Abstract Purpose: We examined the associations between healthcare system distrust (HCSD), sexual orientation, and race to determine how they impacted concordance with mammography screening recommendations among people at objectively high risk for breast cancer (BC). We hypothesized that sexual minority women and Black women would report greater levels of HCSD and be less likely to be concordant with mammography screening guidelines. We further hypothesized that HCSD mediated the relationship between sexual orientation and mammography concordance. Methods: We used survey data from the high-risk subsample of The Daughter Sister Mother Project survey. Participants were 18-75, non-Hispanic white or non-Hispanic Black/African American, identified as “female”, had no prior history of cancer, and had ≥20% lifetime risk of BC according to ≥1 risk prediction model (Gail, Claus, IBIS). Mammography concordance was defined as having reported receipt of a mammogram within the last year if recommended according to National Comprehensive Cancer Network guidelines for women at high risk. We used two-sample t-tests to compare mean HCSD scores (measured with the Revised HCSD Scale, 5-25 with higher scores indicating greater distrust) by sexual orientation and race. We used linear and logistic regression to estimate bi- and multivariable associations with HCSD and mammography concordance separately. Finally, we conducted a traditional mediation analysis to determine whether HCSD mediated the association between sexual orientation and mammography concordance using Baron and Kenny’s four-step approach. Results: There were 402 participants included in this analysis (9.2% sexual minority, 90.8% straight; 31.1% Black, 68.9% white). Sexual minority participants scored on average 1.90 points higher on the HCSD scale (p=0.004) and had 0.64 times the odds of mammography concordance (p=0.233) compared to heterosexuals, adjusting for age and race. Black participants scored on average 2.81 points higher on the HCSD scale (p0.001) and had 0.42 times the odds of mammography concordance (p0.001) compared to white participants, adjusting for sexual orientation and age. HCSD did not meet the criteria for a mediator, though we were unable to rule out mediation due to sample size restrictions. Conclusion: Sexual minority participants and Black participants had greater HCSD, and lower odds of mammography concordance compared to heterosexual and white participants, separately. Further research is needed to explore the role of HCSD in shaping the experiences of high-risk women and their access to BC risk management options. Importantly, future research should examine the intersectional experiences of Black sexual minority women with heightened BC risk—which we were unable to explore due to sample size—with the end goal of designing systems and policies that mitigate the harmful effects of homophobia and racism within the healthcare system. Citation Format: Kaleb M. Masterson, Alison H. Norris, Rachel Meadows, Tasleem J. Padamsee. Mammography concordance among sexual minority women at elevated risk of breast/chest cancer: Examining the roles of race and healthcare system distrust abstract. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr B070.
Masterson et al. (Thu,) studied this question.