Biennial Mammography Over Annual Mammography? USPSTF Issues Updated Breast Cancer Screening Recommendations

The United States Preventive Services Task Force (USPSTF) has released final updates to the organization’s breast cancer screening recommendations. The USPSTF cites insufficient evidence for the use of supplemental MRI or ultrasound in women with dense breasts, and screening mammography in women 75 and older. The organization also maintained that biennial mammography screening offers a greater benefit/risk ratio in comparison to annual screening for women aged 40 to 74.

The recommendations, published earlier today in the Journal of the American Medical Association (JAMA), said there was no difference between annual and biennial mammography with respect to stage IIB and higher cancer detection based on a 2015 analysis of data from the Breast Cancer Surveillance Consortium (BCSC). Other research, cited by the USPSTF, from 2024 found that annual mammography screening would yield a 50 percent higher number of false-positive results in comparison to biennial mammography screening.

“Available evidence suggests that biennial screening has a more favorable trade-off of benefits vs harms than annual screening,” wrote Wanda K. Nicholson, M.D., MPH, MBA, the chair of the USPSTF, a professor of prevention and community health at the Milken Institute School of Public Health at George Washington University, and colleagues.

In updated breast cancer screening recommendations, the United States Preventive Services Task Force (USPSTF) says biennial mammography screening offers a greater benefit/risk ratio in comparison to annual screening for women aged 40 to 74. (Image courtesy of Adobe Stock.)

In an accompanying editorial, Wendie A. Berg, M.D., Ph.D., disputed some of the evidence the USPSTF cited in support of its recommendation of biennial mammography screening. For premenopausal women, the aforementioned BCSC data revealed that biennial mammography screening was associated with an increased risk of stage IIB or higher disease in comparison to annual mammography exams, according to Dr. Berg, a professor of radiology at the University of Pittsburgh School of Medicine.

While conceding a higher number of cumulative false positive results with annual mammography screening, Dr. Berg said the marginal rates for false positives and benign biopsies are lower with annual screening.

Citing data from the Cancer Intervention and Surveillance Modeling Network (CISNET), Dr. Berg pointed out that annual mammography screening led to a 35.2 percent decrease in breast cancer mortality reduction in contrast to a 28.4 percent reduction with biennial screening in women 40 to 74 years of age.

“Using USPSTF terminology, annual screening is just as “efficient” as biennial screening but produces greater overall reductions in late-stage disease and deaths due to breast cancer, and greater gains in years of life saved,” noted Dr. Berg.

Citing the DENSE randomized controlled trial, which compared the combination of digital mammography and MRI to digital mammography alone in patients 50 to 75 years of age with extremely dense breasts, the USPSTF authors acknowledged a lower interval cancer rate with supplemental MRI (2.2 cases per 1000 vs. 4.7 cases per 1000). However, the same study also noted a recall rate of 94.9 per 1000 screens and a false-positive rate of 79.8 per 1000 screens with the use of supplemental MRI, according to Nicholson and colleagues.

In their systematic review, the USPSTF authors also noted a lack of studies evaluating the impact of supplemental MRI upon mortality reduction or detection of breast cancer for multiple screening rounds.

Dr. Berg said the USPSTF recommendations “minimized” the evidence demonstrating that mammography screening alone is “inadequate” for women with dense breasts. Dr. Berg emphasized that women with extremely dense breasts have a four- to sixfold higher risk for breast cancer in comparison to women with fatty breasts.

Breast density notification language, required by the Food and Drug Administration (FDA) in mammography reporting as of September 10, 2024, will explain to patients that supplemental imaging may be necessary to detect breast cancer in some patients with dense breast tissue, points out Dr. Berg. She also noted that current recommendations from the American College of Radiology (ACR) advocate annual breast MRI exams, starting at the age of 40, in women with dense breasts who indicate a preference for supplemental imaging.

(Editor’s note: For related content, see “Do the New USPSTF Recommendations Go Far Enough on Mammography Screening?,” “Study Shows Benefits of Annual Mammography Exams from 40 to 79 Years of Age” and “European Society of Breast Imaging Issues Updated Breast Cancer Screening Recommendations.”)

In regard to determining the age for cessation of mammography screening, the USPSTF authors noted that a study based off Medicare claims data for 264,274 women found a 22 percent decrease in breast cancer mortality reduction with continued mammography screening between 70 and 74 years of age. However, the same study revealed no difference in absolute rates of breast cancer mortality with continued mammography screening for women between 75 and 84 years of age, according to Nicholson and colleagues.

Otherwise, the USPSTF authors noted that evidence evaluating the appropriate age for cessation of mammography screening was limited.

“The USPSTF did not identify any RCTs designed to test the comparative effectiveness of different ages to start or stop screening that reported morbidity, mortality, or quality-of-life outcomes,” added Nicholson and colleagues.

Citing the aforementioned CISNET data, Dr. Berg said researchers determined that annual mammography screening for women between 40 to 79 years of age achieved a 41.7 percent reduction in breast cancer mortality.