Article

Key clinical point: Patritumab deruxtecan (HER3-DXd) showed meaningful clinical efficacy and a manageable safety profile across breast cancer (BC) subtypes in heavily pretreated patients with human epidermal growth factor receptor 3 (HER3)-expressing metastatic BC.

Major finding: The objective response rate was 30.1% (95% CI 21.8%-39.4%) in hormone receptor-positive/HER2-negative BC, 22.6% (95% CI 12.3%-36.2%) in triple-negative BC, and 42.9% (95% CI 17.1%-71.1%) in HER2-positive BC. Although 71.4% of patients reported grade ≥3 treatment-emergent adverse events (TEAE), the overall rate of treatment discontinuation due to TEAE was low (9.9%).

Study details: Findings are from a phase I/II trial including 182 heavily pretreated patients with HER3-expressing advanced BC who received HER3-DXd.

Disclosures: This trial was sponsored by Daiichi Sankyo Co., Ltd. Nine authors declared being employees of or holding stocks and other ownership interests in Daiichi Sankyo. The other authors declared ties with various sources, including Daiichi Sankyo.

Source: Krop IE et al. Patritumab deruxtecan (HER3-DXd), a human epidermal growth factor receptor 3-directed antibody-drug conjugate, in patients with previously treated human epidermal growth factor receptor 3-expressing metastatic breast cancer: A multicenter, phase I/II trial. J Clin Oncol. 2023 (Oct 6). doi: 10.1200/JCO.23.00882

Key clinical point: Patritumab deruxtecan (HER3-DXd) showed meaningful clinical efficacy and a manageable safety profile across breast cancer (BC) subtypes in heavily pretreated patients with human epidermal growth factor receptor 3 (HER3)-expressing metastatic BC.

Major finding: The objective response rate was 30.1% (95% CI 21.8%-39.4%) in hormone receptor-positive/HER2-negative BC, 22.6% (95% CI 12.3%-36.2%) in triple-negative BC, and 42.9% (95% CI 17.1%-71.1%) in HER2-positive BC. Although 71.4% of patients reported grade ≥3 treatment-emergent adverse events (TEAE), the overall rate of treatment discontinuation due to TEAE was low (9.9%).

Study details: Findings are from a phase I/II trial including 182 heavily pretreated patients with HER3-expressing advanced BC who received HER3-DXd.

Disclosures: This trial was sponsored by Daiichi Sankyo Co., Ltd. Nine authors declared being employees of or holding stocks and other ownership interests in Daiichi Sankyo. The other authors declared ties with various sources, including Daiichi Sankyo.

Source: Krop IE et al. Patritumab deruxtecan (HER3-DXd), a human epidermal growth factor receptor 3-directed antibody-drug conjugate, in patients with previously treated human epidermal growth factor receptor 3-expressing metastatic breast cancer: A multicenter, phase I/II trial. J Clin Oncol. 2023 (Oct 6). doi: 10.1200/JCO.23.00882

Key clinical point: Patritumab deruxtecan (HER3-DXd) showed meaningful clinical efficacy and a manageable safety profile across breast cancer (BC) subtypes in heavily pretreated patients with human epidermal growth factor receptor 3 (HER3)-expressing metastatic BC.

Major finding: The objective response rate was 30.1% (95% CI 21.8%-39.4%) in hormone receptor-positive/HER2-negative BC, 22.6% (95% CI 12.3%-36.2%) in triple-negative BC, and 42.9% (95% CI 17.1%-71.1%) in HER2-positive BC. Although 71.4% of patients reported grade ≥3 treatment-emergent adverse events (TEAE), the overall rate of treatment discontinuation due to TEAE was low (9.9%).

Study details: Findings are from a phase I/II trial including 182 heavily pretreated patients with HER3-expressing advanced BC who received HER3-DXd.

Disclosures: This trial was sponsored by Daiichi Sankyo Co., Ltd. Nine authors declared being employees of or holding stocks and other ownership interests in Daiichi Sankyo. The other authors declared ties with various sources, including Daiichi Sankyo.

Source: Krop IE et al. Patritumab deruxtecan (HER3-DXd), a human epidermal growth factor receptor 3-directed antibody-drug conjugate, in patients with previously treated human epidermal growth factor receptor 3-expressing metastatic breast cancer: A multicenter, phase I/II trial. J Clin Oncol. 2023 (Oct 6). doi: 10.1200/JCO.23.00882

Key clinical point: Neoadjuvant chemotherapy (NAC) may increase the odds of a pathological complete response (pCR) in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2−) breast cancer (BC) and BRCA1 mutation vs in those with sporadic BC.

Major finding: The rate of achieving a pCR was significantly higher in BRCA1/2 and BRCA1 mutation carriers vs non-carriers (16% and 38%, respectively, vs 7.8%; P < .001), with BRCA1 mutation carrier vs non-carrier status being associated with higher odds of achieving a pCR (odds ratio 6.31; P = .002).

Study details: Findings are from a retrospective study including 522 patients with HR+/HER2− BC who received NAC, of whom 21 and 38 patients had BRCA1 and BRCA2 mutations, respectively.

Disclosures: This study was partly supported by a  US National Institutes of Health/National Cancer Institute Cancer Center Support grant. The authors declared no conflicts of interest.

Source: Myers SP et al. Mutational status is associated with a higher rate of pathologic complete response after neoadjuvant chemotherapy in hormone receptor-positive breast cancer. Ann Surg Oncol. 2023 (Oct 5). doi: 10.1245/s10434-023-14319-0

Key clinical point: Neoadjuvant chemotherapy (NAC) may increase the odds of a pathological complete response (pCR) in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2−) breast cancer (BC) and BRCA1 mutation vs in those with sporadic BC.

Major finding: The rate of achieving a pCR was significantly higher in BRCA1/2 and BRCA1 mutation carriers vs non-carriers (16% and 38%, respectively, vs 7.8%; P < .001), with BRCA1 mutation carrier vs non-carrier status being associated with higher odds of achieving a pCR (odds ratio 6.31; P = .002).

Study details: Findings are from a retrospective study including 522 patients with HR+/HER2− BC who received NAC, of whom 21 and 38 patients had BRCA1 and BRCA2 mutations, respectively.

Disclosures: This study was partly supported by a  US National Institutes of Health/National Cancer Institute Cancer Center Support grant. The authors declared no conflicts of interest.

Source: Myers SP et al. Mutational status is associated with a higher rate of pathologic complete response after neoadjuvant chemotherapy in hormone receptor-positive breast cancer. Ann Surg Oncol. 2023 (Oct 5). doi: 10.1245/s10434-023-14319-0

Key clinical point: Neoadjuvant chemotherapy (NAC) may increase the odds of a pathological complete response (pCR) in patients with hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2−) breast cancer (BC) and BRCA1 mutation vs in those with sporadic BC.

Major finding: The rate of achieving a pCR was significantly higher in BRCA1/2 and BRCA1 mutation carriers vs non-carriers (16% and 38%, respectively, vs 7.8%; P < .001), with BRCA1 mutation carrier vs non-carrier status being associated with higher odds of achieving a pCR (odds ratio 6.31; P = .002).

Study details: Findings are from a retrospective study including 522 patients with HR+/HER2− BC who received NAC, of whom 21 and 38 patients had BRCA1 and BRCA2 mutations, respectively.

Disclosures: This study was partly supported by a  US National Institutes of Health/National Cancer Institute Cancer Center Support grant. The authors declared no conflicts of interest.

Source: Myers SP et al. Mutational status is associated with a higher rate of pathologic complete response after neoadjuvant chemotherapy in hormone receptor-positive breast cancer. Ann Surg Oncol. 2023 (Oct 5). doi: 10.1245/s10434-023-14319-0

Key clinical point: A majority of patients with metastatic breast cancer (BC) who received alpelisib developed hyperglycemia of any grade, with alpelisib-associated hyperglycemia being more prevalent in standard clinical practice than in clinical trials.

Major finding: Overall, 61.5% of patients developed any-grade hyperglycemia, with the rate being considerably higher in patients who received alpelisib as part of standard care vs clinical trial (80.3% vs 34.0%). Baseline body mass index ≥ 25 kg/m² (P = .036) and A1c levels in the prediabetes and diabetes range (P < .001) were significantly associated with the development of any-grade hyperglycemia.

Study details: Findings are from a retrospective cohort study including 247 patients with metastatic BC who received alpelisib either as standard care (n = 147) or in a clinical trial setting (n = 100).

Disclosures: This work was supported partly by the US National Institutes of Health/National Cancer Institute. Some authors declared receiving honoraria, research funding, or consultant fees from some sources.

Source: Shen S et al. Incidence, risk factors, and management of alpelisib-associated hyperglycemia in metastatic breast cancer. Cancer. 2023 (Sep 25). doi: 10.1002/cncr.34928

Key clinical point: A majority of patients with metastatic breast cancer (BC) who received alpelisib developed hyperglycemia of any grade, with alpelisib-associated hyperglycemia being more prevalent in standard clinical practice than in clinical trials.

Major finding: Overall, 61.5% of patients developed any-grade hyperglycemia, with the rate being considerably higher in patients who received alpelisib as part of standard care vs clinical trial (80.3% vs 34.0%). Baseline body mass index ≥ 25 kg/m² (P = .036) and A1c levels in the prediabetes and diabetes range (P < .001) were significantly associated with the development of any-grade hyperglycemia.

Study details: Findings are from a retrospective cohort study including 247 patients with metastatic BC who received alpelisib either as standard care (n = 147) or in a clinical trial setting (n = 100).

Disclosures: This work was supported partly by the US National Institutes of Health/National Cancer Institute. Some authors declared receiving honoraria, research funding, or consultant fees from some sources.

Source: Shen S et al. Incidence, risk factors, and management of alpelisib-associated hyperglycemia in metastatic breast cancer. Cancer. 2023 (Sep 25). doi: 10.1002/cncr.34928

Key clinical point: A majority of patients with metastatic breast cancer (BC) who received alpelisib developed hyperglycemia of any grade, with alpelisib-associated hyperglycemia being more prevalent in standard clinical practice than in clinical trials.

Major finding: Overall, 61.5% of patients developed any-grade hyperglycemia, with the rate being considerably higher in patients who received alpelisib as part of standard care vs clinical trial (80.3% vs 34.0%). Baseline body mass index ≥ 25 kg/m² (P = .036) and A1c levels in the prediabetes and diabetes range (P < .001) were significantly associated with the development of any-grade hyperglycemia.

Study details: Findings are from a retrospective cohort study including 247 patients with metastatic BC who received alpelisib either as standard care (n = 147) or in a clinical trial setting (n = 100).

Disclosures: This work was supported partly by the US National Institutes of Health/National Cancer Institute. Some authors declared receiving honoraria, research funding, or consultant fees from some sources.

Source: Shen S et al. Incidence, risk factors, and management of alpelisib-associated hyperglycemia in metastatic breast cancer. Cancer. 2023 (Sep 25). doi: 10.1002/cncr.34928

Key clinical point: Chemotherapy-free front-line treatment with dalpiciclib plus pyrotinib demonstrated promising efficacy and manageable safety in patients with human epidermal growth factor receptor 2-positive (HER2+) advanced breast cancer (BC).

Major finding: At a median follow-up of 25.9 months, 28 (70%) patients had a confirmed objective response, with 2 and 26 patients achieving complete and partial responses, respectively. Grades 3 and 4 treatment-related adverse events were reported by 82.9% and 12.2% of patients respectively, and of these, decreased white blood cells, decreased neutrophil count, diarrhea, and anemia were the most common.

Study details: Findings are from a single arm phase 2 study including 41 patients with HER2+ advanced BC who received front-line treatment with dalpiciclib+pyrotinib.

Disclosures: This study was funded by the XINRUI Project of Cancer Supportive Care and Treatment Research, China. H Li declared serving as an employee of Jiangsu Hengrui Pharmaceuticals Co., Ltd. (Shanghai, China) during the study period.

Source: Yan M et al. Dalpiciclib and pyrotinib in women with HER2-positive advanced breast cancer: A single-arm phase II trial. Nat Commun. 2023;14:6272 (Oct 7). doi: 10.1038/s41467-023-41955-7

Key clinical point: Chemotherapy-free front-line treatment with dalpiciclib plus pyrotinib demonstrated promising efficacy and manageable safety in patients with human epidermal growth factor receptor 2-positive (HER2+) advanced breast cancer (BC).

Major finding: At a median follow-up of 25.9 months, 28 (70%) patients had a confirmed objective response, with 2 and 26 patients achieving complete and partial responses, respectively. Grades 3 and 4 treatment-related adverse events were reported by 82.9% and 12.2% of patients respectively, and of these, decreased white blood cells, decreased neutrophil count, diarrhea, and anemia were the most common.

Study details: Findings are from a single arm phase 2 study including 41 patients with HER2+ advanced BC who received front-line treatment with dalpiciclib+pyrotinib.

Disclosures: This study was funded by the XINRUI Project of Cancer Supportive Care and Treatment Research, China. H Li declared serving as an employee of Jiangsu Hengrui Pharmaceuticals Co., Ltd. (Shanghai, China) during the study period.

Source: Yan M et al. Dalpiciclib and pyrotinib in women with HER2-positive advanced breast cancer: A single-arm phase II trial. Nat Commun. 2023;14:6272 (Oct 7). doi: 10.1038/s41467-023-41955-7

Key clinical point: Chemotherapy-free front-line treatment with dalpiciclib plus pyrotinib demonstrated promising efficacy and manageable safety in patients with human epidermal growth factor receptor 2-positive (HER2+) advanced breast cancer (BC).

Major finding: At a median follow-up of 25.9 months, 28 (70%) patients had a confirmed objective response, with 2 and 26 patients achieving complete and partial responses, respectively. Grades 3 and 4 treatment-related adverse events were reported by 82.9% and 12.2% of patients respectively, and of these, decreased white blood cells, decreased neutrophil count, diarrhea, and anemia were the most common.

Study details: Findings are from a single arm phase 2 study including 41 patients with HER2+ advanced BC who received front-line treatment with dalpiciclib+pyrotinib.

Disclosures: This study was funded by the XINRUI Project of Cancer Supportive Care and Treatment Research, China. H Li declared serving as an employee of Jiangsu Hengrui Pharmaceuticals Co., Ltd. (Shanghai, China) during the study period.

Source: Yan M et al. Dalpiciclib and pyrotinib in women with HER2-positive advanced breast cancer: A single-arm phase II trial. Nat Commun. 2023;14:6272 (Oct 7). doi: 10.1038/s41467-023-41955-7

Key clinical point: In patients with breast cancer (BC), hypofractionated proton postmastectomy radiotherapy (PMRT), which is administered in larger doses and fewer sessions, showed similar rates of complications as conventional fractionated proton PMRT.

Major finding: At a median follow-up of 39.3 months, both conventional fractionated and hypofractionated proton PMRT had similar complication rates (15% vs 20%; absolute difference 4.9%; one-sided 95% CI 18.5; P = .27), with all complications occurring in patients with immediate expander or implant-based reconstruction.

Study details: Findings are from the phase 2 MC1631 trial including 82 patients with BC who underwent mastectomy with or without immediate breast reconstruction and were randomly assigned to receive either conventional fractionated (50 Gy in 25 fractions of 2 Gy) or hypofractionated (40.05 Gy in 15 fractions of 2.67 Gy) proton PMRT.

Disclosures: This study was partly supported by Mayo Clinic and other sources. The lead author declared serving as co-chair of the Breast Cancer Subcommittee of the Particle Therapy Cooperative Group.

Source: Mutter RW et al. Conventional versus hypofractionated postmastectomy proton radiotherapy in the USA (MC1631): A randomised phase 2 trial. Lancet Oncol. 2023 24(10):1083-1093 (Sep 8). doi: 10.1016/S1470-2045(23)00388-1

Key clinical point: In patients with breast cancer (BC), hypofractionated proton postmastectomy radiotherapy (PMRT), which is administered in larger doses and fewer sessions, showed similar rates of complications as conventional fractionated proton PMRT.

Major finding: At a median follow-up of 39.3 months, both conventional fractionated and hypofractionated proton PMRT had similar complication rates (15% vs 20%; absolute difference 4.9%; one-sided 95% CI 18.5; P = .27), with all complications occurring in patients with immediate expander or implant-based reconstruction.

Study details: Findings are from the phase 2 MC1631 trial including 82 patients with BC who underwent mastectomy with or without immediate breast reconstruction and were randomly assigned to receive either conventional fractionated (50 Gy in 25 fractions of 2 Gy) or hypofractionated (40.05 Gy in 15 fractions of 2.67 Gy) proton PMRT.

Disclosures: This study was partly supported by Mayo Clinic and other sources. The lead author declared serving as co-chair of the Breast Cancer Subcommittee of the Particle Therapy Cooperative Group.

Source: Mutter RW et al. Conventional versus hypofractionated postmastectomy proton radiotherapy in the USA (MC1631): A randomised phase 2 trial. Lancet Oncol. 2023 24(10):1083-1093 (Sep 8). doi: 10.1016/S1470-2045(23)00388-1

Key clinical point: In patients with breast cancer (BC), hypofractionated proton postmastectomy radiotherapy (PMRT), which is administered in larger doses and fewer sessions, showed similar rates of complications as conventional fractionated proton PMRT.

Major finding: At a median follow-up of 39.3 months, both conventional fractionated and hypofractionated proton PMRT had similar complication rates (15% vs 20%; absolute difference 4.9%; one-sided 95% CI 18.5; P = .27), with all complications occurring in patients with immediate expander or implant-based reconstruction.

Study details: Findings are from the phase 2 MC1631 trial including 82 patients with BC who underwent mastectomy with or without immediate breast reconstruction and were randomly assigned to receive either conventional fractionated (50 Gy in 25 fractions of 2 Gy) or hypofractionated (40.05 Gy in 15 fractions of 2.67 Gy) proton PMRT.

Disclosures: This study was partly supported by Mayo Clinic and other sources. The lead author declared serving as co-chair of the Breast Cancer Subcommittee of the Particle Therapy Cooperative Group.

Source: Mutter RW et al. Conventional versus hypofractionated postmastectomy proton radiotherapy in the USA (MC1631): A randomised phase 2 trial. Lancet Oncol. 2023 24(10):1083-1093 (Sep 8). doi: 10.1016/S1470-2045(23)00388-1

Key clinical point: Postmastectomy breast reconstruction (PMbR) showed breast cancer-specific survival (BCSS) outcomes comparable with those of conventional mastectomy and may be recommended in patients with stage T0-3N2-3M0 non-triple-negative breast cancer (BC).

Major finding: Compared with conventional mastectomy, PMbR did not have any significant detrimental effect on BCSS outcomes (hazard ratio [HR] 0.85; P = .197); however, histopathological grade levels III-IV (HR 3.28; P = .010), T4 stage (HR 3.08; P = .013), and triple-negative BC (HR 4.84; P < .001) were associated with worsened BCSS outcomes in the PMbR group.

Study details: This retrospective study retrieved data from the Surveillance, Epidemiology, and End Results (SEER) database and included 2545 women with N2-3M0 stage BC who underwent either PMbR (n = 761) or conventional mastectomy (n = 1784).

Disclosures: This study was supported by the Clinical Research Program of the first affiliated Hospital of Xi'an Jiaotong University, China, and other sources. The authors declared no conflicts of interest.

Source: Zhao Y, Yan L, et al. Efficacy of breast reconstruction for N2-3M0 stage female breast cancer on breast cancer-specific survival: A population-based propensity score analysis. Cancer Med. 2023 (Oct 5). doi: 10.1002/cam4.6579

Key clinical point: Postmastectomy breast reconstruction (PMbR) showed breast cancer-specific survival (BCSS) outcomes comparable with those of conventional mastectomy and may be recommended in patients with stage T0-3N2-3M0 non-triple-negative breast cancer (BC).

Major finding: Compared with conventional mastectomy, PMbR did not have any significant detrimental effect on BCSS outcomes (hazard ratio [HR] 0.85; P = .197); however, histopathological grade levels III-IV (HR 3.28; P = .010), T4 stage (HR 3.08; P = .013), and triple-negative BC (HR 4.84; P < .001) were associated with worsened BCSS outcomes in the PMbR group.

Study details: This retrospective study retrieved data from the Surveillance, Epidemiology, and End Results (SEER) database and included 2545 women with N2-3M0 stage BC who underwent either PMbR (n = 761) or conventional mastectomy (n = 1784).

Disclosures: This study was supported by the Clinical Research Program of the first affiliated Hospital of Xi'an Jiaotong University, China, and other sources. The authors declared no conflicts of interest.

Source: Zhao Y, Yan L, et al. Efficacy of breast reconstruction for N2-3M0 stage female breast cancer on breast cancer-specific survival: A population-based propensity score analysis. Cancer Med. 2023 (Oct 5). doi: 10.1002/cam4.6579

Key clinical point: Postmastectomy breast reconstruction (PMbR) showed breast cancer-specific survival (BCSS) outcomes comparable with those of conventional mastectomy and may be recommended in patients with stage T0-3N2-3M0 non-triple-negative breast cancer (BC).

Major finding: Compared with conventional mastectomy, PMbR did not have any significant detrimental effect on BCSS outcomes (hazard ratio [HR] 0.85; P = .197); however, histopathological grade levels III-IV (HR 3.28; P = .010), T4 stage (HR 3.08; P = .013), and triple-negative BC (HR 4.84; P < .001) were associated with worsened BCSS outcomes in the PMbR group.

Study details: This retrospective study retrieved data from the Surveillance, Epidemiology, and End Results (SEER) database and included 2545 women with N2-3M0 stage BC who underwent either PMbR (n = 761) or conventional mastectomy (n = 1784).

Disclosures: This study was supported by the Clinical Research Program of the first affiliated Hospital of Xi'an Jiaotong University, China, and other sources. The authors declared no conflicts of interest.

Source: Zhao Y, Yan L, et al. Efficacy of breast reconstruction for N2-3M0 stage female breast cancer on breast cancer-specific survival: A population-based propensity score analysis. Cancer Med. 2023 (Oct 5). doi: 10.1002/cam4.6579

Key clinical point: Human epidermal growth factor receptor 2 (HER2)-low vs HER2-0 expression was associated with improved breast cancer-specific survival (BCSS) outcomes in patients with early-stage triple-negative breast cancer (TNBC), particularly in the high-risk subgroups.

Major finding: Patients with HER2-low vs HER2-0 BC had significantly better BCSS rates in the overall population (96.6% vs 93.7%; log-rank P = .027) and in high-risk subpopulations comprising patients without a pathological complete response despite neoadjuvant chemotherapy (log-rank P = .047) or those with stage-III BC (log-rank P = .010).

Study details: Findings are from a study including 1445 female patients with early-stage TNBC, of whom 51.7% and 48.3% showed HER2-0 and HER2-low status, respectively.

Disclosures: This study was sponsored by the Health Commission of Henan Province, China. The authors declared no conflicts of interest.

Source: Ma Y et al. HER2-low status was associated with better breast cancer-specific survival in early-stage triple-negative breast cancer. Oncologist. 2023 (Sep 28). doi: 10.1093/oncolo/oyad275

Key clinical point: Human epidermal growth factor receptor 2 (HER2)-low vs HER2-0 expression was associated with improved breast cancer-specific survival (BCSS) outcomes in patients with early-stage triple-negative breast cancer (TNBC), particularly in the high-risk subgroups.

Major finding: Patients with HER2-low vs HER2-0 BC had significantly better BCSS rates in the overall population (96.6% vs 93.7%; log-rank P = .027) and in high-risk subpopulations comprising patients without a pathological complete response despite neoadjuvant chemotherapy (log-rank P = .047) or those with stage-III BC (log-rank P = .010).

Study details: Findings are from a study including 1445 female patients with early-stage TNBC, of whom 51.7% and 48.3% showed HER2-0 and HER2-low status, respectively.

Disclosures: This study was sponsored by the Health Commission of Henan Province, China. The authors declared no conflicts of interest.

Source: Ma Y et al. HER2-low status was associated with better breast cancer-specific survival in early-stage triple-negative breast cancer. Oncologist. 2023 (Sep 28). doi: 10.1093/oncolo/oyad275

Key clinical point: Human epidermal growth factor receptor 2 (HER2)-low vs HER2-0 expression was associated with improved breast cancer-specific survival (BCSS) outcomes in patients with early-stage triple-negative breast cancer (TNBC), particularly in the high-risk subgroups.

Major finding: Patients with HER2-low vs HER2-0 BC had significantly better BCSS rates in the overall population (96.6% vs 93.7%; log-rank P = .027) and in high-risk subpopulations comprising patients without a pathological complete response despite neoadjuvant chemotherapy (log-rank P = .047) or those with stage-III BC (log-rank P = .010).

Study details: Findings are from a study including 1445 female patients with early-stage TNBC, of whom 51.7% and 48.3% showed HER2-0 and HER2-low status, respectively.

Disclosures: This study was sponsored by the Health Commission of Henan Province, China. The authors declared no conflicts of interest.

Source: Ma Y et al. HER2-low status was associated with better breast cancer-specific survival in early-stage triple-negative breast cancer. Oncologist. 2023 (Sep 28). doi: 10.1093/oncolo/oyad275

Key clinical point: This real-world study confirmed the effectiveness of tucatinib across all treatment lines in patients with human epidermal growth factor receptor 2-positive (HER2+) metastatic breast cancer (BC).

Major finding: Median real-world time-to-treatment discontinuation was 6.5 months (95% CI 5.4-8.8 months) for the overall population but was longer in patients who received tucatinib in combination with trastuzumab and capecitabine in a metastatic setting (8.1 months; 95% CI 5.7-9.5 months) or as second-line or third-line therapy (9.4 months; 95% CI 6.3-14.1 months). Median real-world overall survival was 26.6 months (95% CI 20.2-not reached).

Study details: Findings are from a retrospective cohort study including 216 patients with HER2+ metastatic BC who received tucatinib in any line of therapy.

Disclosures: This study was sponsored by Seagen Inc. and Merck Sharp & Dohme LLC. Seven authors declared being employees of and holding stock or stock options in Seagen Inc., and the other authors declared ties with various sources, including Seagen and Merck Sharp & Dohme.

Source: Kaufman PA et al. Real-world patient characteristics, treatment patterns, and clinical outcomes associated with tucatinib therapy in HER2-positive metastatic breast cancer. Front Oncol. 2023;13:1264861 (Oct 2). doi: 10.3389/fonc.2023.1264861

Key clinical point: This real-world study confirmed the effectiveness of tucatinib across all treatment lines in patients with human epidermal growth factor receptor 2-positive (HER2+) metastatic breast cancer (BC).

Major finding: Median real-world time-to-treatment discontinuation was 6.5 months (95% CI 5.4-8.8 months) for the overall population but was longer in patients who received tucatinib in combination with trastuzumab and capecitabine in a metastatic setting (8.1 months; 95% CI 5.7-9.5 months) or as second-line or third-line therapy (9.4 months; 95% CI 6.3-14.1 months). Median real-world overall survival was 26.6 months (95% CI 20.2-not reached).

Study details: Findings are from a retrospective cohort study including 216 patients with HER2+ metastatic BC who received tucatinib in any line of therapy.

Disclosures: This study was sponsored by Seagen Inc. and Merck Sharp & Dohme LLC. Seven authors declared being employees of and holding stock or stock options in Seagen Inc., and the other authors declared ties with various sources, including Seagen and Merck Sharp & Dohme.

Source: Kaufman PA et al. Real-world patient characteristics, treatment patterns, and clinical outcomes associated with tucatinib therapy in HER2-positive metastatic breast cancer. Front Oncol. 2023;13:1264861 (Oct 2). doi: 10.3389/fonc.2023.1264861

Key clinical point: This real-world study confirmed the effectiveness of tucatinib across all treatment lines in patients with human epidermal growth factor receptor 2-positive (HER2+) metastatic breast cancer (BC).

Major finding: Median real-world time-to-treatment discontinuation was 6.5 months (95% CI 5.4-8.8 months) for the overall population but was longer in patients who received tucatinib in combination with trastuzumab and capecitabine in a metastatic setting (8.1 months; 95% CI 5.7-9.5 months) or as second-line or third-line therapy (9.4 months; 95% CI 6.3-14.1 months). Median real-world overall survival was 26.6 months (95% CI 20.2-not reached).

Study details: Findings are from a retrospective cohort study including 216 patients with HER2+ metastatic BC who received tucatinib in any line of therapy.

Disclosures: This study was sponsored by Seagen Inc. and Merck Sharp & Dohme LLC. Seven authors declared being employees of and holding stock or stock options in Seagen Inc., and the other authors declared ties with various sources, including Seagen and Merck Sharp & Dohme.

Source: Kaufman PA et al. Real-world patient characteristics, treatment patterns, and clinical outcomes associated with tucatinib therapy in HER2-positive metastatic breast cancer. Front Oncol. 2023;13:1264861 (Oct 2). doi: 10.3389/fonc.2023.1264861

Key clinical point: Unlike partial breast irradiation (PBI), intraoperative radiation therapy (IORT) was associated with higher ipsilateral breast tumor recurrence (IBTR) rates than whole breast irradiation (WBI) in patients with early-stage breast cancer (BC) who underwent breast-conserving surgery (BCS).

Major finding: The risk for IBTR was comparable in patients treated with PBI and WBI (hazard ratio [HR] 1.20; P = .12) but was significantly higher in patients treated with IORT vs WBI (HR 1.46; P < .01).

Study details: Findings are from a meta-analysis of 11 randomized controlled trials including 15,460 patients with early-stage BC who underwent BCS, of whom 7190 patients, 4931 patients, and 2372 patients received WBI, PBI, and IORT, respectively.

Disclosures: This study did not receive any specific funding. Some authors declared serving as consultants for or receiving grants from various sources.

Source: Ravani LV et al. Comparison of partial-breast irradiation and intraoperative radiation to whole-breast irradiation in early-stage breast cancer patients: A Kaplan-Meier-derived patient data meta-analysis. Breast Cancer Res Treat. 2023 (Sep 22). doi: 10.1007/s10549-023-07112-w

Key clinical point: Unlike partial breast irradiation (PBI), intraoperative radiation therapy (IORT) was associated with higher ipsilateral breast tumor recurrence (IBTR) rates than whole breast irradiation (WBI) in patients with early-stage breast cancer (BC) who underwent breast-conserving surgery (BCS).

Major finding: The risk for IBTR was comparable in patients treated with PBI and WBI (hazard ratio [HR] 1.20; P = .12) but was significantly higher in patients treated with IORT vs WBI (HR 1.46; P < .01).

Study details: Findings are from a meta-analysis of 11 randomized controlled trials including 15,460 patients with early-stage BC who underwent BCS, of whom 7190 patients, 4931 patients, and 2372 patients received WBI, PBI, and IORT, respectively.

Disclosures: This study did not receive any specific funding. Some authors declared serving as consultants for or receiving grants from various sources.

Source: Ravani LV et al. Comparison of partial-breast irradiation and intraoperative radiation to whole-breast irradiation in early-stage breast cancer patients: A Kaplan-Meier-derived patient data meta-analysis. Breast Cancer Res Treat. 2023 (Sep 22). doi: 10.1007/s10549-023-07112-w

Key clinical point: Unlike partial breast irradiation (PBI), intraoperative radiation therapy (IORT) was associated with higher ipsilateral breast tumor recurrence (IBTR) rates than whole breast irradiation (WBI) in patients with early-stage breast cancer (BC) who underwent breast-conserving surgery (BCS).

Major finding: The risk for IBTR was comparable in patients treated with PBI and WBI (hazard ratio [HR] 1.20; P = .12) but was significantly higher in patients treated with IORT vs WBI (HR 1.46; P < .01).

Study details: Findings are from a meta-analysis of 11 randomized controlled trials including 15,460 patients with early-stage BC who underwent BCS, of whom 7190 patients, 4931 patients, and 2372 patients received WBI, PBI, and IORT, respectively.

Disclosures: This study did not receive any specific funding. Some authors declared serving as consultants for or receiving grants from various sources.

Source: Ravani LV et al. Comparison of partial-breast irradiation and intraoperative radiation to whole-breast irradiation in early-stage breast cancer patients: A Kaplan-Meier-derived patient data meta-analysis. Breast Cancer Res Treat. 2023 (Sep 22). doi: 10.1007/s10549-023-07112-w

Key clinical point: Compared with good or low adherence to adjuvant hormone therapy (HT), excellent adherence was associated with a significantly reduced risk for subsequent breast tumors (SBT) in older women with ductal carcinoma in situ (DCIS) of the breast.

Major finding: In patients with excellent vs low adherence to adjuvant HT, both breast-conserving surgery (BCS) and BCS + radiation therapy (RT) significantly reduced the risks for SBT (−10.54 and −6.24 percentage points, respectively; both P < .00001) or subsequent invasive breast cancer (−8.85 and −4.28 percentage points, respectively; both P < .00001). Similar results were obtained in patients with excellent vs good adherence to adjuvant HT.

Study details: Findings are from an analysis of a population-based study including 3075 women with DCIS who were age ≥ 65 years and underwent BCS either with (75%) or without RT (25%).

Disclosures: This study was supported by the US National Cancer Institute. Two authors declared serving as consultants for various sources.

Source: Mitchell JM et al. Adherence to hormonal therapy after surgery among older women with ductal carcinoma in situ: Implications for breast cancer-related adverse health events. Cancer. 2023 (Sep 26). Doi: 10.1002/cncr.35009

Key clinical point: Compared with good or low adherence to adjuvant hormone therapy (HT), excellent adherence was associated with a significantly reduced risk for subsequent breast tumors (SBT) in older women with ductal carcinoma in situ (DCIS) of the breast.

Major finding: In patients with excellent vs low adherence to adjuvant HT, both breast-conserving surgery (BCS) and BCS + radiation therapy (RT) significantly reduced the risks for SBT (−10.54 and −6.24 percentage points, respectively; both P < .00001) or subsequent invasive breast cancer (−8.85 and −4.28 percentage points, respectively; both P < .00001). Similar results were obtained in patients with excellent vs good adherence to adjuvant HT.

Study details: Findings are from an analysis of a population-based study including 3075 women with DCIS who were age ≥ 65 years and underwent BCS either with (75%) or without RT (25%).

Disclosures: This study was supported by the US National Cancer Institute. Two authors declared serving as consultants for various sources.

Source: Mitchell JM et al. Adherence to hormonal therapy after surgery among older women with ductal carcinoma in situ: Implications for breast cancer-related adverse health events. Cancer. 2023 (Sep 26). Doi: 10.1002/cncr.35009

Key clinical point: Compared with good or low adherence to adjuvant hormone therapy (HT), excellent adherence was associated with a significantly reduced risk for subsequent breast tumors (SBT) in older women with ductal carcinoma in situ (DCIS) of the breast.

Major finding: In patients with excellent vs low adherence to adjuvant HT, both breast-conserving surgery (BCS) and BCS + radiation therapy (RT) significantly reduced the risks for SBT (−10.54 and −6.24 percentage points, respectively; both P < .00001) or subsequent invasive breast cancer (−8.85 and −4.28 percentage points, respectively; both P < .00001). Similar results were obtained in patients with excellent vs good adherence to adjuvant HT.

Study details: Findings are from an analysis of a population-based study including 3075 women with DCIS who were age ≥ 65 years and underwent BCS either with (75%) or without RT (25%).

Disclosures: This study was supported by the US National Cancer Institute. Two authors declared serving as consultants for various sources.

Source: Mitchell JM et al. Adherence to hormonal therapy after surgery among older women with ductal carcinoma in situ: Implications for breast cancer-related adverse health events. Cancer. 2023 (Sep 26). Doi: 10.1002/cncr.35009