Between-Race Differences in Supplemental Breast Cancer Screening Before and After Breast Density Notification Law.

Guidelines recommend supplemental breast cancer screening for women at increased breast cancer risk; however, the passage of breast density notification laws may lead to supplemental screening that is incongruent with women's risk. We examined supplemental screening (ie, MRI, ultrasound, or tomosynthesis within 6 months of screening mammogram) among a sample of 2,764 African American (AA) and 691 European American (EA) women with negative or benign screening mammograms for whom we had data from both before and after implementation of breast density notification laws in the state of Michigan. Results indicated a 5-fold increase (from 0.14% to 0.7% of women) in supplemental screening among screen-negative women after passage of the law, driven in large part by an increase in supplemental screening among AA women. Breast density was more predictive of supplemental screening and had a marginally greater explanatory role in between-race differences in supplemental screening after passage of the law. Subgroup analyses (n = 250) indicated that whereas 5-year breast cancer risk was positively associated with supplemental screening before the law and negatively associated after the law for EA women, 5-year risk was not associated with supplemental screening either before or after passage of the law for AA women. Our findings suggest that whereas passage of the breast density notification laws may have motivated supplemental screening among AA women in particular, it lessened the consideration of breast cancer risk in supplemental screening decision making.