Researchers at the Barbara Ann Karmanos Cancer Institute conducted a study to identify predictors of nonadherence to breast cancer screening guidelines among women at high and average risk for breast cancer in the U.S. Their analysis, “Predictors of nonadherence to breast cancer screening guidelines in a United States urban comprehensive cancer center,” was published in Cancer Medicine in May 2023.
The researchers evaluated screening patterns among patients at the Karmanos breast cancer screening clinic in Detroit against national breast cancer screening guidelines. The screening clinic at Karmanos is unique because it is in a dense, urban area with a majority Black population.
Most breast cancers in the U.S. are identified through abnormal screening tests. Routine screening through mammograms and other imaging modalities, such as MRI, significantly reduces breast cancer mortality and enables earlier initiation of treatment. Supplemental screening with MRI increases cancer detection rates by up to 56% in high-risk women. Though there is variation across national guidelines, this study focused on adherence to the American Cancer Society (ACS) guidelines. The ACS guidelines recommend biannual mammograms for women at average risk for breast cancer and additional supplemental imaging with MRI between screening mammograms for women at high risk.
The study showed that 6.9% of women at average or high risk for breast cancer had screening that was inconsistent with guidelines. Just over 97% of high-risk women in the sample were incongruently screened, meaning they did not receive supplementary screening when suggested.
The researchers concluded that the screening patterns among average and high-risk women may be attributed to the lack of standard guidelines instead of different recommendations from each organization, such as the ACS, U.S. Preventive Services Task Force, American College of Radiology, and more. They also believe that cost may be a barrier to receiving supplemental imaging. Currently, the Affordable Care Act does not cover screening breast MRIs for women at high risk for breast cancer. MRIs are 5-10 times more expensive than screening mammography.
This study also found that average-risk women with dense breasts had an increased likelihood of supplementary screening compared to those without dense breasts, which is also against recommendations. Breast density is a well-known risk factor for breast cancer; however, there are no standardized guidelines regarding breast cancer screening for women with dense breasts. The co-authors believe this could be due to the mandated breast density notification law enacted in Michigan before the study began. The state law requires notification of breast density status to women with dense breasts. Though the research team cannot conclude this from the study, evidence suggests clinicians may be inclined to recommend supplementary imaging regardless of recommendations since breast density is a known risk factor.
Co-authors of this study include Alexandra Wehbe, M.D., MPH; Madeleine Gonte, M.D., MPH; Suzanne C. O'Neill, Ph.D., Alit Amit-Yousif, M.D.; Kristen Purrington, Ph.D.; Mark Manning, Ph.D.; and Michael S. Simon, M.D., MPH.
Read the study here.