May 1, 2024 -- Women who are considered to be at average risk for breast cancer should have mammograms every other year starting at age 40 years until they turn 74, according to the latest recommendations from the U.S. Preventive Services Task Force.
In 2016, the task force recommended biennial mammograms for women starting 10 years later, at age 50, while stressing a need for clinicians and patients to weigh the risks and benefits of screening for those in their 40s. Alongside the recommendations published in the Journal of the American Medical Association werethree separate editorials — a reflection of the controversy that these breast cancer screening recommendations often generate.
In one editorial, Lydia E. Pace, MD, MPH, and Nancy L. Keating, MD, MPH, wrote that although screening earlier will prevent more deaths from breast cancer, it will also lead to more false positive findings and increase rates of overdiagnosis.
Pace and Keating explained that the modeling study commissioned by the USPSTF estimated that screening every 2 years starting at age 40 would avoid an additional 1.3 breast cancer deaths compared with screening at age 50. Among Black women, screening every 2 years starting at age 40 would avoid an extra 1.8 breast cancer deaths for every 1,000 people screened.
However, the model also found that screening every 2 years starting at age 40 would lead to more false positive tests — a rate of about 8.5% vs 7.8% for those starting at age 50.
The shift to a general recommendation to start at age 40 is based on a broad review of available data on mammography, including modeling from Cancer Intervention and Surveillance Modeling Network (CISNET).
In its updated recommendations, the the task force also made an urgent call to address reasons why Black women are more likely to die from breast cancer than white women and pressed for more research to address lingering questions about how best to screen for cancer in dense breasts, which about 40% of women have. The recommendations highlighted evidence gaps on the benefits and harms of continuing mammography after age 75 years as well.
"Given mammography screening's modest benefits, we feel that all women—and particularly those aged 40 to 49 years—should be counseled about the benefits and harms of mammography and supported in deciding whether the balance of benefits to harms fits with their priorities and values," wrote Pace and Keating, who both have specialties in internal medicine.
In a second editorial, Joann G. Elmore, MD, MPH, of UCLA, and Christoph I. Lee, MD, of the University of Washington wrote that the revised recommendations "shed light on two major issues that demand greater attention: addressing health inequities related to breast cancer outcomes and ensuring benefits for all women amid rapid screening technological advancements."
The UPSTSF's decision to recommend an earlier start age for routine mammograms was partly intended to begin to address the fact that Black women are about 40% more likely to die from breast cancer than white women.
"Despite greater absolute benefits of screening for Black women, the modeling study and systematic review underscore that mammography's benefits (i.e., breast cancer deaths averted) are modest for both Black women and the general population," Elmore and Lee wrote.
The authors also cautioned against adopting artificial intelligence support tools too rapidly, criticizing the USPSTF for overlooking this "pressing issue."
"While AI algorithms show promise for enhancing cancer detection, their impact on patient outcomes and the balance between benefit and harms remain uncertain," Elmore and Lee wrote.
In a third JAMA editorial, Wendie A. Berg, MD, PhD, a radiologist at the University of Pittsburgh, argued that though the updated recommendations are "an important step forward," they don't go far enough.
Berg, for instance, noted her surprise "to see the USPSTF recommendation only for biennial, rather than annual, screening among women aged 40 to 74 years."
Compared with no screening, annual screening would reduce rates of breast cancer mortality (35.2%) more than biennial (28.4%) screening does among women aged 40-74 years, according to the modeling that informed the USPSTF's decision.
Plus, Berg noted, regular risk assessments should begin at age 25 years "to identify women at high risk who should start annual MRI screenings."
The American College of Radiology offered similar views in a statement, saying the recommendations "do not go far enough to save more women's lives." It urged a more aggressive screening schedule, which starts at age 40 but occurs annually vs. biennially and continues past age 74. Like Berg, the group advocated for breast cancer risk assessments to begin at age 25 years.
The American Cancer Society also recommended annual mammograms, starting as early as age 40 in average-risk women, with high-risk women receiving a breast MRI and a mammogram every year starting at age 30.