Michelle Andrews

For many patients, seeing a nurse practitioner has become a routine part of primary care, in which these “NPs” often perform the same tasks that patients have relied on doctors for.

But NPs in specialty care? That’s not routine, at least not yet. Increasingly, though, nurse practitioners and physician assistants are joining cardiology, dermatology, and other specialty practices, broadening their skills and increasing their income.

This development worries some people who track the health workforce, because current trends suggest primary care, which has counted on nurse practitioners to backstop physician shortages, soon might not be able to rely on them to the same extent.

“They’re succumbing to the same challenges that we have with physicians,” said Atul Grover, MD, PhD, executive director of the Research and Action Institute at the Association of American Medical Colleges. The rates NPs can command in a specialty practice “are quite a bit higher” than practice salaries in primary care, he said.

When nurse practitioner programs began to proliferate in the 1970s, “at first it looked great, producing all these nurse practitioners that go to work with primary care physicians,” said Yalda Jabbarpour, MD, director of the American Academy of Family Physicians’ Robert Graham Center for Policy Studies. “But now only 30% are going into primary care.”

Dr. Jabbarpour was referring to the 2024 primary care scorecard by the Milbank Memorial Fund, which found that from 2016 to 2021 the proportion of nurse practitioners who worked in primary care practices hovered between 32% and 34%, even though their numbers grew rapidly. The proportion of physician assistants, also known as physician associates, in primary care ranged from 27% to 30%, the study found.

Both nurse practitioners and physician assistants are advanced practice clinicians who, in addition to graduate degrees, must complete distinct education, training, and certification steps. NPs can practice without a doctor’s supervision in more than two dozen states, while PAs have similar independence in only a handful of states.

About 88% of nurse practitioners are certified in an area of primary care, according to the American Association of Nurse Practitioners. But it is difficult to track exactly how many work in primary care or in specialty practices. Unlike physicians, they’re generally not required to be endorsed by a national standard-setting body to practice in specialties like oncology or cardiology, for example. The AANP declined to answer questions about its annual workforce survey or the extent to which primary care NPs are moving toward specialties.

Though data tracking the change is sparse, specialty practices are adding these advanced practice clinicians at almost the same rate as primary care practices, according to frequently cited research published in 2018.

The clearest evidence of the shift: From 2008 to 2016, there was a 22% increase in the number of specialty practices that employed nurse practitioners and physician assistants, according to that study. The increase in the number of primary care practices that employed these professionals was 24%.

Once more, the most recent projections by the Association of American Medical Colleges predict a dearth of at least 20,200 primary care physicians by 2036. There will also be a shortfall of non-primary care specialists, including a deficiency of at least 10,100 surgical physicians and up to 25,000 physicians in other specialties.

When it comes to the actual work performed, the lines between primary and specialty care are often blurred, said Candice Chen, MD, MPH, associate professor of health policy and management at George Washington University.

“You might be a nurse practitioner working in a gastroenterology clinic or cardiology clinic, but the scope of what you do is starting to overlap with primary care,” she said.

Nurse practitioners’ salaries vary widely by location, type of facility, and experience. Still, according to data from health care recruiter AMN Healthcare Physician Solutions, formerly known as Merritt Hawkins, the total annual average starting compensation, including signing bonus, for nurse practitioners and physician assistants in specialty practice was $172,544 in the year that ended March 31, slightly higher than the $166,544 for those in primary care.

According to forecasts from the federal Bureau of Labor Statistics, nurse practitioner jobs will increase faster than jobs in almost any other occupation in the decade leading up to 2032, growing by 123,600 jobs or 45%. (Wind turbine service technician is the only other occupation projected to grow as fast.) The growth rate for physician assistants is also much faster than average, at 27%. There are more than twice as many nurse practitioners as physician assistants, however: 323,900 versus 148,000, in 2022.

To Dr. Grover of the AAMC, numbers like this signal that there will probably be enough NPs, PAs, and physicians to meet primary care needs. At the same time, “expect more NPs and PAs to also flow out into other specialties,” he said.

When Pamela Ograbisz started working as a registered nurse 27 years ago, she worked in a cardiothoracic intensive care unit. After she became a family nurse practitioner a few years later, she found a job with a similar specialty practice, which trained her to take on a bigger role, first running their outpatient clinic, then working on the floor, and later in the intensive care unit.

If nurse practitioners want to specialize, often “the doctors mentor them just like they would with a physician residency,” said Ms. Ograbisz, now vice president of clinical operations at temporary placement recruiter LocumTenens.com.

If physician assistants want to specialize, they also can do so through mentoring, or they can receive “certificates of added qualifications” in 10 specialties to demonstrate their expertise. Most employers don’t “encourage or require” these certificates, however, said Jennifer Orozco, DMSc, PA-C, DFAAPA, chief medical officer at the American Academy of Physician Associates.

There are a number of training programs for family nurse practitioners who want to develop skills in other areas.

Raina Hoebelheinrich, 40, a family nurse practitioner at a regional medical center in Yankton, South Dakota, recently enrolled in a three-semester post-master’s endocrinology training program at Mount Marty University. She lives on a farm in nearby northeastern Nebraska with her husband and five sons.

Ms. Hoebelheinrich’s new skills could be helpful in her current hospital job, in which she sees a lot of patients with acute diabetes, or in a clinic setting like the one in Sioux Falls, South Dakota, where she is doing her clinical endocrinology training.

Lack of access to endocrinology care in rural areas is a real problem, and many people may travel hundreds of miles to see a specialist.

“There aren’t a lot of options,” she said.

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

For many patients, seeing a nurse practitioner has become a routine part of primary care, in which these “NPs” often perform the same tasks that patients have relied on doctors for.

But NPs in specialty care? That’s not routine, at least not yet. Increasingly, though, nurse practitioners and physician assistants are joining cardiology, dermatology, and other specialty practices, broadening their skills and increasing their income.

This development worries some people who track the health workforce, because current trends suggest primary care, which has counted on nurse practitioners to backstop physician shortages, soon might not be able to rely on them to the same extent.

“They’re succumbing to the same challenges that we have with physicians,” said Atul Grover, MD, PhD, executive director of the Research and Action Institute at the Association of American Medical Colleges. The rates NPs can command in a specialty practice “are quite a bit higher” than practice salaries in primary care, he said.

When nurse practitioner programs began to proliferate in the 1970s, “at first it looked great, producing all these nurse practitioners that go to work with primary care physicians,” said Yalda Jabbarpour, MD, director of the American Academy of Family Physicians’ Robert Graham Center for Policy Studies. “But now only 30% are going into primary care.”

Dr. Jabbarpour was referring to the 2024 primary care scorecard by the Milbank Memorial Fund, which found that from 2016 to 2021 the proportion of nurse practitioners who worked in primary care practices hovered between 32% and 34%, even though their numbers grew rapidly. The proportion of physician assistants, also known as physician associates, in primary care ranged from 27% to 30%, the study found.

Both nurse practitioners and physician assistants are advanced practice clinicians who, in addition to graduate degrees, must complete distinct education, training, and certification steps. NPs can practice without a doctor’s supervision in more than two dozen states, while PAs have similar independence in only a handful of states.

About 88% of nurse practitioners are certified in an area of primary care, according to the American Association of Nurse Practitioners. But it is difficult to track exactly how many work in primary care or in specialty practices. Unlike physicians, they’re generally not required to be endorsed by a national standard-setting body to practice in specialties like oncology or cardiology, for example. The AANP declined to answer questions about its annual workforce survey or the extent to which primary care NPs are moving toward specialties.

Though data tracking the change is sparse, specialty practices are adding these advanced practice clinicians at almost the same rate as primary care practices, according to frequently cited research published in 2018.

The clearest evidence of the shift: From 2008 to 2016, there was a 22% increase in the number of specialty practices that employed nurse practitioners and physician assistants, according to that study. The increase in the number of primary care practices that employed these professionals was 24%.

Once more, the most recent projections by the Association of American Medical Colleges predict a dearth of at least 20,200 primary care physicians by 2036. There will also be a shortfall of non-primary care specialists, including a deficiency of at least 10,100 surgical physicians and up to 25,000 physicians in other specialties.

When it comes to the actual work performed, the lines between primary and specialty care are often blurred, said Candice Chen, MD, MPH, associate professor of health policy and management at George Washington University.

“You might be a nurse practitioner working in a gastroenterology clinic or cardiology clinic, but the scope of what you do is starting to overlap with primary care,” she said.

Nurse practitioners’ salaries vary widely by location, type of facility, and experience. Still, according to data from health care recruiter AMN Healthcare Physician Solutions, formerly known as Merritt Hawkins, the total annual average starting compensation, including signing bonus, for nurse practitioners and physician assistants in specialty practice was $172,544 in the year that ended March 31, slightly higher than the $166,544 for those in primary care.

According to forecasts from the federal Bureau of Labor Statistics, nurse practitioner jobs will increase faster than jobs in almost any other occupation in the decade leading up to 2032, growing by 123,600 jobs or 45%. (Wind turbine service technician is the only other occupation projected to grow as fast.) The growth rate for physician assistants is also much faster than average, at 27%. There are more than twice as many nurse practitioners as physician assistants, however: 323,900 versus 148,000, in 2022.

To Dr. Grover of the AAMC, numbers like this signal that there will probably be enough NPs, PAs, and physicians to meet primary care needs. At the same time, “expect more NPs and PAs to also flow out into other specialties,” he said.

When Pamela Ograbisz started working as a registered nurse 27 years ago, she worked in a cardiothoracic intensive care unit. After she became a family nurse practitioner a few years later, she found a job with a similar specialty practice, which trained her to take on a bigger role, first running their outpatient clinic, then working on the floor, and later in the intensive care unit.

If nurse practitioners want to specialize, often “the doctors mentor them just like they would with a physician residency,” said Ms. Ograbisz, now vice president of clinical operations at temporary placement recruiter LocumTenens.com.

If physician assistants want to specialize, they also can do so through mentoring, or they can receive “certificates of added qualifications” in 10 specialties to demonstrate their expertise. Most employers don’t “encourage or require” these certificates, however, said Jennifer Orozco, DMSc, PA-C, DFAAPA, chief medical officer at the American Academy of Physician Associates.

There are a number of training programs for family nurse practitioners who want to develop skills in other areas.

Raina Hoebelheinrich, 40, a family nurse practitioner at a regional medical center in Yankton, South Dakota, recently enrolled in a three-semester post-master’s endocrinology training program at Mount Marty University. She lives on a farm in nearby northeastern Nebraska with her husband and five sons.

Ms. Hoebelheinrich’s new skills could be helpful in her current hospital job, in which she sees a lot of patients with acute diabetes, or in a clinic setting like the one in Sioux Falls, South Dakota, where she is doing her clinical endocrinology training.

Lack of access to endocrinology care in rural areas is a real problem, and many people may travel hundreds of miles to see a specialist.

“There aren’t a lot of options,” she said.

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

For many patients, seeing a nurse practitioner has become a routine part of primary care, in which these “NPs” often perform the same tasks that patients have relied on doctors for.

But NPs in specialty care? That’s not routine, at least not yet. Increasingly, though, nurse practitioners and physician assistants are joining cardiology, dermatology, and other specialty practices, broadening their skills and increasing their income.

This development worries some people who track the health workforce, because current trends suggest primary care, which has counted on nurse practitioners to backstop physician shortages, soon might not be able to rely on them to the same extent.

“They’re succumbing to the same challenges that we have with physicians,” said Atul Grover, MD, PhD, executive director of the Research and Action Institute at the Association of American Medical Colleges. The rates NPs can command in a specialty practice “are quite a bit higher” than practice salaries in primary care, he said.

When nurse practitioner programs began to proliferate in the 1970s, “at first it looked great, producing all these nurse practitioners that go to work with primary care physicians,” said Yalda Jabbarpour, MD, director of the American Academy of Family Physicians’ Robert Graham Center for Policy Studies. “But now only 30% are going into primary care.”

Dr. Jabbarpour was referring to the 2024 primary care scorecard by the Milbank Memorial Fund, which found that from 2016 to 2021 the proportion of nurse practitioners who worked in primary care practices hovered between 32% and 34%, even though their numbers grew rapidly. The proportion of physician assistants, also known as physician associates, in primary care ranged from 27% to 30%, the study found.

Both nurse practitioners and physician assistants are advanced practice clinicians who, in addition to graduate degrees, must complete distinct education, training, and certification steps. NPs can practice without a doctor’s supervision in more than two dozen states, while PAs have similar independence in only a handful of states.

About 88% of nurse practitioners are certified in an area of primary care, according to the American Association of Nurse Practitioners. But it is difficult to track exactly how many work in primary care or in specialty practices. Unlike physicians, they’re generally not required to be endorsed by a national standard-setting body to practice in specialties like oncology or cardiology, for example. The AANP declined to answer questions about its annual workforce survey or the extent to which primary care NPs are moving toward specialties.

Though data tracking the change is sparse, specialty practices are adding these advanced practice clinicians at almost the same rate as primary care practices, according to frequently cited research published in 2018.

The clearest evidence of the shift: From 2008 to 2016, there was a 22% increase in the number of specialty practices that employed nurse practitioners and physician assistants, according to that study. The increase in the number of primary care practices that employed these professionals was 24%.

Once more, the most recent projections by the Association of American Medical Colleges predict a dearth of at least 20,200 primary care physicians by 2036. There will also be a shortfall of non-primary care specialists, including a deficiency of at least 10,100 surgical physicians and up to 25,000 physicians in other specialties.

When it comes to the actual work performed, the lines between primary and specialty care are often blurred, said Candice Chen, MD, MPH, associate professor of health policy and management at George Washington University.

“You might be a nurse practitioner working in a gastroenterology clinic or cardiology clinic, but the scope of what you do is starting to overlap with primary care,” she said.

Nurse practitioners’ salaries vary widely by location, type of facility, and experience. Still, according to data from health care recruiter AMN Healthcare Physician Solutions, formerly known as Merritt Hawkins, the total annual average starting compensation, including signing bonus, for nurse practitioners and physician assistants in specialty practice was $172,544 in the year that ended March 31, slightly higher than the $166,544 for those in primary care.

According to forecasts from the federal Bureau of Labor Statistics, nurse practitioner jobs will increase faster than jobs in almost any other occupation in the decade leading up to 2032, growing by 123,600 jobs or 45%. (Wind turbine service technician is the only other occupation projected to grow as fast.) The growth rate for physician assistants is also much faster than average, at 27%. There are more than twice as many nurse practitioners as physician assistants, however: 323,900 versus 148,000, in 2022.

To Dr. Grover of the AAMC, numbers like this signal that there will probably be enough NPs, PAs, and physicians to meet primary care needs. At the same time, “expect more NPs and PAs to also flow out into other specialties,” he said.

When Pamela Ograbisz started working as a registered nurse 27 years ago, she worked in a cardiothoracic intensive care unit. After she became a family nurse practitioner a few years later, she found a job with a similar specialty practice, which trained her to take on a bigger role, first running their outpatient clinic, then working on the floor, and later in the intensive care unit.

If nurse practitioners want to specialize, often “the doctors mentor them just like they would with a physician residency,” said Ms. Ograbisz, now vice president of clinical operations at temporary placement recruiter LocumTenens.com.

If physician assistants want to specialize, they also can do so through mentoring, or they can receive “certificates of added qualifications” in 10 specialties to demonstrate their expertise. Most employers don’t “encourage or require” these certificates, however, said Jennifer Orozco, DMSc, PA-C, DFAAPA, chief medical officer at the American Academy of Physician Associates.

There are a number of training programs for family nurse practitioners who want to develop skills in other areas.

Raina Hoebelheinrich, 40, a family nurse practitioner at a regional medical center in Yankton, South Dakota, recently enrolled in a three-semester post-master’s endocrinology training program at Mount Marty University. She lives on a farm in nearby northeastern Nebraska with her husband and five sons.

Ms. Hoebelheinrich’s new skills could be helpful in her current hospital job, in which she sees a lot of patients with acute diabetes, or in a clinic setting like the one in Sioux Falls, South Dakota, where she is doing her clinical endocrinology training.

Lack of access to endocrinology care in rural areas is a real problem, and many people may travel hundreds of miles to see a specialist.

“There aren’t a lot of options,” she said.

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

When Katie Couric shared the news of her breast cancer diagnosis, the former co-host of NBC’s “Today” show said she considered this new health challenge to be a teachable moment to encourage people to get needed cancer screenings.

“Please get your annual mammogram,” she wrote on her website in September. “But just as importantly, please find out if you need additional screening.”

In the essay, Couric, 65, explained that because she tends to have dense breast tissue, she gets an ultrasound test in addition to a mammogram when screening for breast cancer. A breast ultrasound, sometimes called a sonogram, uses sound waves to take images of the breast tissue. It can sometimes identify malignancies that are hard to spot on a mammogram in women whose breasts are dense – that is, having a high proportion of fibrous tissue and glands vs. fatty tissue.

Ms. Couric, who famously underwent a colonoscopy on live television after her first husband died of colon cancer and who lost her sister to pancreatic cancer, has long pushed for cancer screening and better detection options.

Breast cancer experts applauded Ms. Couric for drawing attention to breast density as a risk factor for cancer. But some were less comfortable with her advocacy for supplemental screening.

“We don’t have evidence that auxiliary screening reduces breast cancer mortality or improves quality of life,” said Dr. Carol Mangione, a professor of medicine and public health at the University of California, Los Angeles, who chairs the U.S. Preventive Services Task Force, a group of medical experts who make recommendations for preventive services after weighing their benefits and harms.

Ms. Couric’s office did not respond to requests for comment.

In addition to an annual mammogram, some women with dense breasts get a breast ultrasound or MRI to help identify cancerous cells missed by the mammogram. Dense fibrous tissue appears white on a mammogram and makes it harder to see cancers, which also appear white. Fatty breast tissue, which appears dark on the mammogram, doesn’t obscure breast malignancies.

As digital breast tomosynthesis, or 3-D mammography, has become more widely available, a growing number of women are getting that screening test rather than the standard 2-D mammography. The 3-D mammography has been found to reduce the number of false-positive results and identify more cancers in some women with dense breasts, though the impact on mortality is unknown.

The task force gives an “I” rating to supplemental screening for women with dense breasts whose mammogram results don’t indicate a problem. That means the current evidence is “insufficient” to assess whether the benefits outweigh the harms of the extra screening. (The task force is updating its recommendation for breast cancer screening, including supplemental screening for women with dense breasts.)

One key harm that researchers are concerned about, besides the possible extra cost, is the chance of a false-positive result. Supplemental imaging in women who aren’t at high risk for breast cancer may identify potential trouble spots, which can lead to follow-up testing such as breast biopsies that are invasive and raise cancer fears for many patients. But research has found that very often these results turn out to be false alarms.

If 1,000 women with dense breasts get an ultrasound after a negative mammogram, the ultrasound will identify two to three cancers, studies show. But the extra imaging will also identify up to 117 potential problems that lead to recall visits and tests but are ultimately determined to be false positives.

“On the one hand, we want to do everything we can to improve detection,” said Dr. Sharon Mass, an ob.gyn. in Morristown, N.J., and the former chair of the American College of Obstetricians and Gynecologists’ New Jersey section. “But on the other hand, there are lots of costs and emotional distress” associated with false-positive results.

The professional group doesn’t recommend supplemental screening for women with dense breasts who don’t have any additional risk factors for cancer.

Many other professional groups take a similar position.

“We recommend having a conversation with a health care provider, and for patients to understand whether their breasts are dense,” Dr. Mass said. “But we do not recommend everyone get tested.”

KHN (Kaiser Health News) is a national newsroom that produces in-depth journalism about health issues. Together with Policy Analysis and Polling, KHN is one of the three major operating programs at KFF (Kaiser Family Foundation). KFF is an endowed nonprofit organization providing information on health issues to the nation.

When Katie Couric shared the news of her breast cancer diagnosis, the former co-host of NBC’s “Today” show said she considered this new health challenge to be a teachable moment to encourage people to get needed cancer screenings.

“Please get your annual mammogram,” she wrote on her website in September. “But just as importantly, please find out if you need additional screening.”

In the essay, Couric, 65, explained that because she tends to have dense breast tissue, she gets an ultrasound test in addition to a mammogram when screening for breast cancer. A breast ultrasound, sometimes called a sonogram, uses sound waves to take images of the breast tissue. It can sometimes identify malignancies that are hard to spot on a mammogram in women whose breasts are dense – that is, having a high proportion of fibrous tissue and glands vs. fatty tissue.

Ms. Couric, who famously underwent a colonoscopy on live television after her first husband died of colon cancer and who lost her sister to pancreatic cancer, has long pushed for cancer screening and better detection options.

Breast cancer experts applauded Ms. Couric for drawing attention to breast density as a risk factor for cancer. But some were less comfortable with her advocacy for supplemental screening.

“We don’t have evidence that auxiliary screening reduces breast cancer mortality or improves quality of life,” said Dr. Carol Mangione, a professor of medicine and public health at the University of California, Los Angeles, who chairs the U.S. Preventive Services Task Force, a group of medical experts who make recommendations for preventive services after weighing their benefits and harms.

Ms. Couric’s office did not respond to requests for comment.

In addition to an annual mammogram, some women with dense breasts get a breast ultrasound or MRI to help identify cancerous cells missed by the mammogram. Dense fibrous tissue appears white on a mammogram and makes it harder to see cancers, which also appear white. Fatty breast tissue, which appears dark on the mammogram, doesn’t obscure breast malignancies.

As digital breast tomosynthesis, or 3-D mammography, has become more widely available, a growing number of women are getting that screening test rather than the standard 2-D mammography. The 3-D mammography has been found to reduce the number of false-positive results and identify more cancers in some women with dense breasts, though the impact on mortality is unknown.

The task force gives an “I” rating to supplemental screening for women with dense breasts whose mammogram results don’t indicate a problem. That means the current evidence is “insufficient” to assess whether the benefits outweigh the harms of the extra screening. (The task force is updating its recommendation for breast cancer screening, including supplemental screening for women with dense breasts.)

One key harm that researchers are concerned about, besides the possible extra cost, is the chance of a false-positive result. Supplemental imaging in women who aren’t at high risk for breast cancer may identify potential trouble spots, which can lead to follow-up testing such as breast biopsies that are invasive and raise cancer fears for many patients. But research has found that very often these results turn out to be false alarms.

If 1,000 women with dense breasts get an ultrasound after a negative mammogram, the ultrasound will identify two to three cancers, studies show. But the extra imaging will also identify up to 117 potential problems that lead to recall visits and tests but are ultimately determined to be false positives.

“On the one hand, we want to do everything we can to improve detection,” said Dr. Sharon Mass, an ob.gyn. in Morristown, N.J., and the former chair of the American College of Obstetricians and Gynecologists’ New Jersey section. “But on the other hand, there are lots of costs and emotional distress” associated with false-positive results.

The professional group doesn’t recommend supplemental screening for women with dense breasts who don’t have any additional risk factors for cancer.

Many other professional groups take a similar position.

“We recommend having a conversation with a health care provider, and for patients to understand whether their breasts are dense,” Dr. Mass said. “But we do not recommend everyone get tested.”

KHN (Kaiser Health News) is a national newsroom that produces in-depth journalism about health issues. Together with Policy Analysis and Polling, KHN is one of the three major operating programs at KFF (Kaiser Family Foundation). KFF is an endowed nonprofit organization providing information on health issues to the nation.

When Katie Couric shared the news of her breast cancer diagnosis, the former co-host of NBC’s “Today” show said she considered this new health challenge to be a teachable moment to encourage people to get needed cancer screenings.

“Please get your annual mammogram,” she wrote on her website in September. “But just as importantly, please find out if you need additional screening.”

In the essay, Couric, 65, explained that because she tends to have dense breast tissue, she gets an ultrasound test in addition to a mammogram when screening for breast cancer. A breast ultrasound, sometimes called a sonogram, uses sound waves to take images of the breast tissue. It can sometimes identify malignancies that are hard to spot on a mammogram in women whose breasts are dense – that is, having a high proportion of fibrous tissue and glands vs. fatty tissue.

Ms. Couric, who famously underwent a colonoscopy on live television after her first husband died of colon cancer and who lost her sister to pancreatic cancer, has long pushed for cancer screening and better detection options.

Breast cancer experts applauded Ms. Couric for drawing attention to breast density as a risk factor for cancer. But some were less comfortable with her advocacy for supplemental screening.

“We don’t have evidence that auxiliary screening reduces breast cancer mortality or improves quality of life,” said Dr. Carol Mangione, a professor of medicine and public health at the University of California, Los Angeles, who chairs the U.S. Preventive Services Task Force, a group of medical experts who make recommendations for preventive services after weighing their benefits and harms.

Ms. Couric’s office did not respond to requests for comment.

In addition to an annual mammogram, some women with dense breasts get a breast ultrasound or MRI to help identify cancerous cells missed by the mammogram. Dense fibrous tissue appears white on a mammogram and makes it harder to see cancers, which also appear white. Fatty breast tissue, which appears dark on the mammogram, doesn’t obscure breast malignancies.

As digital breast tomosynthesis, or 3-D mammography, has become more widely available, a growing number of women are getting that screening test rather than the standard 2-D mammography. The 3-D mammography has been found to reduce the number of false-positive results and identify more cancers in some women with dense breasts, though the impact on mortality is unknown.

The task force gives an “I” rating to supplemental screening for women with dense breasts whose mammogram results don’t indicate a problem. That means the current evidence is “insufficient” to assess whether the benefits outweigh the harms of the extra screening. (The task force is updating its recommendation for breast cancer screening, including supplemental screening for women with dense breasts.)

One key harm that researchers are concerned about, besides the possible extra cost, is the chance of a false-positive result. Supplemental imaging in women who aren’t at high risk for breast cancer may identify potential trouble spots, which can lead to follow-up testing such as breast biopsies that are invasive and raise cancer fears for many patients. But research has found that very often these results turn out to be false alarms.

If 1,000 women with dense breasts get an ultrasound after a negative mammogram, the ultrasound will identify two to three cancers, studies show. But the extra imaging will also identify up to 117 potential problems that lead to recall visits and tests but are ultimately determined to be false positives.

“On the one hand, we want to do everything we can to improve detection,” said Dr. Sharon Mass, an ob.gyn. in Morristown, N.J., and the former chair of the American College of Obstetricians and Gynecologists’ New Jersey section. “But on the other hand, there are lots of costs and emotional distress” associated with false-positive results.

The professional group doesn’t recommend supplemental screening for women with dense breasts who don’t have any additional risk factors for cancer.

Many other professional groups take a similar position.

“We recommend having a conversation with a health care provider, and for patients to understand whether their breasts are dense,” Dr. Mass said. “But we do not recommend everyone get tested.”

KHN (Kaiser Health News) is a national newsroom that produces in-depth journalism about health issues. Together with Policy Analysis and Polling, KHN is one of the three major operating programs at KFF (Kaiser Family Foundation). KFF is an endowed nonprofit organization providing information on health issues to the nation.