Racial and Ethnic Disparities in Risk of Cardiovascular Disease in Women Treated for Breast Cancer

Racial and ethnic disparities exist in cardiovascular disease (CVD) burden in the general population; yet surprisingly few studies have examined such disparities in breast cancer patients, who are at higher risk due to cardiotoxic therapy. To investigate incidence of CVD and cardiometabolic risk factors across Asian, non-Hispanic Black (NHB), Hispanic, and non-Hispanic White (NHW) women with a history of breast cancer. In 4,071 women with breast cancer from a prospective cohort, the incidence of cardiometabolic risk factors and CVD occurring after breast cancer diagnosis were analyzed with self-identified race and ethnicity (SIRE) and global genetic ancestry. Racial and ethnic differences existed in the prevalence of cardiometabolic risk factors and CVD before breast cancer diagnosis, which continued to manifest in incident cases after cancer treatment. Asian, NHB, and Hispanic women were all at higher risk of diabetes than NHW women. Nonetheless, only NHB women had higher risk of CVD events, and Hispanic women were at lower risk. The apparent lower risk of CVD in Asian women largely disappeared after adjustment for covariates. Similar differences across SIRE groups were found in the cardiotoxic chemotherapy subgroup and the subgroup without chemotherapy, except for any CVD and VTE showing modifying effects of cardiotoxic chemotherapy. Analyses of genetic ancestry revealed similar results to SIRE. Our study reveals racial and ethnic disparities in cardiometabolic risk factors and CVD events before and after breast cancer diagnosis. Clinical and research attention is warranted to bridge the population-level gaps in CVD morbidity and mortality. Statement of Significance: Our study provides strong evidence for racial and ethnic disparities in cardiovascular disease before and after breast cancer diagnosis. Clinical and research attention is warranted to bridge these population-level gaps.