Age and Racial Disparities in the Utilization of Anticancer, Antihypertension, and Anti-diabetes Therapies, and in Mortality in a Large Population-Based Cohort of Older Women with Breast Cancer

Objective This study examined the receipt of therapies for cancer, hypertension, and diabetes in association with age and racial disparities in mortality among women with breast cancer. Methods This study identified 92,829 women diagnosed with breast cancer at age ≥ 65 years in 2007–2015 with follow-up to 2016 from the Surveillance, Epidemiology, and End Results (SEER)-Medicare linked database. Results There were substantial age and racial disparities in the prevalence of hypertension and diabetes, which was higher in women ≥ 75 (86.3% and 32.0%) than younger women 65–74 (72.8% and 29.3%), and the highest in Black women (91.1% and 49.1%), followed by Asian women (80.2% and 40.5%), and White women (77.6 and 27.8%). Black women were significantly less likely to receive chemotherapy (odds ratio: 0.70, 95% CI: 0.64–0.75), radiation therapy (0.87, 0.83–0.92), and hormone therapy (0.80, 0.76–0.85), but significantly more likely to receive antihypertensive (1.26, 1.19–1.33) and antidiabetic (1.19, 1.10–1.28) drugs than White women, after adjusting for sociodemographic and tumor factors. As compared to White women, Black women had a significantly higher risk of all-cause mortality (1.46, 1.41–1.52), but it became insignificant after adjusting for treatment factors (1.01, 0.97–1.06), whereas the adjusted risk of breast cancer-specific mortality remained significantly higher (1.08, 1.01–1.15) in Black women; Asian and other ethnic women had a significantly lower risk of all-cause and breast cancer-specific mortality. Conclusions There were substantial age and racial disparities in the prevalence of hypertension and diabetes and in the receipt of medications. Black women did not have a significantly higher risk of all-cause mortality but had a significantly higher risk of breast cancer-specific mortality as compared to White women.