(HealthDay News) — The U.S. Preventive Services Task Force (USPSTF) recommends breast cancer screening for women aged 40 to 75 years, but evidence is insufficient for older women and for supplemental screening for women with dense breasts. These recommendations form the basis of a final recommendation statement published online April 30 in the Journal of the American Medical Association.
Jillian T. Henderson, Ph.D., M.P.H., from the Kaiser Permanente Evidence-based Practice Center in Portland, Oregon, and colleagues reviewed studies comparing different breast cancer screening strategies. Data were included from seven randomized trials and 13 nonrandomized studies. The researchers observed no mortality difference for screening beyond age 74 years based on a nonrandomized trial emulation study. In a nonrandomized study, advanced cancer detection did not differ following annual or biennial screening intervals. Reduced interval cancer risk but additional false-positive recalls and biopsy results were seen in a randomized clinical trial of individuals with dense breasts undergoing supplemental screening with magnetic resonance imaging. In a modeling study, Amy Trentham-Dietz, Ph.D., from the University of Wisconsin-Madison, and colleagues found that biennial digital breast tomosynthesis starting at age 40 to 74 years was associated with a 30.0 percent reduction in breast cancer mortality. Similar benefits were seen with digital mammography screening, but more false-positive recalls occurred.
Based on these findings, the USPSTF recommends biennial screening mammography for women aged 40 to 74 years (B recommendation), with moderate net benefit. For women aged 75 years or older, the current evidence is insufficient for assessing the balance of benefits and harms of screening mammography (I statement). For women with dense breasts, the current evidence is insufficient for assessing the balance of benefits and harms of supplemental screening with breast ultrasonography or magnetic resonance imaging (I statement).
“We’re asking the research community to prioritize studies that can show us how best to screen for breast cancer in women with dense breasts,” task force chair Wanda Nicholson, M.D., M.P.H., said in a statement.
Several authors disclosed ties to the pharmaceutical and diagnostics industries.
Breast cancer screenings and Black women
Dense breasts, characterized by a higher proportion of glandular and connective tissues compared to fatty tissue, pose a unique challenge for breast cancer screening, particularly for Black women. While dense tissue can elevate breast cancer risk, it also appears white on mammograms, the same way tumors do. This overlap can obscure potential cancers, making them harder to detect in mammograms – the mainstay of early breast cancer screening.
Research from the American Association for Cancer Research highlights that dense breasts not only reduce the sensitivity of mammograms but may also be linked to a higher risk of aggressive breast cancers. This is especially concerning for Black women who are already diagnosed with breast cancer at later stages and have a higher mortality rate from the disease compared to white women.
Dense breasts and Black women
Several factors contribute to this disparity. Dense breasts are more prevalent in younger women and Black women are more likely to have denser breast tissue compared to white women. Additionally, factors like higher body mass index (BMI) can influence breast density, and Black women tend to have a higher average BMI than white women.
The recent FDA regulation requiring mammogram reports to disclose breast density empowers women with this crucial information. However, for Black women with dense breasts, this knowledge can be unsettling, highlighting the limitations of standard screening.
There are discussions about incorporating additional screening modalities for women with dense breasts. Ultrasound and breast MRI can provide a clearer picture, but these tests are often more expensive and less accessible. Ongoing research is crucial for developing more effective and equitable screening strategies for all women, particularly Black women facing a higher risk and poorer outcomes.