Difference in excess late mortality between early-onset and late-onset cancer survivors: a nationwide cross-sectional...

While excess late mortality in early-onset cancer survivors has been documented, no prior study has directly compared these outcomes between early-onset and late-onset survivors.

This study utilized data collected by the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018. Participants were adults aged 20 years or older with a history of cancer who survived at least 5 years post-diagnosis. Participants were categorized into early-onset cancer survivors (diagnosed between ages 20 and 49) and late-onset cancer survivors (diagnosed at age 50 or older). Standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) were calculated using age-specific, sex-specific, and calendar year-specific mortality rates from the general population as reference. Incidence rate ratios (IRRs) were estimated using multivariate Poisson regression.

A total of 3082 cancer survivors were included, comprising 1199 (48.3%) early-onset cancer survivors and 1883 (51.7%) late-onset cancer survivors. The overall SMRs were 2.07 (95% CI: 1.76-2.44) for early-onset cancer survivors and 1.59 (95% CI: 1.37-1.84) for late-onset cancer survivors. Compared to late-onset cancer survivors, early-onset cancer survivors exhibited higher late mortality relative to the general population, with an IRR for all-cause mortality of 1.49 (95% CI: 1.19-1.86). This difference was largely associated with malignant neoplasms (IRR: 1.63; 95% CI: 1.12-2.39) rather than other causes of death (IRR: 1.23; 95% CI: 0.95-1.60). When stratified by sociodemographic characteristics, the differences in excess late mortality varied across subgroups.

Our findings suggest that early-onset cancer survivors face higher late mortality relative to the general population compared to late-onset cancer survivors, driven by malignant neoplasms, with disparities exacerbated in socioeconomically disadvantaged groups.