Objective:Breast cancer patients have improved overall survival and life expectancy. Cardiovascular disease (CVD) is the leading cause of non-cancer deaths in this population. Assessing health-related quality of life (HRQoL) among breast cancer patients with comorbid-CVD is increasingly important. We aimed to evaluate the association of the comorbid-CVD and adjuvant endocrine therapy with HRQoL among older women with early-stage breast cancer in the U.S.

Methods:We conducted a retrospective cohort study using the 2006-2017 Surveillance, Epidemiology, and End Results-Medicare Health Outcomes Survey data. We identified females who were over 65 and diagnosed with stage I-III hormone receptor-positive breast cancer. HRQoL was measured by the physical and mental component summary (PCS & MCS) in the 12-item Veteran RAND health survey. CVD was defined as having a history of acute myocardial infarction (AMI), congestive heart failure (CHF), angina, stroke, or other heart-related conditions. Adjuvant endocrine therapy type was classified into tamoxifen and aromatase inhibitors. Multivariate linear regression models were performed while controlling for covariates.

Results:Among 3,904 women, having a history of CHF [β=-1.97, p=0.025], stroke [β=-3.00, p<0.010], or other heart-related condition [β=-1.10, p=0.046] was significantly associated with lower PCS. No significant differences in PCS were found between women with a history of AMI or angina and those without these conditions. Having a history of CHF [β=-1.72, p=0.033] or stroke [β=-1.48, p=0.038] was significantly associated with lower MCS. A history of angina, AMI, or other heart conditions was not associated with significant differences in MCS. No significant differences in PCS and MCS were observed between tamoxifen and aromatase inhibitors.

Conclusion:Among older women with early-stage breast cancer, a history of CHF and stroke were strong predictors for decreased HRQoL. This finding suggests the importance of managing comorbid-CVD for better HRQoL among older women with early-stage breast cancer.