Cardiovascular risk in long-term survivors of breast, prostate, colon, and rectal cancer

BACKGROUND: Cardiovascular disease (CVD) is the leading cause of noncancer mortality in long-term cancer survivors. Population-level assessment of cancer-related exposures is limited with respect to long-term cardiovascular risk in older survivors who have additional aging-related risks. METHODS: This was a Surveillance, Epidemiology, and End Results-Medicare retrospective cohort study of long-term (5-year) survivors of breast, prostate, colon, and rectal cancers who were aged 66 years and older, diagnosed from 2003 to 2012, and received definitive treatment. The primary endpoint was late CVD, defined as myocardial infarction, stroke, congestive heart failure, or cardiomyopathy on an inpatient administrative claim or as Surveillance, Epidemiology, and End Results cause of death occurring 5-15 years postdiagnosis. Restricted mean survival time regression was used to assess predictors of shorter average time without CVD and develop a prediction rule for risk stratification. Survivors were assigned a risk score and stratified into tertiles. RESULTS: Included were 95 100 survivors with a mean age of 74 (6) years at diagnosis. Late CVD occurred in 23.2% of survivors. Older age, comorbidities, and prior CVD were associated with a shorter time without CVD. In contrast, cancer-related factors were not associated, except for stage III breast cancer, and radiation plus androgen deprivation therapy for prostate cancer. Across all cohorts, the high-risk strata had a three- to fourfold higher risk of CVD compared with the low-risk strata. CONCLUSIONS: In this cohort of older, long-term cancer survivors, cancer-related exposures were not independently associated with onset of CVD 5-15 years after diagnosis but may still contribute to latent cardiovascular risk. Given the limited impact of cancer-specific factors, cancer-agnostic risk prediction may be adequate to predict individual cardiovascular risk.