Racial/ethnic and sex disparities in mortality among US cancer survivors.

backgrondCancer survivors in the United States face significant disparities in mortality influenced by race and sex. Despite advances in cancer treatment, the disparities of social determinants, behavioral health, and metabolic risk factors remain underexplored.

methodsAnalysis was based on the data from the National Health and Nutrition Examination Survey (NHANES) linked to the National Death Index and the follow-up data up to December 31, 2019. Survey-weighted multiple Cox regression was employed to assess the relationships of multiple risk factors and all-cause mortality. Analyses were informed by a conceptual causal framework (Directed Acyclic Graph). We performed an explanatory decomposition analysis to quantify the collective explanatory role of social determinants of health (SDoH) in the observed racial disparity.

resultsDuring median follow-up of 8.5 years, 2269 cancer survivors out of 6028 participants experienced all-cause mortality. In weighted analyses, we observed Black survivors had highest mortality rates (32.4%), followed by White (26.8%). Before covariables adjustment, Black had a higher all-cause mortality (HR 1.40, 95% CI 1.24-1.59) compared to the Whites. After adjustment of all covariables, there was no significant difference in mortality. Female cancer survivors had lower mortality rate (21.7%) and lower hazard ratio (HR 0.72, 95% CI 0.63-0.81). The analysis identified independent risk factors for increased mortality, including unemployment, lower family income, lack of private health insurance, current smoking, poor diet, physical inactivity, suboptimal sleep, hypertension, and diabetes. Central obesity was associated with lower mortality (HR 0.74, 95% CI 0.64-0.86), a finding that requires cautious interpretation due to potential reverse causation and confounding. Exploratory decomposition analysis suggested SDoH collectively explained a substantial portion of the unadjusted Black-White mortality difference.

conclusionIn this mixed population of cancer survivors, a higher burden of social and behavioral risk factors was associated with increased mortality. The findings underscore the critical need to integrate SDoH assessment and mitigation into long-term survivorship care to address social determinants and health behaviors to promote equity in survivorship outcomes. Future research with detailed clinical data is needed to disentangle the effects of cancer type and stage from post-diagnostic factors.