Breast · Jul 1, 2019

Bisphosphonate use and incident cardiovascular events among older breast cancer survivors

By Gegechkori N, Egorova N, Mhango G et al.

BACKGROUND: Cardiovascular disease (CVD) is a leading cause of mortality in early-stage breast cancer survivors. Recent studies suggest that bisphosphonates may decrease CVD risk in older patients. OBJECTIVE: This study sought to assess whether bisphosphonate use is associated with lower rates of incident CVD events among early-stage breast cancer survivors. METHODS: Longitudinal, population-based cohort study was conducted by using data from the Surveillance, Epidemiology and End Results registry linked to Medicare claims. We identified women >65 years with no history of CVD who were diagnosed with stage 0-III primary breast cancer between 2007 and 2010. Our primary outcome was a composite of incident angina pectoris, myocardial infarction, atrial fibrillation/flutter, heart failure, or stroke within 36 months of cancer diagnosis. Bisphosphonate use was defined as the presence of ≥1 pharmacy claim from 6 months prior to cancer diagnosis to the incident CVD event. We used propensity scores to create a matched group of breast cancer survivors without bisphosphonate exposure to compare rates of incident CVD events. RESULTS: A total of 2178 breast cancer survivors had ≥1 bisphosphonate prescription; the average length of bisphosphonate use was 15 months. Analyses of the matched data showed that 13.0% of bisphosphonate users and 23.4% of non-bisphosphonate users experienced an incident CVD event (p < 0.0001) after breast cancer diagnosis. Bisphosphonate use was significantly associated with fewer incident CVD events (hazard ratio: 0.51, 95% confidence interval: 0.44 to 0.59). CONCLUSIONS: Bisphosphonate use is associated with lower incidence of CVD events among older early-stage breast cancer survivors. Future studies should prospectively evaluate whether bisphosphonate use can decrease CVD incidence.

doi.org/10.1016/j.breast.2019.06.006PubMed 31310951Populations