Abstract C059: Sociodemographic patterns of racial disparities in cardiovascular disease mortality after breast cancer diagnosis by estrogen receptor status

Abstract

Cardiovascular disease (CVD) is the leading non-cancer cause of death among breast cancer (BC) survivors. Although racial differences in CVD mortality after BC diagnosis are well documented, whether these patterns vary across sociodemographic factors and estrogen receptor (ER) status has not been well characterized. We examined differences in CVD mortality between non-Hispanic Black (NHB) and non-Hispanic White (NHW) BC survivors across sociodemographic groups by ER status. We identified NHB and NHW women diagnosed with a first primary localized or regional breast cancer in the SEER program during 2006–2020, with follow-up through 2021. We estimated the 10-year cumulative CVD mortality, treating BC death and death from other causes as competing events. Estimates were stratified by race and ER status (+/−) and across age at diagnosis, marital status, and census tract–level rurality and socioeconomic status (SES). Among 474,002 women, 16,044 CVD deaths occurred during follow-up (median follow-up time=5.8 years). Overall, the 10-year cumulative CVD mortality was higher among NHB than NHW women with ER+ disease (5.72% [95% CI, 5.41%–6.03%] vs. 5.04% [95% CI, 4.94%–5.14%]) but lower among those with ER− disease (3.74% [95% CI, 3.36%–4.12%] vs. 4.00% [95% CI, 3.80%–4.20%]). Among women with ER+ disease, NHB women consistently experienced higher cumulative CVD mortality across all age groups, with the largest absolute difference among women aged 50–64 years (3.46% [95% CI, 3.07%–3.85%] vs. 1.32% [95% CI, 1.23%–1.40%]). Similar patterns were observed among married women and women living in rural areas, whereas racial differences were less pronounced among unmarried women and urban residents. In contrast, among women with ER− disease, the higher cumulative CVD mortality among NHB than NHW women were largely limited to those diagnosed before age 65. Unmarried NHW women with ER− disease had a higher cumulative CVD mortality than their NHB counterparts (7.97% [95% CI, 7.42%–8.51%] vs. 6.02% [95% CI, 5.12%–6.92%]). Across both ER subtypes, NHW women generally had a higher cumulative CVD mortality than NHB women within middle SES groups, whereas racial differences were less pronounced in the lowest and highest SES groups. NHB women experienced a higher burden of CVD mortality than NHW women diagnosed with ER+ breast cancer across nearly all sociodemographic groups. In contrast, patterns among women with ER− disease were more heterogeneous and, in some subgroups, reversed. These findings suggest that racial differences in CVD outcomes after breast cancer are also shaped by the interplay of tumor subtype and social factors. The persistent racial disparity among women with ER+ disease, a highly treatable disease with favorable survival, warrants further investigation of potentially modifiable contributors, including baseline cardiovascular risk, treatment-related exposures, access to preventive care, and survivorship management. Xinyi Feng, Lindsay J. Collin, Maret L. Maliniak, Nida Waheed, Shipra Gandhi, Rohini K. Bhatia, Lauren E. McCullough, Jacqueline B. Vo. Sociodemographic patterns of racial disparities in cardiovascular disease mortality after breast cancer diagnosis by estrogen receptor status [abstract]. In: Proceedings of the 19th AACR Conference on the Science of Cancer Health Disparities; 2026 Oct 18-21; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2026;35(10 Suppl):Abstract nr C059.