Risk of Cardiovascular Diseases Among Older Breast Cancer Survivors in the United States: A Matched Cohort Study.

BACKGROUND

It has been suggested that cardiovascular risks are increased in breast cancer survivors, but few studies have quantified the risks of a range of specific clinically important cardiovascular outcomes in detail.

PATIENTS AND METHODS

Women aged >65 years with incident breast cancer from 2004 to 2013 in the SEER-Medicare linked database were matched with 5 cancer-free female counterparts (5:1 ratio). Prevalence of specific cardiovascular outcomes at baseline was measured, then Cox regression was used to calculate hazard ratios (HRs) and 95% confidence intervals for the risk of individual cardiovascular outcomes during follow-up. Modification of the effect was investigated by time since diagnosis, race/ethnicity, prior cardiovascular disease (CVD), and age.

RESULTS

In all, 91,473 women with breast cancer and 454,197 without breast cancer were included. Women with breast cancer had lower baseline prevalence of all CVDs. Compared with cancer-free controls, breast cancer survivors had substantially increased risks of deep vein thrombosis (adjusted HR, 1.67; 95% CI, 1.62-1.73; 386,484 person-years of follow-up) and pericarditis (HR, 1.43; 95% CI, 1.38-1.49; 390,776 person-years of follow-up); evidence of smaller increased risks of sudden cardiac arrest, arrhythmia, heart failure, and valvular heart disease (adjusted HRs ranging from 1.05-1.09, lower CI limits all ≥1); and evidence of lower risk of incident angina, myocardial infarction, revascularization, peripheral vascular disease, and stroke (adjusted HRs ranging from 0.89-0.98, upper CI limits all ≤1). Increased risks of arrhythmia, heart failure, pericarditis, and deep vein thrombosis persisted >5 years after cancer diagnosis.

CONCLUSIONS

Women with a history of breast cancer were at increased risk of several CVDs, persisting into survivorship. Monitoring and managing cardiovascular risk throughout the long-term follow-up of women diagnosed with breast cancer should be a priority.