Joint association of cancer and cardiovascular disease with all-cause mortality

Cancer and cardiovascular disease (CVD) are the two leading causes of death in the United States. Whether their coexistence confers excess mortality risk remains insufficiently characterized. This study looks to examine the cross-sectional association between cancer history and prevalent CVD and evaluate their joint association with all-cause mortality.

We analyzed 8,525 participants from the Third National Health and Nutrition Examination Survey. Cancer history was self-reported and categorized as skin or non-skin cancer. CVD was defined by self-reported clinical disease or major electrocardiographic abnormalities. Cross-sectional associations between cancer and prevalent CVD were evaluated using multivariable logistic regression. Longitudinal associations with all-cause mortality were examined using Cox proportional hazards models with joint exposure categories, adjusting for sociodemographic and cardiometabolic covariates. Interaction testing assessed effect modification.

Cancer history was not independently associated with prevalent CVD after multivariable adjustment (skin cancer OR 1.05, 95% CI 0.84-1.30; non-skin cancer OR 1.21, 95% CI 0.97-1.50). Both CVD (adjusted HR 1.45, 95% CI 1.36-1.56) and cancer (skin cancer HR 1.15, 95% CI 1.02-1.29; non-skin cancer HR 1.54, 95% CI 1.37-1.72) were independently associated with higher all-cause mortality. The highest risk was observed among individuals with both CVD and non-skin cancer (adjusted HR 2.42, 95% CI 2.04-2.88). The CVD-cancer interaction was not statistically significant (p=0.596).

The coexistence of cancer and CVD identified a population at markedly elevated mortality risk, consistent with an additive rather than synergistic joint association, highlighting the need for integrated cardio-oncologic risk stratification.