0.63-0.93; P = .0059). The PFS rate at 12 months was 28.8% and 14.8%, respectively.

The median OS was 21.0 months in the neratinib arm and 18.7 months in the lapatinib arm (HR, 0.88; 95% CI, 0.72-1.07; P = .2086). The ORR was 32.8% and 26.7%, respectively. The median response duration was 8.5 months and 5.6 months, respectively.

Fewer interventions for CNS disease were required in the neratinib arm than in the lapatinib arm (cumulative incidence, 22.8% vs. 29.2%; P = .043). 

The most frequently reported grade 3-4 adverse reactions for the neratinib combination were diarrhea, nausea, vomiting, fatigue, and decreased appetite.

Grade 3 diarrhea occurred in 24.4% of those in the neratinib arm and 12.5% of those in the lapatinib arm. Antidiarrheal medication was used by 98.3% of patients receiving neratinib and 62.1% of patients receiving lapatinib.
 

Margetuximab-cmkb

Margetuximab is a chimeric Fc-engineered anti-HER2 monoclonal antibody that targets the same epitope as trastuzumab and exerts similar antiproliferative effects.

Compared with trastuzumab, margetuximab has higher affinity for both 158V (high-binding) and 158F (low-binding) alleles of the activating Fc receptor, CD16A. As a result, margetuximab enhances innate immunity, including CD16A-mediated antibody-dependent cellular cytotoxicity, more effectively than trastuzumab. Margetuximab also potentiates adaptive immunity, including enhanced clonality of the T-cell repertoire and induction of HER2-specific T- and B-cell responses.

In December 2020, margetuximab, in combination with chemotherapy, was approved by the FDA for patients with HER2+ MBC after two or more prior anti-HER2 regimens, at least one of which was for metastatic disease. The approved dose is 15 mg/kg IV every 3 weeks.

The study that led to margetuximab’s approval was the phase 3 SOPHIA trial.
 

SOPHIA trial

SOPHIA was a randomized trial of 536 patients with HER2+ MBC who had received prior treatment with other anti-HER2 therapies, including one to three lines of therapy for MBC.

Patients were randomly assigned 1:1 to receive margetuximab plus chemotherapy or trastuzumab plus chemotherapy. Assignment was stratified by chemotherapy choice (capecitabine, eribulin, gemcitabine, or vinorelbine), the number of previous lines of therapy for MBC, and disease extent.

Co–primary outcome measures were PFS by blinded, independent, central review and OS.

At the second interim analysis, the median PFS was 5.8 months in the margetuximab arm and 4.9 months in the trastuzumab arm (HR, 0.76; 95% CI, 0.59-0.98; P = .033). Results were more impressive in patients with CD16A genotypes containing a 158F allele. In this group, the median PFS was 6.9 months with margetuximab and 5.1 months with trastuzumab (HR, 0.68, 95% CI, 0.52-0.90; P = .005).

At the second interim analysis, the median OS was 21.6 months in the margetuximab arm and 19.8 months in the trastuzumab arm (HR, 0.89; 95% CI, 0.69-1.13; P = .33).

Subgroup data showed no differences in OS between the two arms for any subgroup except HER2+ MBC patients with an IHC score of 2 or higher. This is consistent with the postulated mechanism of action of margetuximab.

The confirmed ORR was 25% in the margetuximab arm and 14% in the trastuzumab arm, with similar durations of response between the study arms.

The most common adverse events in both arms (≥20%), regardless of causality, were fatigue, nausea, diarrhea, and neutropenia. Vomiting was common in the margetuximab arm, and anemia was common in the trastuzumab arm.

Grade 3 or higher adverse events occurred in 53.8% of patients receiving margetuximab and 52.6% of those receiving trastuzumab.

In view of margetuximab’s modest benefits in the SOPHIA trial, the ultimate role for margetuximab in HER2+ MBC may be restricted to patients with the CD16A-158F allele. A neoadjuvant trial is planned in that population.
 

Take-home messages

There are legitimate arguments regarding whether curing MBC is within reach for certain patient subsets, but there is no argument about whether the outlook for patients with HER2+ MBC has improved dramatically in recent years; it has.

The approval of four unique, new agents for the treatment of women with HER2+ MBC in relapse provides further improvements in outcome for these patients and distinctly different opportunities for tailoring treatment to the special circumstances of each patient (e.g., whether brain metastases are present, desire for oral therapy, comorbidities, experience with prior chemotherapy, etc).

When considered along with the potential for incorporating these drugs in earlier settings in well-designed clinical trials, these new drugs offer great promise to a group of patients who faced a dismal outcome just 2 decades ago.

Dr. Lyss was a community-based medical oncologist and clinical researcher for more than 35 years before his recent retirement. His clinical and research interests were focused on breast and lung cancers, as well as expanding clinical trial access to medically underserved populations. He is based in St. Louis. He has no conflicts of interest.

The PD-L1 inhibitor atezolizumab (Tecentriq) combined with carboplatin has shown signs of clinical activity in women with metastatic invasive lobular breast cancer (ILC) according to the first results to come from the ongoing GELATO trial.

The 6-month objective response rate was 19%, based on 4 of 21 patients who could be evaluated exhibiting a partial response to the chemoimmunotherapy. A further two (10%) patients had stable disease, meaning that clinical benefit rate was 29%.

GELATO (AssessinG Efficacy of Carboplatin and ATezOlizumab in Metastatic Lobular Breast Cancer) is a phase 2 trial being conducted at four Dutch centers. The primary premise of the study is that “there’s an immune-related subtype of ILC,” researcher Leonie Voorwerk, BSc, reported at the European Society for Medical Oncology: Breast Cancer virtual meeting (Abstract LBA3).

This ILC subtype is “characterized by high expression of immune-related genes and high levels of TILs [tumor-infiltrating lymphocytes] and PDL-1,” said Ms. Voorwerk, a PhD student working with medical oncologist Marleen Kok, MD, PhD, at the Netherlands Cancer Institute in Amsterdam.

Furthermore, she added, in vitro data suggest sensitivity of immune-related-ILCs to platinum and there is preclinical work showing that there is synergy between platinum-based chemotherapy and checkpoint blockade.
 

First chemoimmunotherapy trial in lobular cancer setting

GELATO is a significant trial as it is “the first chemoimmunotherapy trial in metastatic lobular breast cancer,” said Sylvia Adams, MD, professor of medicine and director of the Breast Cancer Center at NYU Langone Health in New York City.

“Of note, the further research should include the immune-related genes and TMB [tumor mutational burden],” proposed Dr. Adams, who was not involved in the trial.

“We should look to tumor mutational burden because while it is not typically high in early disease, metastatic lesions can have higher TMB,” she explained. “Also, metastatic ILC is known to have higher tumor mutational burden compared to IDC [invasive ductal carcinoma], so this is an important thing along with the clinical factors as described in looking at outcomes.”
 

Trial design and patient characteristics

GELATO is a single-arm, nonrandomized trial in which 37 patients with metastatic ILC were screened for inclusion between November 2017 and January 2021. A total of 26 of these patients were registered for the trial, and 23 have so far received at least one cycle of atezolizumab.

Prerequisites for entry into the trial were that patients had to have negative or aberrant E-cadherin, a characteristic feature of ILC. Patients with estrogen receptor (ER)-positive (ER+) disease could be included, but they had to be proven to be resistant to endocrine therapies. No more than two prior lines of palliative chemotherapy were allowed, and all participants had to have lactose dehydrogenase levels of less than 2 times the upper limit of normal.

Patients were then treated with up to 12 cycles of weekly carboplatin (AUC = 1.5 mg/mL/min), with atezolizumab (1,200 mg) added in from cycle 3 onward. Treatment was continued until disease progression or unacceptable toxicity occurred.

“Baseline characteristics were mainly as expected for this patient population,” Ms. Voorwerk stated. Patients were aged 45-89 years, with a median of 60 years. Around half each had a WHO performance status of 0 or 1, and around half each had one to two or three or more metastatic sites; 78% had liver metastases.

“But I want to highlight that we included five patients with the triple-negative ILC,” said Ms. Voorwerk, also highlighting that approximately 50% of patients had received prior palliative chemotherapy. Later in her presentation she noted that four out of the six patients that showed any clinical benefit had triple negative disease.
 

Key findings and next steps

The primary endpoint was progression-free survival (PFS) at 6 months, with secondary endpoints of the best overall response rate, PFS at 1 year, overall survival, and safety.

While details of the latter three endpoints are yet to be reported, Ms. Voorwerk noted that there was a median duration of response of 12 weeks and the median PFS was 15 weeks. The primary endpoint of PFS was met as four patients were free of progression at 6 months and the statistical method used called for patients to be progression free at this time point.

“We observed that stromal TILs and CD8+ cells were not associated with clinical benefits,” said Ms. Voorwerk. There was, however, “a slight trend” toward higher PD-L1 expression in responding patients.

“Further translational research is needed to provide the rationale for new strategies to improve checkpoint blockade in patients with lobular breast cancer,” she concluded.

Dr. Adams concurred, adding that a future research question was whether either atezolizumab or carboplatin was contributing to the response. This is “difficult to tell as the study was a single arm trial.”

Another question, said Dr. Adams, is are “anti-CDK 4/6 inhibitors helpful in improving response rates and durability?” In the trial, 70% of patients had prior exposure to CDK 4/6 inhibitors.

The GELATO trial was sponsored by the Netherlands Cancer Institute with funding from Roche Pharma AG. Ms. Voorwerk had nothing to disclose. Dr. Adams disclosed uncompensated consulting or advisory roles with Bristol-Myers Squibb, Genentech, and Merck from whom she has received research funding. Dr. Adams also disclosed research funding from Amgen, Celgene, and Novartis.

The PD-L1 inhibitor atezolizumab (Tecentriq) combined with carboplatin has shown signs of clinical activity in women with metastatic invasive lobular breast cancer (ILC) according to the first results to come from the ongoing GELATO trial.

The 6-month objective response rate was 19%, based on 4 of 21 patients who could be evaluated exhibiting a partial response to the chemoimmunotherapy. A further two (10%) patients had stable disease, meaning that clinical benefit rate was 29%.

GELATO (AssessinG Efficacy of Carboplatin and ATezOlizumab in Metastatic Lobular Breast Cancer) is a phase 2 trial being conducted at four Dutch centers. The primary premise of the study is that “there’s an immune-related subtype of ILC,” researcher Leonie Voorwerk, BSc, reported at the European Society for Medical Oncology: Breast Cancer virtual meeting (Abstract LBA3).

This ILC subtype is “characterized by high expression of immune-related genes and high levels of TILs [tumor-infiltrating lymphocytes] and PDL-1,” said Ms. Voorwerk, a PhD student working with medical oncologist Marleen Kok, MD, PhD, at the Netherlands Cancer Institute in Amsterdam.

Furthermore, she added, in vitro data suggest sensitivity of immune-related-ILCs to platinum and there is preclinical work showing that there is synergy between platinum-based chemotherapy and checkpoint blockade.
 

First chemoimmunotherapy trial in lobular cancer setting

GELATO is a significant trial as it is “the first chemoimmunotherapy trial in metastatic lobular breast cancer,” said Sylvia Adams, MD, professor of medicine and director of the Breast Cancer Center at NYU Langone Health in New York City.

“Of note, the further research should include the immune-related genes and TMB [tumor mutational burden],” proposed Dr. Adams, who was not involved in the trial.

“We should look to tumor mutational burden because while it is not typically high in early disease, metastatic lesions can have higher TMB,” she explained. “Also, metastatic ILC is known to have higher tumor mutational burden compared to IDC [invasive ductal carcinoma], so this is an important thing along with the clinical factors as described in looking at outcomes.”
 

Trial design and patient characteristics

GELATO is a single-arm, nonrandomized trial in which 37 patients with metastatic ILC were screened for inclusion between November 2017 and January 2021. A total of 26 of these patients were registered for the trial, and 23 have so far received at least one cycle of atezolizumab.

Prerequisites for entry into the trial were that patients had to have negative or aberrant E-cadherin, a characteristic feature of ILC. Patients with estrogen receptor (ER)-positive (ER+) disease could be included, but they had to be proven to be resistant to endocrine therapies. No more than two prior lines of palliative chemotherapy were allowed, and all participants had to have lactose dehydrogenase levels of less than 2 times the upper limit of normal.

Patients were then treated with up to 12 cycles of weekly carboplatin (AUC = 1.5 mg/mL/min), with atezolizumab (1,200 mg) added in from cycle 3 onward. Treatment was continued until disease progression or unacceptable toxicity occurred.

“Baseline characteristics were mainly as expected for this patient population,” Ms. Voorwerk stated. Patients were aged 45-89 years, with a median of 60 years. Around half each had a WHO performance status of 0 or 1, and around half each had one to two or three or more metastatic sites; 78% had liver metastases.

“But I want to highlight that we included five patients with the triple-negative ILC,” said Ms. Voorwerk, also highlighting that approximately 50% of patients had received prior palliative chemotherapy. Later in her presentation she noted that four out of the six patients that showed any clinical benefit had triple negative disease.
 

Key findings and next steps

The primary endpoint was progression-free survival (PFS) at 6 months, with secondary endpoints of the best overall response rate, PFS at 1 year, overall survival, and safety.

While details of the latter three endpoints are yet to be reported, Ms. Voorwerk noted that there was a median duration of response of 12 weeks and the median PFS was 15 weeks. The primary endpoint of PFS was met as four patients were free of progression at 6 months and the statistical method used called for patients to be progression free at this time point.

“We observed that stromal TILs and CD8+ cells were not associated with clinical benefits,” said Ms. Voorwerk. There was, however, “a slight trend” toward higher PD-L1 expression in responding patients.

“Further translational research is needed to provide the rationale for new strategies to improve checkpoint blockade in patients with lobular breast cancer,” she concluded.

Dr. Adams concurred, adding that a future research question was whether either atezolizumab or carboplatin was contributing to the response. This is “difficult to tell as the study was a single arm trial.”

Another question, said Dr. Adams, is are “anti-CDK 4/6 inhibitors helpful in improving response rates and durability?” In the trial, 70% of patients had prior exposure to CDK 4/6 inhibitors.

The GELATO trial was sponsored by the Netherlands Cancer Institute with funding from Roche Pharma AG. Ms. Voorwerk had nothing to disclose. Dr. Adams disclosed uncompensated consulting or advisory roles with Bristol-Myers Squibb, Genentech, and Merck from whom she has received research funding. Dr. Adams also disclosed research funding from Amgen, Celgene, and Novartis.

The PD-L1 inhibitor atezolizumab (Tecentriq) combined with carboplatin has shown signs of clinical activity in women with metastatic invasive lobular breast cancer (ILC) according to the first results to come from the ongoing GELATO trial.

The 6-month objective response rate was 19%, based on 4 of 21 patients who could be evaluated exhibiting a partial response to the chemoimmunotherapy. A further two (10%) patients had stable disease, meaning that clinical benefit rate was 29%.

GELATO (AssessinG Efficacy of Carboplatin and ATezOlizumab in Metastatic Lobular Breast Cancer) is a phase 2 trial being conducted at four Dutch centers. The primary premise of the study is that “there’s an immune-related subtype of ILC,” researcher Leonie Voorwerk, BSc, reported at the European Society for Medical Oncology: Breast Cancer virtual meeting (Abstract LBA3).

This ILC subtype is “characterized by high expression of immune-related genes and high levels of TILs [tumor-infiltrating lymphocytes] and PDL-1,” said Ms. Voorwerk, a PhD student working with medical oncologist Marleen Kok, MD, PhD, at the Netherlands Cancer Institute in Amsterdam.

Furthermore, she added, in vitro data suggest sensitivity of immune-related-ILCs to platinum and there is preclinical work showing that there is synergy between platinum-based chemotherapy and checkpoint blockade.
 

First chemoimmunotherapy trial in lobular cancer setting

GELATO is a significant trial as it is “the first chemoimmunotherapy trial in metastatic lobular breast cancer,” said Sylvia Adams, MD, professor of medicine and director of the Breast Cancer Center at NYU Langone Health in New York City.

“Of note, the further research should include the immune-related genes and TMB [tumor mutational burden],” proposed Dr. Adams, who was not involved in the trial.

“We should look to tumor mutational burden because while it is not typically high in early disease, metastatic lesions can have higher TMB,” she explained. “Also, metastatic ILC is known to have higher tumor mutational burden compared to IDC [invasive ductal carcinoma], so this is an important thing along with the clinical factors as described in looking at outcomes.”
 

Trial design and patient characteristics

GELATO is a single-arm, nonrandomized trial in which 37 patients with metastatic ILC were screened for inclusion between November 2017 and January 2021. A total of 26 of these patients were registered for the trial, and 23 have so far received at least one cycle of atezolizumab.

Prerequisites for entry into the trial were that patients had to have negative or aberrant E-cadherin, a characteristic feature of ILC. Patients with estrogen receptor (ER)-positive (ER+) disease could be included, but they had to be proven to be resistant to endocrine therapies. No more than two prior lines of palliative chemotherapy were allowed, and all participants had to have lactose dehydrogenase levels of less than 2 times the upper limit of normal.

Patients were then treated with up to 12 cycles of weekly carboplatin (AUC = 1.5 mg/mL/min), with atezolizumab (1,200 mg) added in from cycle 3 onward. Treatment was continued until disease progression or unacceptable toxicity occurred.

“Baseline characteristics were mainly as expected for this patient population,” Ms. Voorwerk stated. Patients were aged 45-89 years, with a median of 60 years. Around half each had a WHO performance status of 0 or 1, and around half each had one to two or three or more metastatic sites; 78% had liver metastases.

“But I want to highlight that we included five patients with the triple-negative ILC,” said Ms. Voorwerk, also highlighting that approximately 50% of patients had received prior palliative chemotherapy. Later in her presentation she noted that four out of the six patients that showed any clinical benefit had triple negative disease.
 

Key findings and next steps

The primary endpoint was progression-free survival (PFS) at 6 months, with secondary endpoints of the best overall response rate, PFS at 1 year, overall survival, and safety.

While details of the latter three endpoints are yet to be reported, Ms. Voorwerk noted that there was a median duration of response of 12 weeks and the median PFS was 15 weeks. The primary endpoint of PFS was met as four patients were free of progression at 6 months and the statistical method used called for patients to be progression free at this time point.

“We observed that stromal TILs and CD8+ cells were not associated with clinical benefits,” said Ms. Voorwerk. There was, however, “a slight trend” toward higher PD-L1 expression in responding patients.

“Further translational research is needed to provide the rationale for new strategies to improve checkpoint blockade in patients with lobular breast cancer,” she concluded.

Dr. Adams concurred, adding that a future research question was whether either atezolizumab or carboplatin was contributing to the response. This is “difficult to tell as the study was a single arm trial.”

Another question, said Dr. Adams, is are “anti-CDK 4/6 inhibitors helpful in improving response rates and durability?” In the trial, 70% of patients had prior exposure to CDK 4/6 inhibitors.

The GELATO trial was sponsored by the Netherlands Cancer Institute with funding from Roche Pharma AG. Ms. Voorwerk had nothing to disclose. Dr. Adams disclosed uncompensated consulting or advisory roles with Bristol-Myers Squibb, Genentech, and Merck from whom she has received research funding. Dr. Adams also disclosed research funding from Amgen, Celgene, and Novartis.

Three-year survival rates were similarly high among postmenopausal women with high-risk early luminal breast cancer who were treated with either the neoadjuvant combination of letrozole and palbociclib (Ibrance) or standard neoadjuvant chemotherapy in the phase 2 NeoPAL study.

Progression-free survival (PFS) was a respective 86.7% and 87.2%, with a hazard ratio (HR) of 1.01 (P = .98) comparing the endocrine therapy and cyclin-dependent kinase (CDK) 4/6 inhibitor combination versus FEC/taxane chemotherapy.

There were also no differences between the two treatment arms in terms of invasive disease-free survival (iDFS, HR = 0.83, P = .71) or breast cancer–specific survival (BCSS), although the latter was an exploratory endpoint alongside overall survival (OS).

“The lack of difference is impressive,” said Hope S. Rugo, MD, FASCO, who commented independently on the study’s findings after their presentation at the European Society for Medical Oncology: Breast Cancer virtual meeting.

“Overall survival in patients who received chemotherapy appears to be better, but the very small numbers here make interpretation of this difference impossible,” observed Dr. Rugo, professor of medicine at the University of California San Francisco’s Helen Diller Family Comprehensive Cancer Center.

“Unfortunately, this study is underpowered for definitive conclusions,” acknowledged study investigator Suzette Delaloge, MD, associate professor of medical oncology at Institut Gustave Roussy in Villejuif, France.

However, “it shows that the nonchemotherapy, preoperative letrozole/palbociclib approach deserves further exploration and could be an option for a chemotherapy-free regimen in some specific cases.”
 

Primary data already reported

The NeoPAL study was an open-label, randomized study conducted in 27 centers throughout France that compared the preoperative use of letrozole plus palbociclib to neoadjuvant chemotherapy in 106 postmenopausal patients with either luminal A or B node-positive disease.

Patients were considered for inclusion in the trial if they had been newly diagnosed with estrogen receptor (ER)-positive, HER2-negative stage I-III breast cancer and were not candidates for breast conservation. Genetic testing was used to confirm that only those with luminal B, or luminal A and who were node positive were recruited.

Neoadjuvant treatment consisted of either letrozole (2.5 mg/day) and palbociclib (125 mg daily for 3 weeks out of 4 weeks) for 19 weeks or three 21-day cycles of 5-fluorouracil (500 mg/m²), epirubicin (100 mg/m²), and cyclophosphamide (500 mg/m²), followed by three 21-day cycles of docetaxel (100 mg/m²).

The primary endpoint was the pathological complete response (pCR), defined as a residual cancer burden (RCB) of 0 to 1. Results, which have already been reported, showed equivalent, but perhaps disappointingly low, pathological responses in both the letrozole/palbociclib and chemotherapy arms (3.8% and 5.9%, respectively).

There were, however, identical clinical responses (at around 75%) and “encouraging biomarker responses in the Prosigna-defined high risk luminal breast cancer population,” Dr. Delaloge said.

The NeoPAL findings were on par with those of the CORALLEEN study, Dr. Delaloge suggested. That trial, as Dr. Rugo has also pointed out, was conducted in 106 patients with luminal B early breast cancer and used a combination of letrozole and the CDK 4/6 inhibitor ribociclib (Kisquali).
 

Future studies needed

NeoPAL “is a small study with relatively short follow-up even for hormone receptor-positive, high-risk disease,” Dr. Rugo observed. However, she qualified “this short follow-up can be very meaningful in high-risk disease.” as shown by other CDK 4/6 inhibitor trials.

Dr. Rugo also noted: “Short-term biologic endpoints are clearly more informative following and during neoadjuvant endocrine therapy than pCR and this trial, as well as the data from previous studies, indicates that this is the case.”

Further, Dr. Rugo said: “Antiproliferative response is enhanced with CDK 4/6 inhibitors, but this doesn’t seem to translate into a difference in pCR. The lack of impact on longer term, outcome to date, provides support for ongoing trials.”

Two such trials are already underway. The 200-patient CARABELA trial started recruitment in March last year and is comparing endocrine therapy with letrozole plus the CDK 4/6 inhibitor abemaciclib (Verzenio) to standard chemotherapy in patients with hormone receptor–positive, high-risk Ki67 disease.

Then there is the ADAPTcycle trial, a large open-label, phase 3 trial that is randomizing patients based on Ki67 and recurrence score after a short preoperative induction with endocrine therapy to postoperative chemotherapy or to 2 years of endocrine therapy plus ribociclib, with both arms receiving a standard course of 5 years of endocrine therapy.

“These two studies have provided interesting information that will help us design studies in the future,” said Dr. Rugo.

Not only that, but they will also help “investigate the subgroups of patients that benefit the most from CDK 4/6 inhibitors and better study neoadjuvant endocrine therapy which is an important option for patients that can be evaluated in terms of its efficacy by short term measures of antiproliferative response.”

NeoPAL was sponsored by UNICANCER with funding from Pfizer and NanoString Technologies. Dr. Delaloge disclosed receiving research grants or funding via her institution from Pfizer, AstraZeneca, Roche, Merck, Sanofi, Lilly, Novartis, BMS, Orion, Daiichi, Puma, and Pierre Fabre. Dr. Rugo reported receipt of grants via her institution to perform clinical trials from Pfizer and multiple other companies. She disclosed receiving honoraria from PUMA, Samsung, and Mylan.

Three-year survival rates were similarly high among postmenopausal women with high-risk early luminal breast cancer who were treated with either the neoadjuvant combination of letrozole and palbociclib (Ibrance) or standard neoadjuvant chemotherapy in the phase 2 NeoPAL study.

Progression-free survival (PFS) was a respective 86.7% and 87.2%, with a hazard ratio (HR) of 1.01 (P = .98) comparing the endocrine therapy and cyclin-dependent kinase (CDK) 4/6 inhibitor combination versus FEC/taxane chemotherapy.

There were also no differences between the two treatment arms in terms of invasive disease-free survival (iDFS, HR = 0.83, P = .71) or breast cancer–specific survival (BCSS), although the latter was an exploratory endpoint alongside overall survival (OS).

“The lack of difference is impressive,” said Hope S. Rugo, MD, FASCO, who commented independently on the study’s findings after their presentation at the European Society for Medical Oncology: Breast Cancer virtual meeting.

“Overall survival in patients who received chemotherapy appears to be better, but the very small numbers here make interpretation of this difference impossible,” observed Dr. Rugo, professor of medicine at the University of California San Francisco’s Helen Diller Family Comprehensive Cancer Center.

“Unfortunately, this study is underpowered for definitive conclusions,” acknowledged study investigator Suzette Delaloge, MD, associate professor of medical oncology at Institut Gustave Roussy in Villejuif, France.

However, “it shows that the nonchemotherapy, preoperative letrozole/palbociclib approach deserves further exploration and could be an option for a chemotherapy-free regimen in some specific cases.”
 

Primary data already reported

The NeoPAL study was an open-label, randomized study conducted in 27 centers throughout France that compared the preoperative use of letrozole plus palbociclib to neoadjuvant chemotherapy in 106 postmenopausal patients with either luminal A or B node-positive disease.

Patients were considered for inclusion in the trial if they had been newly diagnosed with estrogen receptor (ER)-positive, HER2-negative stage I-III breast cancer and were not candidates for breast conservation. Genetic testing was used to confirm that only those with luminal B, or luminal A and who were node positive were recruited.

Neoadjuvant treatment consisted of either letrozole (2.5 mg/day) and palbociclib (125 mg daily for 3 weeks out of 4 weeks) for 19 weeks or three 21-day cycles of 5-fluorouracil (500 mg/m²), epirubicin (100 mg/m²), and cyclophosphamide (500 mg/m²), followed by three 21-day cycles of docetaxel (100 mg/m²).

The primary endpoint was the pathological complete response (pCR), defined as a residual cancer burden (RCB) of 0 to 1. Results, which have already been reported, showed equivalent, but perhaps disappointingly low, pathological responses in both the letrozole/palbociclib and chemotherapy arms (3.8% and 5.9%, respectively).

There were, however, identical clinical responses (at around 75%) and “encouraging biomarker responses in the Prosigna-defined high risk luminal breast cancer population,” Dr. Delaloge said.

The NeoPAL findings were on par with those of the CORALLEEN study, Dr. Delaloge suggested. That trial, as Dr. Rugo has also pointed out, was conducted in 106 patients with luminal B early breast cancer and used a combination of letrozole and the CDK 4/6 inhibitor ribociclib (Kisquali).
 

Future studies needed

NeoPAL “is a small study with relatively short follow-up even for hormone receptor-positive, high-risk disease,” Dr. Rugo observed. However, she qualified “this short follow-up can be very meaningful in high-risk disease.” as shown by other CDK 4/6 inhibitor trials.

Dr. Rugo also noted: “Short-term biologic endpoints are clearly more informative following and during neoadjuvant endocrine therapy than pCR and this trial, as well as the data from previous studies, indicates that this is the case.”

Further, Dr. Rugo said: “Antiproliferative response is enhanced with CDK 4/6 inhibitors, but this doesn’t seem to translate into a difference in pCR. The lack of impact on longer term, outcome to date, provides support for ongoing trials.”

Two such trials are already underway. The 200-patient CARABELA trial started recruitment in March last year and is comparing endocrine therapy with letrozole plus the CDK 4/6 inhibitor abemaciclib (Verzenio) to standard chemotherapy in patients with hormone receptor–positive, high-risk Ki67 disease.

Then there is the ADAPTcycle trial, a large open-label, phase 3 trial that is randomizing patients based on Ki67 and recurrence score after a short preoperative induction with endocrine therapy to postoperative chemotherapy or to 2 years of endocrine therapy plus ribociclib, with both arms receiving a standard course of 5 years of endocrine therapy.

“These two studies have provided interesting information that will help us design studies in the future,” said Dr. Rugo.

Not only that, but they will also help “investigate the subgroups of patients that benefit the most from CDK 4/6 inhibitors and better study neoadjuvant endocrine therapy which is an important option for patients that can be evaluated in terms of its efficacy by short term measures of antiproliferative response.”

NeoPAL was sponsored by UNICANCER with funding from Pfizer and NanoString Technologies. Dr. Delaloge disclosed receiving research grants or funding via her institution from Pfizer, AstraZeneca, Roche, Merck, Sanofi, Lilly, Novartis, BMS, Orion, Daiichi, Puma, and Pierre Fabre. Dr. Rugo reported receipt of grants via her institution to perform clinical trials from Pfizer and multiple other companies. She disclosed receiving honoraria from PUMA, Samsung, and Mylan.

Three-year survival rates were similarly high among postmenopausal women with high-risk early luminal breast cancer who were treated with either the neoadjuvant combination of letrozole and palbociclib (Ibrance) or standard neoadjuvant chemotherapy in the phase 2 NeoPAL study.

Progression-free survival (PFS) was a respective 86.7% and 87.2%, with a hazard ratio (HR) of 1.01 (P = .98) comparing the endocrine therapy and cyclin-dependent kinase (CDK) 4/6 inhibitor combination versus FEC/taxane chemotherapy.

There were also no differences between the two treatment arms in terms of invasive disease-free survival (iDFS, HR = 0.83, P = .71) or breast cancer–specific survival (BCSS), although the latter was an exploratory endpoint alongside overall survival (OS).

“The lack of difference is impressive,” said Hope S. Rugo, MD, FASCO, who commented independently on the study’s findings after their presentation at the European Society for Medical Oncology: Breast Cancer virtual meeting.

“Overall survival in patients who received chemotherapy appears to be better, but the very small numbers here make interpretation of this difference impossible,” observed Dr. Rugo, professor of medicine at the University of California San Francisco’s Helen Diller Family Comprehensive Cancer Center.

“Unfortunately, this study is underpowered for definitive conclusions,” acknowledged study investigator Suzette Delaloge, MD, associate professor of medical oncology at Institut Gustave Roussy in Villejuif, France.

However, “it shows that the nonchemotherapy, preoperative letrozole/palbociclib approach deserves further exploration and could be an option for a chemotherapy-free regimen in some specific cases.”
 

Primary data already reported

The NeoPAL study was an open-label, randomized study conducted in 27 centers throughout France that compared the preoperative use of letrozole plus palbociclib to neoadjuvant chemotherapy in 106 postmenopausal patients with either luminal A or B node-positive disease.

Patients were considered for inclusion in the trial if they had been newly diagnosed with estrogen receptor (ER)-positive, HER2-negative stage I-III breast cancer and were not candidates for breast conservation. Genetic testing was used to confirm that only those with luminal B, or luminal A and who were node positive were recruited.

Neoadjuvant treatment consisted of either letrozole (2.5 mg/day) and palbociclib (125 mg daily for 3 weeks out of 4 weeks) for 19 weeks or three 21-day cycles of 5-fluorouracil (500 mg/m²), epirubicin (100 mg/m²), and cyclophosphamide (500 mg/m²), followed by three 21-day cycles of docetaxel (100 mg/m²).

The primary endpoint was the pathological complete response (pCR), defined as a residual cancer burden (RCB) of 0 to 1. Results, which have already been reported, showed equivalent, but perhaps disappointingly low, pathological responses in both the letrozole/palbociclib and chemotherapy arms (3.8% and 5.9%, respectively).

There were, however, identical clinical responses (at around 75%) and “encouraging biomarker responses in the Prosigna-defined high risk luminal breast cancer population,” Dr. Delaloge said.

The NeoPAL findings were on par with those of the CORALLEEN study, Dr. Delaloge suggested. That trial, as Dr. Rugo has also pointed out, was conducted in 106 patients with luminal B early breast cancer and used a combination of letrozole and the CDK 4/6 inhibitor ribociclib (Kisquali).
 

Future studies needed

NeoPAL “is a small study with relatively short follow-up even for hormone receptor-positive, high-risk disease,” Dr. Rugo observed. However, she qualified “this short follow-up can be very meaningful in high-risk disease.” as shown by other CDK 4/6 inhibitor trials.

Dr. Rugo also noted: “Short-term biologic endpoints are clearly more informative following and during neoadjuvant endocrine therapy than pCR and this trial, as well as the data from previous studies, indicates that this is the case.”

Further, Dr. Rugo said: “Antiproliferative response is enhanced with CDK 4/6 inhibitors, but this doesn’t seem to translate into a difference in pCR. The lack of impact on longer term, outcome to date, provides support for ongoing trials.”

Two such trials are already underway. The 200-patient CARABELA trial started recruitment in March last year and is comparing endocrine therapy with letrozole plus the CDK 4/6 inhibitor abemaciclib (Verzenio) to standard chemotherapy in patients with hormone receptor–positive, high-risk Ki67 disease.

Then there is the ADAPTcycle trial, a large open-label, phase 3 trial that is randomizing patients based on Ki67 and recurrence score after a short preoperative induction with endocrine therapy to postoperative chemotherapy or to 2 years of endocrine therapy plus ribociclib, with both arms receiving a standard course of 5 years of endocrine therapy.

“These two studies have provided interesting information that will help us design studies in the future,” said Dr. Rugo.

Not only that, but they will also help “investigate the subgroups of patients that benefit the most from CDK 4/6 inhibitors and better study neoadjuvant endocrine therapy which is an important option for patients that can be evaluated in terms of its efficacy by short term measures of antiproliferative response.”

NeoPAL was sponsored by UNICANCER with funding from Pfizer and NanoString Technologies. Dr. Delaloge disclosed receiving research grants or funding via her institution from Pfizer, AstraZeneca, Roche, Merck, Sanofi, Lilly, Novartis, BMS, Orion, Daiichi, Puma, and Pierre Fabre. Dr. Rugo reported receipt of grants via her institution to perform clinical trials from Pfizer and multiple other companies. She disclosed receiving honoraria from PUMA, Samsung, and Mylan.

Dual HER2 blockade with pertuzumab (Perjeta) and trastuzumab (Herceptin) on top of anthracycline-based neoadjuvant chemotherapy for early-stage breast cancer was associated with a low rate of clinically relevant cardiac events in the final follow-up of the BERENICE study.

After more than 5 years, 1.0%-1.5% of patients who had locally advanced, inflammatory, or early-stage breast cancer developed heart failure, and around 12%-13% showed any significant changes in left ventricular ejection fraction (LVEF).

Importantly, “there were no new safety concerns that arose during long-term follow-up,” study investigator Chau Dang, MD, said in presenting the findings at the European Society for Medical Oncology: Breast Cancer virtual meeting.

Dr. Dang, a medical oncologist at Memorial Sloan Kettering Cancer Centre in New York, reported that the most common cause of death was disease progression.

BERENICE was designed as a cardiac safety study and so not powered to look at long-term efficacy, which Dr. Dang was clear in reporting. Nevertheless event-free survival (EFS), invasive disease-free survival (IDFS), and overall survival (OS) rates at 5 years were all high, at least a respective 89.2%, 91%, and 93.8%, she said. “The medians have not been reached,” she observed.

“These data support the use of dual HER2 blockade with pertuzumab-trastuzumab–based regimens, including in combination with dose-dense, anthracycline-based chemotherapy, across the neoadjuvant and adjuvant treatment settings for the complete treatment of patients with HER2-positive early-stage breast cancer,” Dr. Dang said.

Evandro de Azambuja, MD, PhD, the invited discussant for the trial agreed that the regimens tested appeared “safe from a cardiac standpoint.” However, “you cannot forget that today we are using much less anthracyclines in our patient population.”

Patients in trials are also very different from those treated in clinical practice, often being younger and much fitter, he said. Therefore, it may be important to look at the baseline cardiac medications and comorbidities, Dr. de Azambuja, a medical oncologist at the Institut Jules Bordet in Brussels, Belgium, suggested.

That said, the BERENICE findings sit well with other trials that have been conducted, Dr. de Azambuja pointed out.

“If we look at other trials that have also tested dual HER2 blockade with anthracycline or nonanthracycline regimens, all of them reassure that dual blockade is not more cardiotoxic than single blockade,” he said. This includes trials such as TRYPHAENA, APHINITY, KRISTINE, NeoSphere and PEONY.

The 3-year IDFS rate of 91% in BERENICE also compares well to that seen in APHINITY (94%), Dr. de Azambuja said.
 

BERENICE study design

BERENICE was a multicenter, open-label, nonrandomized and noncomparative phase 2 trial that recruited 400 patients across 75 centers in 12 countries.

Eligibility criteria were that participants had to have been centrally confirmed HER2-positive locally advanced, inflammatory or early breast cancer, with the latter defined as tumors bigger than 2 cm or greater than 5 mm in size, and be node-positive. Patients also had to have a starting LVEF of 55% or higher.

Patients were allocated to one of two neoadjuvant chemotherapy regimens depending on the choice of their physician. One group received a regimen of dose-dense doxorubicin and cyclophosphamide (ddAC) given every 2 weeks for four cycles and then paclitaxel every week for 12 cycles. The other group received 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) every 3 weeks for four cycles and then docetaxel every 3 weeks for four cycles.

Pertuzumab and trastuzumab were started at the same time as the taxanes in both groups and given every 3 weeks for four cycles. Patients then underwent surgery and continued pertuzumab/trastuzumab treatment alone for a further 13 cycles.

The co-primary endpoints were the incidence of New York Heart Association class III or IV heart failure and incidence of symptomatic and asymptomatic LVEF decline of 10% or more.

The primary analysis of the trial was published in 2018 and, at that time, it was reported that three patients in the ddAC cohort and none in the FEC cohort experienced heart failure. LVEF decline was observed in a respective 6.5% and 2% of patients.
 

Discussion points

Dr. de Azambuja noted that the contribution of the chemotherapy to the efficacy cannot be assessed because of the nonrandomized trial design. That should not matter, pointed out Sybille Loibl, MD, PhD, during discussion.

“I think it compares nicely to other trials that looked at dose-dense chemotherapy,” said Dr. Loibl, who is an associate professor at the University of Frankfurt in Germany. “It seems that, in the light of what we consider today probably one of the best anti-HER2 treatments, the chemotherapy is less relevant, and that’s why a dose-dense regimen doesn’t add so much on a standard anthracycline taxane-containing regimen.”

Dr. de Azambuja also commented on the assessment of cardiotoxicity and the use of reduced LVEF as a measure: LVEF decline is a late effect of cardiotoxicity, he observed, and he suggested a different approach in future trials.

“If you use Global Longitudinal Strain, this could be an optimal parameter to detect early subclinical LVEF dysfunction and you should consider it for the next trials looking for cardiac safety. Also, cardiac biomarkers. This was not implemented in this trial, and I strongly recommend this should be for the next trial.”

The BERENICE trial was funded by F. Hoffmann-La Roche. Dr. Dang disclosed receiving consultancy fees from F. Hoffmann-La Roche, Genentech, Daiichi Sankyo, Lilly, and Puma Biotechnology. Dr. de Azambuja was not involved in the study but disclosed receiving honoraria, travel grants, research grants from Roche and Genentech as well as from other companies. Dr. Loibl was one of the cochairs of the session and, among disclosures regarding many other companies, has been an invited speaker for Roche and received reimbursement via her institution for a writing engagement.

Dual HER2 blockade with pertuzumab (Perjeta) and trastuzumab (Herceptin) on top of anthracycline-based neoadjuvant chemotherapy for early-stage breast cancer was associated with a low rate of clinically relevant cardiac events in the final follow-up of the BERENICE study.

After more than 5 years, 1.0%-1.5% of patients who had locally advanced, inflammatory, or early-stage breast cancer developed heart failure, and around 12%-13% showed any significant changes in left ventricular ejection fraction (LVEF).

Importantly, “there were no new safety concerns that arose during long-term follow-up,” study investigator Chau Dang, MD, said in presenting the findings at the European Society for Medical Oncology: Breast Cancer virtual meeting.

Dr. Dang, a medical oncologist at Memorial Sloan Kettering Cancer Centre in New York, reported that the most common cause of death was disease progression.

BERENICE was designed as a cardiac safety study and so not powered to look at long-term efficacy, which Dr. Dang was clear in reporting. Nevertheless event-free survival (EFS), invasive disease-free survival (IDFS), and overall survival (OS) rates at 5 years were all high, at least a respective 89.2%, 91%, and 93.8%, she said. “The medians have not been reached,” she observed.

“These data support the use of dual HER2 blockade with pertuzumab-trastuzumab–based regimens, including in combination with dose-dense, anthracycline-based chemotherapy, across the neoadjuvant and adjuvant treatment settings for the complete treatment of patients with HER2-positive early-stage breast cancer,” Dr. Dang said.

Evandro de Azambuja, MD, PhD, the invited discussant for the trial agreed that the regimens tested appeared “safe from a cardiac standpoint.” However, “you cannot forget that today we are using much less anthracyclines in our patient population.”

Patients in trials are also very different from those treated in clinical practice, often being younger and much fitter, he said. Therefore, it may be important to look at the baseline cardiac medications and comorbidities, Dr. de Azambuja, a medical oncologist at the Institut Jules Bordet in Brussels, Belgium, suggested.

That said, the BERENICE findings sit well with other trials that have been conducted, Dr. de Azambuja pointed out.

“If we look at other trials that have also tested dual HER2 blockade with anthracycline or nonanthracycline regimens, all of them reassure that dual blockade is not more cardiotoxic than single blockade,” he said. This includes trials such as TRYPHAENA, APHINITY, KRISTINE, NeoSphere and PEONY.

The 3-year IDFS rate of 91% in BERENICE also compares well to that seen in APHINITY (94%), Dr. de Azambuja said.
 

BERENICE study design

BERENICE was a multicenter, open-label, nonrandomized and noncomparative phase 2 trial that recruited 400 patients across 75 centers in 12 countries.

Eligibility criteria were that participants had to have been centrally confirmed HER2-positive locally advanced, inflammatory or early breast cancer, with the latter defined as tumors bigger than 2 cm or greater than 5 mm in size, and be node-positive. Patients also had to have a starting LVEF of 55% or higher.

Patients were allocated to one of two neoadjuvant chemotherapy regimens depending on the choice of their physician. One group received a regimen of dose-dense doxorubicin and cyclophosphamide (ddAC) given every 2 weeks for four cycles and then paclitaxel every week for 12 cycles. The other group received 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) every 3 weeks for four cycles and then docetaxel every 3 weeks for four cycles.

Pertuzumab and trastuzumab were started at the same time as the taxanes in both groups and given every 3 weeks for four cycles. Patients then underwent surgery and continued pertuzumab/trastuzumab treatment alone for a further 13 cycles.

The co-primary endpoints were the incidence of New York Heart Association class III or IV heart failure and incidence of symptomatic and asymptomatic LVEF decline of 10% or more.

The primary analysis of the trial was published in 2018 and, at that time, it was reported that three patients in the ddAC cohort and none in the FEC cohort experienced heart failure. LVEF decline was observed in a respective 6.5% and 2% of patients.
 

Discussion points

Dr. de Azambuja noted that the contribution of the chemotherapy to the efficacy cannot be assessed because of the nonrandomized trial design. That should not matter, pointed out Sybille Loibl, MD, PhD, during discussion.

“I think it compares nicely to other trials that looked at dose-dense chemotherapy,” said Dr. Loibl, who is an associate professor at the University of Frankfurt in Germany. “It seems that, in the light of what we consider today probably one of the best anti-HER2 treatments, the chemotherapy is less relevant, and that’s why a dose-dense regimen doesn’t add so much on a standard anthracycline taxane-containing regimen.”

Dr. de Azambuja also commented on the assessment of cardiotoxicity and the use of reduced LVEF as a measure: LVEF decline is a late effect of cardiotoxicity, he observed, and he suggested a different approach in future trials.

“If you use Global Longitudinal Strain, this could be an optimal parameter to detect early subclinical LVEF dysfunction and you should consider it for the next trials looking for cardiac safety. Also, cardiac biomarkers. This was not implemented in this trial, and I strongly recommend this should be for the next trial.”

The BERENICE trial was funded by F. Hoffmann-La Roche. Dr. Dang disclosed receiving consultancy fees from F. Hoffmann-La Roche, Genentech, Daiichi Sankyo, Lilly, and Puma Biotechnology. Dr. de Azambuja was not involved in the study but disclosed receiving honoraria, travel grants, research grants from Roche and Genentech as well as from other companies. Dr. Loibl was one of the cochairs of the session and, among disclosures regarding many other companies, has been an invited speaker for Roche and received reimbursement via her institution for a writing engagement.

Dual HER2 blockade with pertuzumab (Perjeta) and trastuzumab (Herceptin) on top of anthracycline-based neoadjuvant chemotherapy for early-stage breast cancer was associated with a low rate of clinically relevant cardiac events in the final follow-up of the BERENICE study.

After more than 5 years, 1.0%-1.5% of patients who had locally advanced, inflammatory, or early-stage breast cancer developed heart failure, and around 12%-13% showed any significant changes in left ventricular ejection fraction (LVEF).

Importantly, “there were no new safety concerns that arose during long-term follow-up,” study investigator Chau Dang, MD, said in presenting the findings at the European Society for Medical Oncology: Breast Cancer virtual meeting.

Dr. Dang, a medical oncologist at Memorial Sloan Kettering Cancer Centre in New York, reported that the most common cause of death was disease progression.

BERENICE was designed as a cardiac safety study and so not powered to look at long-term efficacy, which Dr. Dang was clear in reporting. Nevertheless event-free survival (EFS), invasive disease-free survival (IDFS), and overall survival (OS) rates at 5 years were all high, at least a respective 89.2%, 91%, and 93.8%, she said. “The medians have not been reached,” she observed.

“These data support the use of dual HER2 blockade with pertuzumab-trastuzumab–based regimens, including in combination with dose-dense, anthracycline-based chemotherapy, across the neoadjuvant and adjuvant treatment settings for the complete treatment of patients with HER2-positive early-stage breast cancer,” Dr. Dang said.

Evandro de Azambuja, MD, PhD, the invited discussant for the trial agreed that the regimens tested appeared “safe from a cardiac standpoint.” However, “you cannot forget that today we are using much less anthracyclines in our patient population.”

Patients in trials are also very different from those treated in clinical practice, often being younger and much fitter, he said. Therefore, it may be important to look at the baseline cardiac medications and comorbidities, Dr. de Azambuja, a medical oncologist at the Institut Jules Bordet in Brussels, Belgium, suggested.

That said, the BERENICE findings sit well with other trials that have been conducted, Dr. de Azambuja pointed out.

“If we look at other trials that have also tested dual HER2 blockade with anthracycline or nonanthracycline regimens, all of them reassure that dual blockade is not more cardiotoxic than single blockade,” he said. This includes trials such as TRYPHAENA, APHINITY, KRISTINE, NeoSphere and PEONY.

The 3-year IDFS rate of 91% in BERENICE also compares well to that seen in APHINITY (94%), Dr. de Azambuja said.
 

BERENICE study design

BERENICE was a multicenter, open-label, nonrandomized and noncomparative phase 2 trial that recruited 400 patients across 75 centers in 12 countries.

Eligibility criteria were that participants had to have been centrally confirmed HER2-positive locally advanced, inflammatory or early breast cancer, with the latter defined as tumors bigger than 2 cm or greater than 5 mm in size, and be node-positive. Patients also had to have a starting LVEF of 55% or higher.

Patients were allocated to one of two neoadjuvant chemotherapy regimens depending on the choice of their physician. One group received a regimen of dose-dense doxorubicin and cyclophosphamide (ddAC) given every 2 weeks for four cycles and then paclitaxel every week for 12 cycles. The other group received 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) every 3 weeks for four cycles and then docetaxel every 3 weeks for four cycles.

Pertuzumab and trastuzumab were started at the same time as the taxanes in both groups and given every 3 weeks for four cycles. Patients then underwent surgery and continued pertuzumab/trastuzumab treatment alone for a further 13 cycles.

The co-primary endpoints were the incidence of New York Heart Association class III or IV heart failure and incidence of symptomatic and asymptomatic LVEF decline of 10% or more.

The primary analysis of the trial was published in 2018 and, at that time, it was reported that three patients in the ddAC cohort and none in the FEC cohort experienced heart failure. LVEF decline was observed in a respective 6.5% and 2% of patients.
 

Discussion points

Dr. de Azambuja noted that the contribution of the chemotherapy to the efficacy cannot be assessed because of the nonrandomized trial design. That should not matter, pointed out Sybille Loibl, MD, PhD, during discussion.

“I think it compares nicely to other trials that looked at dose-dense chemotherapy,” said Dr. Loibl, who is an associate professor at the University of Frankfurt in Germany. “It seems that, in the light of what we consider today probably one of the best anti-HER2 treatments, the chemotherapy is less relevant, and that’s why a dose-dense regimen doesn’t add so much on a standard anthracycline taxane-containing regimen.”

Dr. de Azambuja also commented on the assessment of cardiotoxicity and the use of reduced LVEF as a measure: LVEF decline is a late effect of cardiotoxicity, he observed, and he suggested a different approach in future trials.

“If you use Global Longitudinal Strain, this could be an optimal parameter to detect early subclinical LVEF dysfunction and you should consider it for the next trials looking for cardiac safety. Also, cardiac biomarkers. This was not implemented in this trial, and I strongly recommend this should be for the next trial.”

The BERENICE trial was funded by F. Hoffmann-La Roche. Dr. Dang disclosed receiving consultancy fees from F. Hoffmann-La Roche, Genentech, Daiichi Sankyo, Lilly, and Puma Biotechnology. Dr. de Azambuja was not involved in the study but disclosed receiving honoraria, travel grants, research grants from Roche and Genentech as well as from other companies. Dr. Loibl was one of the cochairs of the session and, among disclosures regarding many other companies, has been an invited speaker for Roche and received reimbursement via her institution for a writing engagement.

The number of women seeking care from the Veterans Health Administration (VHA) is increasing.¹ In 2015, there were 2 million women veterans in the United States, which is 9.4% of the total veteran population. This group is expected to increase at an average of about 18,000 women per year for the next 10 years.² The percentage of women veterans who are US Department of Veterans Affairs (VA) users aged 45 to 64 years rose 46% from 2000 to 2015.^1,3-4 It is estimated that 15% of veterans who used VA services in 2020 were women.¹ Nineteen percent of women veterans are Black.¹ The median age of women veterans in 2015 was 50 years.⁵ Breast cancer is the leading cancer affecting female veterans, and data suggest they have an increased risk of breast cancer based on unique service-related exposures.^1,6-9

In the US, about 10 million women are eligible for breast cancer preventive therapy, including, but not limited to, medications, surgery, or lifestyle changes.¹⁰ Secondary prevention options include change in surveillance that can reduce their risk or identify cancer at an earlier stage when treatment is more effective. The United States Preventive Services Task Force, the National Comprehensive Cancer Network, the American Society for Clinical Oncology, the National Institute for Health and Care Excellence, and the Oncology Nursing Society recommend screening women aged ≥ 35 years to assess breast cancer risk.^11-18 If a woman is at increased risk, she may be a candidate for chemoprevention, prozphylactic surgery, and possibly an enhanced screening regimen.

Urban and minority women are an understudied population. Most veterans (75%) live in urban or suburban settings.^19,20 Urban veteran women constitute an important potential study population.

Chemoprevention measures have been underused because of factors involving both women and their health care providers. A large proportion of women are unaware of their higher risk status due to lack of adequate screening and risk assessment.^21,22 In addition to patient lack of awareness of their high-risk status, primary care physicians are also reluctant to prescribe chemopreventive agents due to a lack of comfort or familiarity with the risks and benefits.^23-26 The STAR2015, BCPT2005, IBIS2014, MAP3 2011, IBIS-I 2014, and IBIS II 2014 studies clearly demonstrate a 49 to 62% reduction in risk for women using chemoprevention such as selective estrogen receptor modulators or aromatase inhibitors, respectively.^27-32 Yet only 4 to 9% of high-risk women not enrolled in a clinical trial are using chemoprevention.^33-39

The possibility of developing breast cancer also may be increased because of a positive family history or being a member of a family in which there is a known susceptibility gene mutation.⁴⁰ Based on these risk factors, women may be eligible for tailored follow-up and genetic counseling.^41-44

Nationally, 7 to 10% of the civilian US population will experience posttraumatic stress disorder (PTSD).⁴⁵ The rates are remarkably higher for women veterans, with roughly 20% diagnosed with PTSD.^46,47 Anxiety and PTSD have been implicated in poor adherence to medical advice.^48,49

In 2014, a national VA multidisciplinary group focused on breast cancer prevention, detection, treatment, and research to address breast health in the growing population of women veterans. High-risk breast cancer screenings are not routinely carried out by the VA in primary care, women’s health, or oncology services. Furthermore, the recording of screening questionnaire results was not synchronized until a standard questionnaire was created and approved as a template by this group in the VA electronic medical record (EMR) in 2015.

Several prediction models can identify which women are at an increased risk of developing breast cancer. The most commonly used risk assessment model, the Gail breast cancer risk assessment tool (BCRAT), has been refined to include women of additional ethnicities (https://www.cancer.gov/bcrisktool).

This pilot project was launched to identify an effective manner to screen women veterans regarding their risk of developing breast cancer and refer them for chemoprevention education or genetic counseling as appropriate.

Methods

A high-risk breast cancer screening questionnaire based on the Gail BCRAT and including lifestyle questions was developed and included as a note template in the VA EMR. The James J. Peters VA Medical Center, Bronx, NY (JJPVAMC) and the Washington DC VA Medical Center (DCVAMC) ran a pilot study between 2015 and 2018 using this breast cancer screening questionnaire to collect data from women veterans. Quality Executive Committee and institutional review board approvals were granted respectively.

Eligibility criteria included women aged ≥ 35 years with no personal history of breast cancer. Most patients were self-referred, but participants also were recruited during VA Breast Cancer Awareness month events, health fairs, or at informational tables in the hospital lobbies. After completing the 20 multiple choice questionnaire with a study team member, either in person or over the phone, a 5-year and lifetime risk of invasive breast cancer was calculated using the Gail BCRAT. A woman is considered high risk and eligible for chemoprevention if her 5-year risk is > 1.66% or her lifetime risk is ≥ 20%. Eligibility for genetic counseling is based on the Breast Cancer Referral Screening Tool, which includes a personal or family history of breast or ovarian cancer and Jewish ancestry.

All patients were notified of their average or high risk status by a clinician. Those who were deemed to be average risk received a follow-up letter in the mail with instructions (eg, to follow-up with a yearly mammogram). Those who were deemed to be high risk for developing breast cancer were asked to come in for an appointment with the study principal investigator (a VA oncologist/breast cancer specialist) to discuss prevention options, further screening, or referrals to genetic counseling. Depending on a patient’s other health factors, a woman at high risk for developing breast cancer also may be a candidate for chemoprevention with tamoxifen, raloxifene, exemestane, anastrozole, or letrozole.

Data on the participant’s lifestyle, including exercise, diet, and smoking, were evaluated to determine whether these factors had an impact on risk status.

Results

The JJP and DC VAMCs screened 103 women veterans between 2015 and 2018. Four patients were excluded for nonveteran (spousal) status, leaving 99 women veterans with a mean age of 54 years. The most common self-reported races were Black (60%), non-Hispanic White (14%), and Hispanic or Latino (13%) (Table 1).

Women veterans in our study were nearly 3-times more likely than the general population were to receive a high-risk Gail Score/BCRAT (35% vs 13%, respectively).^50,51 Of this subset, 46% had breast biopsies, and 86% had a positive family history. Thirty-one percent of Black women in our study were high risk, while nationally, 8.2 to 13.3% of Black women aged 50 to 59 years are considered high risk.^50,51 Of the Black high-risk group with a high Gail/BCRAT score, 94% had a positive family history, and 33% had a history of breast biopsy (Table 2).

Of the 35 high-risk patients 26 (74%) patients accepted consultations for chemoprevention and 5 (19%) started chemoprevention. Of this high-risk group, 13 (37%) patients were referred for genetic counseling (Table 3).⁴⁴ The prevalence of PTSD was present in 31% of high-risk women and 29% of the cohort (Figure).The lifestyle questions indicated that, among all participants, 79% had an overweight or obese body mass index; 58% exercised weekly; 51% consumed alcohol; 14% were smokers; and 21% consumed 3 to 4 servings of fruits/vegetables daily.

Discussion

Breast cancer is the most common cancer in women.⁵² The number of women with breast cancer in the VHA has more than tripled from 1995 to 2012.¹ The lifetime risk of developing breast cancer in the general population is about 13%.⁵⁰ This rate can be affected by risk factors including age, hormone exposure, family history, radiation exposure, and lifestyle factors, such as weight and alcohol use.^6,52-56 In the United States, invasive breast cancer affects 1 in 8 women.^50,52,57

Our screened population showed nearly 3 times as many women veterans were at an increased risk for breast cancer when compared with historical averages in US women. This difference may be based on a high rate of prior breast biopsies or positive family history, although a provocative study using the Surveillance, Epidemiology, and End Results database showed military women to have higher rates of breast cancer as well.⁹ Historically, Blacks are vastly understudied in clinical research with only 5% representation on a national level.^5,58 The urban locations of both pilot sites (Washington, DC and Bronx, NY) allowed for the inclusion of minority patients in our study. We found that the rates of breast cancer in Black women veterans to be higher than seen nationally, possibly prompting further screening initiatives for this understudied population.

Our pilot study’s chemoprevention utilization (19%) was double the < 10% seen in the national population.^33-35 The presence of a knowledgeable breast health practitioner to recruit study participants and offer personalized counseling to women veterans is a likely factor in overcoming barriers to chemopreventive acceptance. These participants may have been motivated to seek care for their high-risk status given a strong family history and prior breast biopsies.

Interestingly, a 3-fold higher PTSD rate was seen in this pilot population (29%) when compared with PTSD rates in the general female population (7-10%) and still one-third higher than the general population of women veterans (20%).^45-47 Mental health, anxiety, and PTSD have been barriers to patients who sought treatment and have been implicated in poor adherence to medical advice.^48,49 Cancer screening can induce anxiety in patients, and it may be amplified in patients with PTSD. It was remarkable that although adherence with screening recommendations is decreased when PTSD is present, our patient population demonstrated a higher rate of screening adherence.

Women who are seen at the VA often use multiple clinical specialties, and their EMR can be accessed across VA medical centers nationwide. Therefore, identifying women veterans who meet screening criteria is easily attainable within the VA.

When comparing high-risk with average risk women, the lifestyle results (BMI, smoking history, exercise and consumption of fruits, vegetables and alcohol) were essentially the same. Lifestyle factors were similar to national population rates and were unlikely to impact risk levels.

Limitations

Study limitations included a high number of self-referrals and the large percentage of patients with a family history of breast cancer, making them more likely to seek screening. The higher-than-average risk of breast cancer may be driven by a high rate of breast biopsies and a strong family history. Lifestyle metrics could not be accurately compared to other national assessments of lifestyle factors due to the difference in data points that we used or the format of our questions.

Conclusions

As the number of women veterans increases and the incidence of breast cancer in women veterans rise, chemoprevention options should follow national guidelines. To our knowledge, this is the only oncology study with 60% Black women veterans. This study had a higher participation rate for Black women veterans than is typically seen in national research studies and shows the VA to be a germane source for further understanding of an understudied population that may benefit from increased screening for breast cancer.

A team-based, multidisciplinary model that meets the unique healthcare needs of women veterans results in a patient-centric delivery of care for assessing breast cancer risk status and prevention options. This model can be replicated nationally by directing primary care physicians and women’s health practitioners to a risk-assessment questionnaire and referring high-risk women for appropriate preventative care. Given that these results show chemoprevention adherence rates doubled those seen nationally, perhaps techniques used within this VA pilot study may be adapted to decrease breast cancer incidence nationally.

Since the rate of PTSD among women veterans is triple the national average, we would expect adherence rates to be lower in our patient cohort. However, the multidisciplinary approach we used in this study (eg, 1:1 consultation with oncologist; genetic counseling referrals; mental health support available), may have improved adherence rates. Perhaps the high rates of PTSD seen in the VA patient population can be a useful way to explore patient adherence rates in those with mental illness and medical conditions.

Future research with a larger cohort may lead to greater insight into the correlation between PTSD and adherence to treatment. Exploring the connection between breast cancer, epigenetics, and specific military service-related exposures could be an area of analysis among this veteran population exhibiting increased breast cancer rates. VAMCs are situated in rural, suburban, and urban locations across the United States and offers a diverse socioeconomic and ethnic patient population for inclusion in clinical investigations. Women veterans make up a small subpopulation of women in the United States, but it is worth considering VA patients as an untapped resource for research collaboration.

Acknowledgements

The authors thank Steven Sanchez and Marissa Vallette, PhD, Breast Health Research Group. This research project was approved by the James J. Peters VA Medical Center Quality Executive Committee and the Washington, DC VA Medical Center Institutional Review Board. This work was supported by the US Department of Veterans Affairs. This work did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Author disclosures

The authors report no actual or potential conflicts of interest with regard to this article.

Disclaimer

The opinions expressed herein are those of the authors and do not necessarily reflect those of Federal Practitioner, Frontline Medical Communications Inc., the US Government, or any of its agencies.

The number of women seeking care from the Veterans Health Administration (VHA) is increasing.¹ In 2015, there were 2 million women veterans in the United States, which is 9.4% of the total veteran population. This group is expected to increase at an average of about 18,000 women per year for the next 10 years.² The percentage of women veterans who are US Department of Veterans Affairs (VA) users aged 45 to 64 years rose 46% from 2000 to 2015.^1,3-4 It is estimated that 15% of veterans who used VA services in 2020 were women.¹ Nineteen percent of women veterans are Black.¹ The median age of women veterans in 2015 was 50 years.⁵ Breast cancer is the leading cancer affecting female veterans, and data suggest they have an increased risk of breast cancer based on unique service-related exposures.^1,6-9

In the US, about 10 million women are eligible for breast cancer preventive therapy, including, but not limited to, medications, surgery, or lifestyle changes.¹⁰ Secondary prevention options include change in surveillance that can reduce their risk or identify cancer at an earlier stage when treatment is more effective. The United States Preventive Services Task Force, the National Comprehensive Cancer Network, the American Society for Clinical Oncology, the National Institute for Health and Care Excellence, and the Oncology Nursing Society recommend screening women aged ≥ 35 years to assess breast cancer risk.^11-18 If a woman is at increased risk, she may be a candidate for chemoprevention, prozphylactic surgery, and possibly an enhanced screening regimen.

Urban and minority women are an understudied population. Most veterans (75%) live in urban or suburban settings.^19,20 Urban veteran women constitute an important potential study population.

Chemoprevention measures have been underused because of factors involving both women and their health care providers. A large proportion of women are unaware of their higher risk status due to lack of adequate screening and risk assessment.^21,22 In addition to patient lack of awareness of their high-risk status, primary care physicians are also reluctant to prescribe chemopreventive agents due to a lack of comfort or familiarity with the risks and benefits.^23-26 The STAR2015, BCPT2005, IBIS2014, MAP3 2011, IBIS-I 2014, and IBIS II 2014 studies clearly demonstrate a 49 to 62% reduction in risk for women using chemoprevention such as selective estrogen receptor modulators or aromatase inhibitors, respectively.^27-32 Yet only 4 to 9% of high-risk women not enrolled in a clinical trial are using chemoprevention.^33-39

The possibility of developing breast cancer also may be increased because of a positive family history or being a member of a family in which there is a known susceptibility gene mutation.⁴⁰ Based on these risk factors, women may be eligible for tailored follow-up and genetic counseling.^41-44

Nationally, 7 to 10% of the civilian US population will experience posttraumatic stress disorder (PTSD).⁴⁵ The rates are remarkably higher for women veterans, with roughly 20% diagnosed with PTSD.^46,47 Anxiety and PTSD have been implicated in poor adherence to medical advice.^48,49

In 2014, a national VA multidisciplinary group focused on breast cancer prevention, detection, treatment, and research to address breast health in the growing population of women veterans. High-risk breast cancer screenings are not routinely carried out by the VA in primary care, women’s health, or oncology services. Furthermore, the recording of screening questionnaire results was not synchronized until a standard questionnaire was created and approved as a template by this group in the VA electronic medical record (EMR) in 2015.

Several prediction models can identify which women are at an increased risk of developing breast cancer. The most commonly used risk assessment model, the Gail breast cancer risk assessment tool (BCRAT), has been refined to include women of additional ethnicities (https://www.cancer.gov/bcrisktool).

This pilot project was launched to identify an effective manner to screen women veterans regarding their risk of developing breast cancer and refer them for chemoprevention education or genetic counseling as appropriate.

Methods

A high-risk breast cancer screening questionnaire based on the Gail BCRAT and including lifestyle questions was developed and included as a note template in the VA EMR. The James J. Peters VA Medical Center, Bronx, NY (JJPVAMC) and the Washington DC VA Medical Center (DCVAMC) ran a pilot study between 2015 and 2018 using this breast cancer screening questionnaire to collect data from women veterans. Quality Executive Committee and institutional review board approvals were granted respectively.

Eligibility criteria included women aged ≥ 35 years with no personal history of breast cancer. Most patients were self-referred, but participants also were recruited during VA Breast Cancer Awareness month events, health fairs, or at informational tables in the hospital lobbies. After completing the 20 multiple choice questionnaire with a study team member, either in person or over the phone, a 5-year and lifetime risk of invasive breast cancer was calculated using the Gail BCRAT. A woman is considered high risk and eligible for chemoprevention if her 5-year risk is > 1.66% or her lifetime risk is ≥ 20%. Eligibility for genetic counseling is based on the Breast Cancer Referral Screening Tool, which includes a personal or family history of breast or ovarian cancer and Jewish ancestry.

All patients were notified of their average or high risk status by a clinician. Those who were deemed to be average risk received a follow-up letter in the mail with instructions (eg, to follow-up with a yearly mammogram). Those who were deemed to be high risk for developing breast cancer were asked to come in for an appointment with the study principal investigator (a VA oncologist/breast cancer specialist) to discuss prevention options, further screening, or referrals to genetic counseling. Depending on a patient’s other health factors, a woman at high risk for developing breast cancer also may be a candidate for chemoprevention with tamoxifen, raloxifene, exemestane, anastrozole, or letrozole.

Data on the participant’s lifestyle, including exercise, diet, and smoking, were evaluated to determine whether these factors had an impact on risk status.

Results

The JJP and DC VAMCs screened 103 women veterans between 2015 and 2018. Four patients were excluded for nonveteran (spousal) status, leaving 99 women veterans with a mean age of 54 years. The most common self-reported races were Black (60%), non-Hispanic White (14%), and Hispanic or Latino (13%) (Table 1).

Women veterans in our study were nearly 3-times more likely than the general population were to receive a high-risk Gail Score/BCRAT (35% vs 13%, respectively).^50,51 Of this subset, 46% had breast biopsies, and 86% had a positive family history. Thirty-one percent of Black women in our study were high risk, while nationally, 8.2 to 13.3% of Black women aged 50 to 59 years are considered high risk.^50,51 Of the Black high-risk group with a high Gail/BCRAT score, 94% had a positive family history, and 33% had a history of breast biopsy (Table 2).

Of the 35 high-risk patients 26 (74%) patients accepted consultations for chemoprevention and 5 (19%) started chemoprevention. Of this high-risk group, 13 (37%) patients were referred for genetic counseling (Table 3).⁴⁴ The prevalence of PTSD was present in 31% of high-risk women and 29% of the cohort (Figure).The lifestyle questions indicated that, among all participants, 79% had an overweight or obese body mass index; 58% exercised weekly; 51% consumed alcohol; 14% were smokers; and 21% consumed 3 to 4 servings of fruits/vegetables daily.

Discussion

Breast cancer is the most common cancer in women.⁵² The number of women with breast cancer in the VHA has more than tripled from 1995 to 2012.¹ The lifetime risk of developing breast cancer in the general population is about 13%.⁵⁰ This rate can be affected by risk factors including age, hormone exposure, family history, radiation exposure, and lifestyle factors, such as weight and alcohol use.^6,52-56 In the United States, invasive breast cancer affects 1 in 8 women.^50,52,57

Our screened population showed nearly 3 times as many women veterans were at an increased risk for breast cancer when compared with historical averages in US women. This difference may be based on a high rate of prior breast biopsies or positive family history, although a provocative study using the Surveillance, Epidemiology, and End Results database showed military women to have higher rates of breast cancer as well.⁹ Historically, Blacks are vastly understudied in clinical research with only 5% representation on a national level.^5,58 The urban locations of both pilot sites (Washington, DC and Bronx, NY) allowed for the inclusion of minority patients in our study. We found that the rates of breast cancer in Black women veterans to be higher than seen nationally, possibly prompting further screening initiatives for this understudied population.

Our pilot study’s chemoprevention utilization (19%) was double the < 10% seen in the national population.^33-35 The presence of a knowledgeable breast health practitioner to recruit study participants and offer personalized counseling to women veterans is a likely factor in overcoming barriers to chemopreventive acceptance. These participants may have been motivated to seek care for their high-risk status given a strong family history and prior breast biopsies.

Interestingly, a 3-fold higher PTSD rate was seen in this pilot population (29%) when compared with PTSD rates in the general female population (7-10%) and still one-third higher than the general population of women veterans (20%).^45-47 Mental health, anxiety, and PTSD have been barriers to patients who sought treatment and have been implicated in poor adherence to medical advice.^48,49 Cancer screening can induce anxiety in patients, and it may be amplified in patients with PTSD. It was remarkable that although adherence with screening recommendations is decreased when PTSD is present, our patient population demonstrated a higher rate of screening adherence.

Women who are seen at the VA often use multiple clinical specialties, and their EMR can be accessed across VA medical centers nationwide. Therefore, identifying women veterans who meet screening criteria is easily attainable within the VA.

When comparing high-risk with average risk women, the lifestyle results (BMI, smoking history, exercise and consumption of fruits, vegetables and alcohol) were essentially the same. Lifestyle factors were similar to national population rates and were unlikely to impact risk levels.

Limitations

Study limitations included a high number of self-referrals and the large percentage of patients with a family history of breast cancer, making them more likely to seek screening. The higher-than-average risk of breast cancer may be driven by a high rate of breast biopsies and a strong family history. Lifestyle metrics could not be accurately compared to other national assessments of lifestyle factors due to the difference in data points that we used or the format of our questions.

Conclusions

As the number of women veterans increases and the incidence of breast cancer in women veterans rise, chemoprevention options should follow national guidelines. To our knowledge, this is the only oncology study with 60% Black women veterans. This study had a higher participation rate for Black women veterans than is typically seen in national research studies and shows the VA to be a germane source for further understanding of an understudied population that may benefit from increased screening for breast cancer.

A team-based, multidisciplinary model that meets the unique healthcare needs of women veterans results in a patient-centric delivery of care for assessing breast cancer risk status and prevention options. This model can be replicated nationally by directing primary care physicians and women’s health practitioners to a risk-assessment questionnaire and referring high-risk women for appropriate preventative care. Given that these results show chemoprevention adherence rates doubled those seen nationally, perhaps techniques used within this VA pilot study may be adapted to decrease breast cancer incidence nationally.

Since the rate of PTSD among women veterans is triple the national average, we would expect adherence rates to be lower in our patient cohort. However, the multidisciplinary approach we used in this study (eg, 1:1 consultation with oncologist; genetic counseling referrals; mental health support available), may have improved adherence rates. Perhaps the high rates of PTSD seen in the VA patient population can be a useful way to explore patient adherence rates in those with mental illness and medical conditions.

Future research with a larger cohort may lead to greater insight into the correlation between PTSD and adherence to treatment. Exploring the connection between breast cancer, epigenetics, and specific military service-related exposures could be an area of analysis among this veteran population exhibiting increased breast cancer rates. VAMCs are situated in rural, suburban, and urban locations across the United States and offers a diverse socioeconomic and ethnic patient population for inclusion in clinical investigations. Women veterans make up a small subpopulation of women in the United States, but it is worth considering VA patients as an untapped resource for research collaboration.

Acknowledgements

The authors thank Steven Sanchez and Marissa Vallette, PhD, Breast Health Research Group. This research project was approved by the James J. Peters VA Medical Center Quality Executive Committee and the Washington, DC VA Medical Center Institutional Review Board. This work was supported by the US Department of Veterans Affairs. This work did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Author disclosures

The authors report no actual or potential conflicts of interest with regard to this article.

Disclaimer

The opinions expressed herein are those of the authors and do not necessarily reflect those of Federal Practitioner, Frontline Medical Communications Inc., the US Government, or any of its agencies.

The number of women seeking care from the Veterans Health Administration (VHA) is increasing.¹ In 2015, there were 2 million women veterans in the United States, which is 9.4% of the total veteran population. This group is expected to increase at an average of about 18,000 women per year for the next 10 years.² The percentage of women veterans who are US Department of Veterans Affairs (VA) users aged 45 to 64 years rose 46% from 2000 to 2015.^1,3-4 It is estimated that 15% of veterans who used VA services in 2020 were women.¹ Nineteen percent of women veterans are Black.¹ The median age of women veterans in 2015 was 50 years.⁵ Breast cancer is the leading cancer affecting female veterans, and data suggest they have an increased risk of breast cancer based on unique service-related exposures.^1,6-9

In the US, about 10 million women are eligible for breast cancer preventive therapy, including, but not limited to, medications, surgery, or lifestyle changes.¹⁰ Secondary prevention options include change in surveillance that can reduce their risk or identify cancer at an earlier stage when treatment is more effective. The United States Preventive Services Task Force, the National Comprehensive Cancer Network, the American Society for Clinical Oncology, the National Institute for Health and Care Excellence, and the Oncology Nursing Society recommend screening women aged ≥ 35 years to assess breast cancer risk.^11-18 If a woman is at increased risk, she may be a candidate for chemoprevention, prozphylactic surgery, and possibly an enhanced screening regimen.

Urban and minority women are an understudied population. Most veterans (75%) live in urban or suburban settings.^19,20 Urban veteran women constitute an important potential study population.

Chemoprevention measures have been underused because of factors involving both women and their health care providers. A large proportion of women are unaware of their higher risk status due to lack of adequate screening and risk assessment.^21,22 In addition to patient lack of awareness of their high-risk status, primary care physicians are also reluctant to prescribe chemopreventive agents due to a lack of comfort or familiarity with the risks and benefits.^23-26 The STAR2015, BCPT2005, IBIS2014, MAP3 2011, IBIS-I 2014, and IBIS II 2014 studies clearly demonstrate a 49 to 62% reduction in risk for women using chemoprevention such as selective estrogen receptor modulators or aromatase inhibitors, respectively.^27-32 Yet only 4 to 9% of high-risk women not enrolled in a clinical trial are using chemoprevention.^33-39

The possibility of developing breast cancer also may be increased because of a positive family history or being a member of a family in which there is a known susceptibility gene mutation.⁴⁰ Based on these risk factors, women may be eligible for tailored follow-up and genetic counseling.^41-44

Nationally, 7 to 10% of the civilian US population will experience posttraumatic stress disorder (PTSD).⁴⁵ The rates are remarkably higher for women veterans, with roughly 20% diagnosed with PTSD.^46,47 Anxiety and PTSD have been implicated in poor adherence to medical advice.^48,49

In 2014, a national VA multidisciplinary group focused on breast cancer prevention, detection, treatment, and research to address breast health in the growing population of women veterans. High-risk breast cancer screenings are not routinely carried out by the VA in primary care, women’s health, or oncology services. Furthermore, the recording of screening questionnaire results was not synchronized until a standard questionnaire was created and approved as a template by this group in the VA electronic medical record (EMR) in 2015.

Several prediction models can identify which women are at an increased risk of developing breast cancer. The most commonly used risk assessment model, the Gail breast cancer risk assessment tool (BCRAT), has been refined to include women of additional ethnicities (https://www.cancer.gov/bcrisktool).

This pilot project was launched to identify an effective manner to screen women veterans regarding their risk of developing breast cancer and refer them for chemoprevention education or genetic counseling as appropriate.

Methods

A high-risk breast cancer screening questionnaire based on the Gail BCRAT and including lifestyle questions was developed and included as a note template in the VA EMR. The James J. Peters VA Medical Center, Bronx, NY (JJPVAMC) and the Washington DC VA Medical Center (DCVAMC) ran a pilot study between 2015 and 2018 using this breast cancer screening questionnaire to collect data from women veterans. Quality Executive Committee and institutional review board approvals were granted respectively.

Eligibility criteria included women aged ≥ 35 years with no personal history of breast cancer. Most patients were self-referred, but participants also were recruited during VA Breast Cancer Awareness month events, health fairs, or at informational tables in the hospital lobbies. After completing the 20 multiple choice questionnaire with a study team member, either in person or over the phone, a 5-year and lifetime risk of invasive breast cancer was calculated using the Gail BCRAT. A woman is considered high risk and eligible for chemoprevention if her 5-year risk is > 1.66% or her lifetime risk is ≥ 20%. Eligibility for genetic counseling is based on the Breast Cancer Referral Screening Tool, which includes a personal or family history of breast or ovarian cancer and Jewish ancestry.

All patients were notified of their average or high risk status by a clinician. Those who were deemed to be average risk received a follow-up letter in the mail with instructions (eg, to follow-up with a yearly mammogram). Those who were deemed to be high risk for developing breast cancer were asked to come in for an appointment with the study principal investigator (a VA oncologist/breast cancer specialist) to discuss prevention options, further screening, or referrals to genetic counseling. Depending on a patient’s other health factors, a woman at high risk for developing breast cancer also may be a candidate for chemoprevention with tamoxifen, raloxifene, exemestane, anastrozole, or letrozole.

Data on the participant’s lifestyle, including exercise, diet, and smoking, were evaluated to determine whether these factors had an impact on risk status.

Results

The JJP and DC VAMCs screened 103 women veterans between 2015 and 2018. Four patients were excluded for nonveteran (spousal) status, leaving 99 women veterans with a mean age of 54 years. The most common self-reported races were Black (60%), non-Hispanic White (14%), and Hispanic or Latino (13%) (Table 1).

Women veterans in our study were nearly 3-times more likely than the general population were to receive a high-risk Gail Score/BCRAT (35% vs 13%, respectively).^50,51 Of this subset, 46% had breast biopsies, and 86% had a positive family history. Thirty-one percent of Black women in our study were high risk, while nationally, 8.2 to 13.3% of Black women aged 50 to 59 years are considered high risk.^50,51 Of the Black high-risk group with a high Gail/BCRAT score, 94% had a positive family history, and 33% had a history of breast biopsy (Table 2).

Of the 35 high-risk patients 26 (74%) patients accepted consultations for chemoprevention and 5 (19%) started chemoprevention. Of this high-risk group, 13 (37%) patients were referred for genetic counseling (Table 3).⁴⁴ The prevalence of PTSD was present in 31% of high-risk women and 29% of the cohort (Figure).The lifestyle questions indicated that, among all participants, 79% had an overweight or obese body mass index; 58% exercised weekly; 51% consumed alcohol; 14% were smokers; and 21% consumed 3 to 4 servings of fruits/vegetables daily.

Discussion

Breast cancer is the most common cancer in women.⁵² The number of women with breast cancer in the VHA has more than tripled from 1995 to 2012.¹ The lifetime risk of developing breast cancer in the general population is about 13%.⁵⁰ This rate can be affected by risk factors including age, hormone exposure, family history, radiation exposure, and lifestyle factors, such as weight and alcohol use.^6,52-56 In the United States, invasive breast cancer affects 1 in 8 women.^50,52,57

Our screened population showed nearly 3 times as many women veterans were at an increased risk for breast cancer when compared with historical averages in US women. This difference may be based on a high rate of prior breast biopsies or positive family history, although a provocative study using the Surveillance, Epidemiology, and End Results database showed military women to have higher rates of breast cancer as well.⁹ Historically, Blacks are vastly understudied in clinical research with only 5% representation on a national level.^5,58 The urban locations of both pilot sites (Washington, DC and Bronx, NY) allowed for the inclusion of minority patients in our study. We found that the rates of breast cancer in Black women veterans to be higher than seen nationally, possibly prompting further screening initiatives for this understudied population.

Our pilot study’s chemoprevention utilization (19%) was double the < 10% seen in the national population.^33-35 The presence of a knowledgeable breast health practitioner to recruit study participants and offer personalized counseling to women veterans is a likely factor in overcoming barriers to chemopreventive acceptance. These participants may have been motivated to seek care for their high-risk status given a strong family history and prior breast biopsies.

Interestingly, a 3-fold higher PTSD rate was seen in this pilot population (29%) when compared with PTSD rates in the general female population (7-10%) and still one-third higher than the general population of women veterans (20%).^45-47 Mental health, anxiety, and PTSD have been barriers to patients who sought treatment and have been implicated in poor adherence to medical advice.^48,49 Cancer screening can induce anxiety in patients, and it may be amplified in patients with PTSD. It was remarkable that although adherence with screening recommendations is decreased when PTSD is present, our patient population demonstrated a higher rate of screening adherence.

Women who are seen at the VA often use multiple clinical specialties, and their EMR can be accessed across VA medical centers nationwide. Therefore, identifying women veterans who meet screening criteria is easily attainable within the VA.

When comparing high-risk with average risk women, the lifestyle results (BMI, smoking history, exercise and consumption of fruits, vegetables and alcohol) were essentially the same. Lifestyle factors were similar to national population rates and were unlikely to impact risk levels.

Limitations

Study limitations included a high number of self-referrals and the large percentage of patients with a family history of breast cancer, making them more likely to seek screening. The higher-than-average risk of breast cancer may be driven by a high rate of breast biopsies and a strong family history. Lifestyle metrics could not be accurately compared to other national assessments of lifestyle factors due to the difference in data points that we used or the format of our questions.

Conclusions

As the number of women veterans increases and the incidence of breast cancer in women veterans rise, chemoprevention options should follow national guidelines. To our knowledge, this is the only oncology study with 60% Black women veterans. This study had a higher participation rate for Black women veterans than is typically seen in national research studies and shows the VA to be a germane source for further understanding of an understudied population that may benefit from increased screening for breast cancer.

A team-based, multidisciplinary model that meets the unique healthcare needs of women veterans results in a patient-centric delivery of care for assessing breast cancer risk status and prevention options. This model can be replicated nationally by directing primary care physicians and women’s health practitioners to a risk-assessment questionnaire and referring high-risk women for appropriate preventative care. Given that these results show chemoprevention adherence rates doubled those seen nationally, perhaps techniques used within this VA pilot study may be adapted to decrease breast cancer incidence nationally.

Since the rate of PTSD among women veterans is triple the national average, we would expect adherence rates to be lower in our patient cohort. However, the multidisciplinary approach we used in this study (eg, 1:1 consultation with oncologist; genetic counseling referrals; mental health support available), may have improved adherence rates. Perhaps the high rates of PTSD seen in the VA patient population can be a useful way to explore patient adherence rates in those with mental illness and medical conditions.

Future research with a larger cohort may lead to greater insight into the correlation between PTSD and adherence to treatment. Exploring the connection between breast cancer, epigenetics, and specific military service-related exposures could be an area of analysis among this veteran population exhibiting increased breast cancer rates. VAMCs are situated in rural, suburban, and urban locations across the United States and offers a diverse socioeconomic and ethnic patient population for inclusion in clinical investigations. Women veterans make up a small subpopulation of women in the United States, but it is worth considering VA patients as an untapped resource for research collaboration.

Acknowledgements

The authors thank Steven Sanchez and Marissa Vallette, PhD, Breast Health Research Group. This research project was approved by the James J. Peters VA Medical Center Quality Executive Committee and the Washington, DC VA Medical Center Institutional Review Board. This work was supported by the US Department of Veterans Affairs. This work did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Author disclosures

The authors report no actual or potential conflicts of interest with regard to this article.

Disclaimer

The opinions expressed herein are those of the authors and do not necessarily reflect those of Federal Practitioner, Frontline Medical Communications Inc., the US Government, or any of its agencies.

Sexual dysfunction is a common problem among breast cancer survivors, but it’s also an issue inadequately addressed by either ob.gyns. or hematologists and oncologists, according to Erin Keyser, MD, the program director of the San Antonio Uniformed Services Health Education Consortium. Dr. Keyser discussed management of sexual dysfunction and a variety of other issues frequently faced by women who have survived breast cancer at the at the 2021 virtual meeting of the American College of Obstetricians and Gynecologists.

“Despite the fact that no specialty is better qualified to render care for this consequence of cancer treatments, many obstetrician-gynecologists feel uncomfortable or ill-equipped to address sexual pain in women affected by cancer,” Dr. Keyser quoted from a 2016 article in Obstetrics & Gynecology about the sexual health of women affected by cancer. As a breast cancer survivor herself, Dr. Keyser said hematologists and oncologists are even less equipped to discuss sexual health, “so oftentimes patients get punted between their hem-onc and their gyn,” with each telling the patient to ask the other specialist.

“There’s plenty of data in chronic health disease that maintaining sexual function for women is an indicator of the overall quality of life and that many women really don’t want to bring this up,” Dr. Keyser told attendees, so the onus is on the ob.gyn. to bring it up.

The effects of breast cancer treatment can impact women’s body image, fertility, menopause, sexual function, osteoporosis, and cardiovascular disease, but the bulk of Dr. Keyser’s talk focused on sexual health and bilateral salpingo-oophorectomy (BSO).

Lauren Streicher, MD, a clinical professor of obstetrics and gynecology at Northwestern University, Chicago, thought Dr. Keyser’s talk was useful for the general gynecologist but had some concerns about a few parts.

“She gave a very thoughtful analysis of whether someone should have their ovaries removed or not in a breast cancer diagnosis, ” Dr. Streicher said in an interview. “I would have liked to hear more about the consequences of an early menopause in women in terms of heart health, bone health, and cognitive function.”

Dr. Keyser noted that her talk pertained mostly to survivors of estrogen receptor (ER)–positive breast cancer since that population tends to struggle most with side effects of treatment. The most common medications used in this population are tamoxifen and aromatase inhibitors – such as anastrazole, letrozole, and exemestane – and these medications can affect management of different concerns.
 

Current guidance on ovarian removal

For women with a BRCA mutation, ACOG clinical guidance already exists regarding BSO. For other women, the complementary TEXT and SOFT trials changed the management of breast cancer treatment in premenopausal women, Dr. Keyser said.

Before these trials, postmenopausal hormone receptor–positive women began aromatase inhibitors and premenopausal HR-positive women began tamoxifen. These trials found that premenopausal women with HR-positive early breast cancer were less likely to experience recurrence when receiving adjuvant treatment with exemestane plus ovarian suppression compared to tamoxifen plus ovarian suppression. Ovarian suppression was achieved by either GnRH agonist injections, surgical removal of the ovaries, or radiation therapy to the ovaries.

The side effects of these treatments included hot flushes (92%), depression (87%), musculoskeletal symptoms (89%), vaginal dryness (52%), decreased libido (45%), dyspareunia (31%), osteoporosis (39%), insomnia (58%), and fatigue (61%). These are all quality of life concerns, Dr. Keyser said, and these findings raise questions about the consequences of long-term ovarian suppression. Findings from the Nurses’ Health Study showed that BSO before age 47.5 years resulted in lower mortality from ovarian cancer and breast cancer but was linked in women under 50 to increased all-cause mortality and mortality from coronary heart disease, lung cancer, and colorectal cancer, compared with ovarian conservation. Further, 74% of women who undergo risk-reducing BSO experience sexual dysfunction.

The bottom line, Dr. Keyser said, is that “premature removal of ovaries is not completely benign.” Her own recommendation is to follow ACOG guidance for women with BRCA mutations and, for women aged under 35 years, use ovarian suppression for 5-10 years, after which ovarian function may resume along with improved quality of life. In women aged over 40, remove ovaries since, after 5-10 years of treatment, there’s likely no benefit of retaining ovaries.
 

Addressing sexual health

Dyspareunia affects up to 45% of cancer survivors, Dr. Keyser said, and multiple treatment options exist for breast cancer survivors. The therapies she discussed included lubricants, moisturizers, local vaginal estrogen, DHEA, ospemifene, and CO₂ laser therapy.

Though Dr. Keyser briefly touched on vaginal lubricants and moisturizers, Dr. Streicher was disappointed that Dr. Keyser did not clearly define and differentiate between lubricants and moisturizers or mention hyaluronic acid products. Dr. Streicher also disagreed with the way Dr. Keyser represented the benefits of coconut oil as a lubricant. “Oils are not condom compatible and are known to potentially increase the risk of infection, and not just from poor handwashing,” Dr. Streicher said.

Small retrospective studies support the safety of topical vaginal estrogen in breast cancer survivors, Dr. Keyser said, and the 10-mcg Vagifem tablet and vaginal estradiol ring appear to have the lowest systemic absorption. ACOG guidance recommends that women taking aromatase inhibitors who don’t respond to nonhormonal approaches may benefit from switching temporarily to tamoxifen with vaginal estrogen and then returning to aromatase inhibitors. However, Dr. Keyser said there’s plenty of data to support using vaginal estrogen in patients taking aromatase inhibitors.

“I do feel that it’s safe for patients, whether they’re on tamoxifen or aromatase inhibitors, to take vaginal estrogen,” Dr. Keyser said. “I usually stick with the estradiol vaginal ring or the estradiol tablet, and I base that on a patient’s comfort with placing and removing a ring.” She also, instead of asking the patient’s hematologist-oncologist, simply notifies them of the treatment since most hematologist-oncologists are less familiar with the data.

Another effective option is vaginal DHEA/prasterone, which can significantly improve sexual desire, arousal, pain, and overall sexual function. Although breast cancer patients were included in early studies on DHEA, Intrarosa manufacturers excluded breast cancer patients in their Food and Drug Administration application, resulting in a package stating that “use of exogenous estrogen is contraindicated in women with a known or suspected history of breast cancer” and that “Intrarosa has not been studied in women with a history of breast cancer.” While that’s true for Intrarosa specifically, DHEA has been studied in breast cancer patients, Dr. Keyser said, so she expects to see more research in this area.

Ospemifene is another option for improving vulvovaginal atrophy but cannot be taken at the same time as tamoxifen. It has similar chemopreventive effects as tamoxifen in rat studies, but it’s not as effective. It’s a reasonable option in women with refractory genitourinary syndrome of menopause (GSM) who have completed their 5-10 years of adjuvant therapy and have no history of venous thromboembolism.

Dr. Keyser said CO₂ laser therapy is still being studied for treating GSM, and current data have shown benefits for dyspareunia and vaginal dryness without documented harms. There have now been randomized, controlled trials; however, since it’s not FDA approved, it’s not covered by insurance and costs approximately $5,000 for three treatments.

Dr. Streicher was glad to see Dr. Keyser’s discussion of the safety and types of local vaginal estrogen, “although she neglected to mention the 4-mcg vaginal suppository, Imvexxy, which has the lowest systemic absorption,” Dr. Streicher said. Dr. Streicher also felt the inclusion of DHEA/prasterone and ospemifene were also important, especially since the latter is “underutilized in breast cancer patients.”

The information provided on CO₂ laser therapy, however, was problematic, Dr. Streicher said, given that long-term and randomized, controlled studies have now been published. Dr. Streicher also noted that two of the devices listed on the presentation slide, Thermiva and Voltiva, are radiofrequency, not laser devices.

Aside from these treatment options, the most consistent predictor of satisfying sexual experiences in women with breast cancer is the quality of their relationships, Dr. Keyser said, so couples counseling is recommended, and treatments in general are more effective with regularly sexual activity.

In discussing nonhormonal options for treating vasomotor symptoms, Dr. Keyser recommended venlafaxine, gabapentin, and low-dose paroxetine (though SSRIs and tamoxifen are contraindicated since they may reduce tamoxifen’s efficacy).

These are all off label, Dr. Streicher said it was important to note, and she would have liked to have seen a mention of the development of KNdy neurokinin disrupters along with a more in-depth discussion about which lifestyle modifications and botanicals have been shown in randomized, controlled trials to mitigate vasomotor symptoms.

Dr. Keyser wrapped up with a few additional notes and takeaways:

• The only safe reversible long-term option for contraception in HR-positive breast cancer survivors is the Paraguard IUD.
• It’s important to discuss fertility with breast cancer patients and survivors since a majority report unmet needs in this area.
• Patients taking tamoxifen need to be sure to report any vaginal spotting or bleeding since it increases risk of endometrial cancer in postmenopausal women.
• Screen for depression and anxiety.
• Ask women about sexual health and hot flashes.
• Ensure that they’re getting bone screening.
• A recommended resource is Living Beyond Breast Cancer.

Dr. Keyser had no disclosures. Dr. Streicher has consulted for Astellas Pharma and Church & Dwight, and she owns investments in InControl Medical and Sermonix Pharmaceuticals.

Sexual dysfunction is a common problem among breast cancer survivors, but it’s also an issue inadequately addressed by either ob.gyns. or hematologists and oncologists, according to Erin Keyser, MD, the program director of the San Antonio Uniformed Services Health Education Consortium. Dr. Keyser discussed management of sexual dysfunction and a variety of other issues frequently faced by women who have survived breast cancer at the at the 2021 virtual meeting of the American College of Obstetricians and Gynecologists.

“Despite the fact that no specialty is better qualified to render care for this consequence of cancer treatments, many obstetrician-gynecologists feel uncomfortable or ill-equipped to address sexual pain in women affected by cancer,” Dr. Keyser quoted from a 2016 article in Obstetrics & Gynecology about the sexual health of women affected by cancer. As a breast cancer survivor herself, Dr. Keyser said hematologists and oncologists are even less equipped to discuss sexual health, “so oftentimes patients get punted between their hem-onc and their gyn,” with each telling the patient to ask the other specialist.

“There’s plenty of data in chronic health disease that maintaining sexual function for women is an indicator of the overall quality of life and that many women really don’t want to bring this up,” Dr. Keyser told attendees, so the onus is on the ob.gyn. to bring it up.

The effects of breast cancer treatment can impact women’s body image, fertility, menopause, sexual function, osteoporosis, and cardiovascular disease, but the bulk of Dr. Keyser’s talk focused on sexual health and bilateral salpingo-oophorectomy (BSO).

Lauren Streicher, MD, a clinical professor of obstetrics and gynecology at Northwestern University, Chicago, thought Dr. Keyser’s talk was useful for the general gynecologist but had some concerns about a few parts.

“She gave a very thoughtful analysis of whether someone should have their ovaries removed or not in a breast cancer diagnosis, ” Dr. Streicher said in an interview. “I would have liked to hear more about the consequences of an early menopause in women in terms of heart health, bone health, and cognitive function.”

Dr. Keyser noted that her talk pertained mostly to survivors of estrogen receptor (ER)–positive breast cancer since that population tends to struggle most with side effects of treatment. The most common medications used in this population are tamoxifen and aromatase inhibitors – such as anastrazole, letrozole, and exemestane – and these medications can affect management of different concerns.
 

Current guidance on ovarian removal

For women with a BRCA mutation, ACOG clinical guidance already exists regarding BSO. For other women, the complementary TEXT and SOFT trials changed the management of breast cancer treatment in premenopausal women, Dr. Keyser said.

Before these trials, postmenopausal hormone receptor–positive women began aromatase inhibitors and premenopausal HR-positive women began tamoxifen. These trials found that premenopausal women with HR-positive early breast cancer were less likely to experience recurrence when receiving adjuvant treatment with exemestane plus ovarian suppression compared to tamoxifen plus ovarian suppression. Ovarian suppression was achieved by either GnRH agonist injections, surgical removal of the ovaries, or radiation therapy to the ovaries.

The side effects of these treatments included hot flushes (92%), depression (87%), musculoskeletal symptoms (89%), vaginal dryness (52%), decreased libido (45%), dyspareunia (31%), osteoporosis (39%), insomnia (58%), and fatigue (61%). These are all quality of life concerns, Dr. Keyser said, and these findings raise questions about the consequences of long-term ovarian suppression. Findings from the Nurses’ Health Study showed that BSO before age 47.5 years resulted in lower mortality from ovarian cancer and breast cancer but was linked in women under 50 to increased all-cause mortality and mortality from coronary heart disease, lung cancer, and colorectal cancer, compared with ovarian conservation. Further, 74% of women who undergo risk-reducing BSO experience sexual dysfunction.

The bottom line, Dr. Keyser said, is that “premature removal of ovaries is not completely benign.” Her own recommendation is to follow ACOG guidance for women with BRCA mutations and, for women aged under 35 years, use ovarian suppression for 5-10 years, after which ovarian function may resume along with improved quality of life. In women aged over 40, remove ovaries since, after 5-10 years of treatment, there’s likely no benefit of retaining ovaries.
 

Addressing sexual health

Dyspareunia affects up to 45% of cancer survivors, Dr. Keyser said, and multiple treatment options exist for breast cancer survivors. The therapies she discussed included lubricants, moisturizers, local vaginal estrogen, DHEA, ospemifene, and CO₂ laser therapy.

Though Dr. Keyser briefly touched on vaginal lubricants and moisturizers, Dr. Streicher was disappointed that Dr. Keyser did not clearly define and differentiate between lubricants and moisturizers or mention hyaluronic acid products. Dr. Streicher also disagreed with the way Dr. Keyser represented the benefits of coconut oil as a lubricant. “Oils are not condom compatible and are known to potentially increase the risk of infection, and not just from poor handwashing,” Dr. Streicher said.

Small retrospective studies support the safety of topical vaginal estrogen in breast cancer survivors, Dr. Keyser said, and the 10-mcg Vagifem tablet and vaginal estradiol ring appear to have the lowest systemic absorption. ACOG guidance recommends that women taking aromatase inhibitors who don’t respond to nonhormonal approaches may benefit from switching temporarily to tamoxifen with vaginal estrogen and then returning to aromatase inhibitors. However, Dr. Keyser said there’s plenty of data to support using vaginal estrogen in patients taking aromatase inhibitors.

“I do feel that it’s safe for patients, whether they’re on tamoxifen or aromatase inhibitors, to take vaginal estrogen,” Dr. Keyser said. “I usually stick with the estradiol vaginal ring or the estradiol tablet, and I base that on a patient’s comfort with placing and removing a ring.” She also, instead of asking the patient’s hematologist-oncologist, simply notifies them of the treatment since most hematologist-oncologists are less familiar with the data.

Another effective option is vaginal DHEA/prasterone, which can significantly improve sexual desire, arousal, pain, and overall sexual function. Although breast cancer patients were included in early studies on DHEA, Intrarosa manufacturers excluded breast cancer patients in their Food and Drug Administration application, resulting in a package stating that “use of exogenous estrogen is contraindicated in women with a known or suspected history of breast cancer” and that “Intrarosa has not been studied in women with a history of breast cancer.” While that’s true for Intrarosa specifically, DHEA has been studied in breast cancer patients, Dr. Keyser said, so she expects to see more research in this area.

Ospemifene is another option for improving vulvovaginal atrophy but cannot be taken at the same time as tamoxifen. It has similar chemopreventive effects as tamoxifen in rat studies, but it’s not as effective. It’s a reasonable option in women with refractory genitourinary syndrome of menopause (GSM) who have completed their 5-10 years of adjuvant therapy and have no history of venous thromboembolism.

Dr. Keyser said CO₂ laser therapy is still being studied for treating GSM, and current data have shown benefits for dyspareunia and vaginal dryness without documented harms. There have now been randomized, controlled trials; however, since it’s not FDA approved, it’s not covered by insurance and costs approximately $5,000 for three treatments.

Dr. Streicher was glad to see Dr. Keyser’s discussion of the safety and types of local vaginal estrogen, “although she neglected to mention the 4-mcg vaginal suppository, Imvexxy, which has the lowest systemic absorption,” Dr. Streicher said. Dr. Streicher also felt the inclusion of DHEA/prasterone and ospemifene were also important, especially since the latter is “underutilized in breast cancer patients.”

The information provided on CO₂ laser therapy, however, was problematic, Dr. Streicher said, given that long-term and randomized, controlled studies have now been published. Dr. Streicher also noted that two of the devices listed on the presentation slide, Thermiva and Voltiva, are radiofrequency, not laser devices.

Aside from these treatment options, the most consistent predictor of satisfying sexual experiences in women with breast cancer is the quality of their relationships, Dr. Keyser said, so couples counseling is recommended, and treatments in general are more effective with regularly sexual activity.

In discussing nonhormonal options for treating vasomotor symptoms, Dr. Keyser recommended venlafaxine, gabapentin, and low-dose paroxetine (though SSRIs and tamoxifen are contraindicated since they may reduce tamoxifen’s efficacy).

These are all off label, Dr. Streicher said it was important to note, and she would have liked to have seen a mention of the development of KNdy neurokinin disrupters along with a more in-depth discussion about which lifestyle modifications and botanicals have been shown in randomized, controlled trials to mitigate vasomotor symptoms.

Dr. Keyser wrapped up with a few additional notes and takeaways:

• The only safe reversible long-term option for contraception in HR-positive breast cancer survivors is the Paraguard IUD.
• It’s important to discuss fertility with breast cancer patients and survivors since a majority report unmet needs in this area.
• Patients taking tamoxifen need to be sure to report any vaginal spotting or bleeding since it increases risk of endometrial cancer in postmenopausal women.
• Screen for depression and anxiety.
• Ask women about sexual health and hot flashes.
• Ensure that they’re getting bone screening.
• A recommended resource is Living Beyond Breast Cancer.

Dr. Keyser had no disclosures. Dr. Streicher has consulted for Astellas Pharma and Church & Dwight, and she owns investments in InControl Medical and Sermonix Pharmaceuticals.

Sexual dysfunction is a common problem among breast cancer survivors, but it’s also an issue inadequately addressed by either ob.gyns. or hematologists and oncologists, according to Erin Keyser, MD, the program director of the San Antonio Uniformed Services Health Education Consortium. Dr. Keyser discussed management of sexual dysfunction and a variety of other issues frequently faced by women who have survived breast cancer at the at the 2021 virtual meeting of the American College of Obstetricians and Gynecologists.

“Despite the fact that no specialty is better qualified to render care for this consequence of cancer treatments, many obstetrician-gynecologists feel uncomfortable or ill-equipped to address sexual pain in women affected by cancer,” Dr. Keyser quoted from a 2016 article in Obstetrics & Gynecology about the sexual health of women affected by cancer. As a breast cancer survivor herself, Dr. Keyser said hematologists and oncologists are even less equipped to discuss sexual health, “so oftentimes patients get punted between their hem-onc and their gyn,” with each telling the patient to ask the other specialist.

“There’s plenty of data in chronic health disease that maintaining sexual function for women is an indicator of the overall quality of life and that many women really don’t want to bring this up,” Dr. Keyser told attendees, so the onus is on the ob.gyn. to bring it up.

The effects of breast cancer treatment can impact women’s body image, fertility, menopause, sexual function, osteoporosis, and cardiovascular disease, but the bulk of Dr. Keyser’s talk focused on sexual health and bilateral salpingo-oophorectomy (BSO).

Lauren Streicher, MD, a clinical professor of obstetrics and gynecology at Northwestern University, Chicago, thought Dr. Keyser’s talk was useful for the general gynecologist but had some concerns about a few parts.

“She gave a very thoughtful analysis of whether someone should have their ovaries removed or not in a breast cancer diagnosis, ” Dr. Streicher said in an interview. “I would have liked to hear more about the consequences of an early menopause in women in terms of heart health, bone health, and cognitive function.”

Dr. Keyser noted that her talk pertained mostly to survivors of estrogen receptor (ER)–positive breast cancer since that population tends to struggle most with side effects of treatment. The most common medications used in this population are tamoxifen and aromatase inhibitors – such as anastrazole, letrozole, and exemestane – and these medications can affect management of different concerns.
 

Current guidance on ovarian removal

For women with a BRCA mutation, ACOG clinical guidance already exists regarding BSO. For other women, the complementary TEXT and SOFT trials changed the management of breast cancer treatment in premenopausal women, Dr. Keyser said.

Before these trials, postmenopausal hormone receptor–positive women began aromatase inhibitors and premenopausal HR-positive women began tamoxifen. These trials found that premenopausal women with HR-positive early breast cancer were less likely to experience recurrence when receiving adjuvant treatment with exemestane plus ovarian suppression compared to tamoxifen plus ovarian suppression. Ovarian suppression was achieved by either GnRH agonist injections, surgical removal of the ovaries, or radiation therapy to the ovaries.

The side effects of these treatments included hot flushes (92%), depression (87%), musculoskeletal symptoms (89%), vaginal dryness (52%), decreased libido (45%), dyspareunia (31%), osteoporosis (39%), insomnia (58%), and fatigue (61%). These are all quality of life concerns, Dr. Keyser said, and these findings raise questions about the consequences of long-term ovarian suppression. Findings from the Nurses’ Health Study showed that BSO before age 47.5 years resulted in lower mortality from ovarian cancer and breast cancer but was linked in women under 50 to increased all-cause mortality and mortality from coronary heart disease, lung cancer, and colorectal cancer, compared with ovarian conservation. Further, 74% of women who undergo risk-reducing BSO experience sexual dysfunction.

The bottom line, Dr. Keyser said, is that “premature removal of ovaries is not completely benign.” Her own recommendation is to follow ACOG guidance for women with BRCA mutations and, for women aged under 35 years, use ovarian suppression for 5-10 years, after which ovarian function may resume along with improved quality of life. In women aged over 40, remove ovaries since, after 5-10 years of treatment, there’s likely no benefit of retaining ovaries.
 

Addressing sexual health

Dyspareunia affects up to 45% of cancer survivors, Dr. Keyser said, and multiple treatment options exist for breast cancer survivors. The therapies she discussed included lubricants, moisturizers, local vaginal estrogen, DHEA, ospemifene, and CO₂ laser therapy.

Though Dr. Keyser briefly touched on vaginal lubricants and moisturizers, Dr. Streicher was disappointed that Dr. Keyser did not clearly define and differentiate between lubricants and moisturizers or mention hyaluronic acid products. Dr. Streicher also disagreed with the way Dr. Keyser represented the benefits of coconut oil as a lubricant. “Oils are not condom compatible and are known to potentially increase the risk of infection, and not just from poor handwashing,” Dr. Streicher said.

Small retrospective studies support the safety of topical vaginal estrogen in breast cancer survivors, Dr. Keyser said, and the 10-mcg Vagifem tablet and vaginal estradiol ring appear to have the lowest systemic absorption. ACOG guidance recommends that women taking aromatase inhibitors who don’t respond to nonhormonal approaches may benefit from switching temporarily to tamoxifen with vaginal estrogen and then returning to aromatase inhibitors. However, Dr. Keyser said there’s plenty of data to support using vaginal estrogen in patients taking aromatase inhibitors.

“I do feel that it’s safe for patients, whether they’re on tamoxifen or aromatase inhibitors, to take vaginal estrogen,” Dr. Keyser said. “I usually stick with the estradiol vaginal ring or the estradiol tablet, and I base that on a patient’s comfort with placing and removing a ring.” She also, instead of asking the patient’s hematologist-oncologist, simply notifies them of the treatment since most hematologist-oncologists are less familiar with the data.

Another effective option is vaginal DHEA/prasterone, which can significantly improve sexual desire, arousal, pain, and overall sexual function. Although breast cancer patients were included in early studies on DHEA, Intrarosa manufacturers excluded breast cancer patients in their Food and Drug Administration application, resulting in a package stating that “use of exogenous estrogen is contraindicated in women with a known or suspected history of breast cancer” and that “Intrarosa has not been studied in women with a history of breast cancer.” While that’s true for Intrarosa specifically, DHEA has been studied in breast cancer patients, Dr. Keyser said, so she expects to see more research in this area.

Ospemifene is another option for improving vulvovaginal atrophy but cannot be taken at the same time as tamoxifen. It has similar chemopreventive effects as tamoxifen in rat studies, but it’s not as effective. It’s a reasonable option in women with refractory genitourinary syndrome of menopause (GSM) who have completed their 5-10 years of adjuvant therapy and have no history of venous thromboembolism.

Dr. Keyser said CO₂ laser therapy is still being studied for treating GSM, and current data have shown benefits for dyspareunia and vaginal dryness without documented harms. There have now been randomized, controlled trials; however, since it’s not FDA approved, it’s not covered by insurance and costs approximately $5,000 for three treatments.

Dr. Streicher was glad to see Dr. Keyser’s discussion of the safety and types of local vaginal estrogen, “although she neglected to mention the 4-mcg vaginal suppository, Imvexxy, which has the lowest systemic absorption,” Dr. Streicher said. Dr. Streicher also felt the inclusion of DHEA/prasterone and ospemifene were also important, especially since the latter is “underutilized in breast cancer patients.”

The information provided on CO₂ laser therapy, however, was problematic, Dr. Streicher said, given that long-term and randomized, controlled studies have now been published. Dr. Streicher also noted that two of the devices listed on the presentation slide, Thermiva and Voltiva, are radiofrequency, not laser devices.

Aside from these treatment options, the most consistent predictor of satisfying sexual experiences in women with breast cancer is the quality of their relationships, Dr. Keyser said, so couples counseling is recommended, and treatments in general are more effective with regularly sexual activity.

In discussing nonhormonal options for treating vasomotor symptoms, Dr. Keyser recommended venlafaxine, gabapentin, and low-dose paroxetine (though SSRIs and tamoxifen are contraindicated since they may reduce tamoxifen’s efficacy).

These are all off label, Dr. Streicher said it was important to note, and she would have liked to have seen a mention of the development of KNdy neurokinin disrupters along with a more in-depth discussion about which lifestyle modifications and botanicals have been shown in randomized, controlled trials to mitigate vasomotor symptoms.

Dr. Keyser wrapped up with a few additional notes and takeaways:

• The only safe reversible long-term option for contraception in HR-positive breast cancer survivors is the Paraguard IUD.
• It’s important to discuss fertility with breast cancer patients and survivors since a majority report unmet needs in this area.
• Patients taking tamoxifen need to be sure to report any vaginal spotting or bleeding since it increases risk of endometrial cancer in postmenopausal women.
• Screen for depression and anxiety.
• Ask women about sexual health and hot flashes.
• Ensure that they’re getting bone screening.
• A recommended resource is Living Beyond Breast Cancer.

Dr. Keyser had no disclosures. Dr. Streicher has consulted for Astellas Pharma and Church & Dwight, and she owns investments in InControl Medical and Sermonix Pharmaceuticals.