Introduction and Purpose: Women with dense breasts have increased risk both for developing breast cancer and false-negative mammograms. Supplemental screening with breast MRI has been shown to shown to significantly increase cancer detection among women with dense breasts. In May 2023, Pennsylvania (PA) mandated insurance coverage of one supplemental screening study (breast MRI or ultrasound ) annually for women with dense breasts. Prior research suggests that Black women have lower breast density on average than white women based on subjective grading from the American College of Radiology Breast Imaging and Reporting Data System (BI-RADS), partially due to larger average breast size and higher body mass index (BMI) than white women. The purpose of this study was to estimate the potential impact of this supplemental screening law on different patient populations in a large health system. Methods: Women without prior breast cancer or known BRCA1/2 mutations who underwent mammographic screening at a large PA health system from April 2015-December 2017and completed a risk factor questionnaire were included (N=83,579). Under PA law, women must have either heterogeneously dense breasts plus >20% lifetime risk of breast cancer or extremely dense breasts to be eligible for insurance coverage for supplemental screening, both of which involve subjectively graded breast measurements. Breast cancer risk for each patient was estimated using the Gail model. The cancer detection rate (CDR) for mammographic screening was calculated as the number of cancers diagnosed within one year of a positive mammographic screen; the interval cancer rate was calculated as the number of cancers diagnosed within one year of a non-actionable screening mammogram per 1000 women. Logistic regression was used to calculate the odds of eligibility adjusted for age and BMI. Results: Black women were less likely to have extremely or heterogeneously dense breasts than white women (23.7% vs. 45.0%, p<0.001). Under PA law, 2.5% of Black women and 9.9% of white women would qualify for insurance coverage for supplemental screening (p<0.001). Only 0.2% of Black women and 2.3% of white women had heterogeneously dense breasts and >20% lifetime risk. Black women were more likely to have triple-negative breast cancer (TNBC) than white women (p<0.001). After adjusting for age and BMI, Black women remained 54% less likely to be eligible for supplemental screening than white women (OR=0.46, 95% 0.42-0.51, p<0.001).Conclusions: Black women are less likely to qualify for insurance coverage for supplemental breast cancer screening than white women under PA law. Given that Black women have lower prevalence of subjectively graded dense breasts and higher prevalence of TNBC, the new supplemental screening law is unlikely to meaningfully reduce racial disparities in breast cancer mortality. Methods to better assess breast cancer risk among Black women, particularly the risk of TNBC, are urgently needed to identify Black women that may benefit from supplemental screening.

Citation Format: Mattia A. Mahmoud, Sarah Ehsan, Oluwadamilola M. Fayanju, Susan M. Domchek, Katherine L. Nathanson, Despina Kontos, Emily F. Conant, Anne Marie McCarthy. Racial disparities in insurance coverage for supplemental breast cancer screening [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr C118.