Sex differences in survival outcomes of early-onset colorectal cancer

Colorectal cancer (CRC) is one of the most fatal cancers in the United States. Although the overall incidence and mortality rates are declining, an alarming rise in early-onset colorectal cancer (EOCRC), defined as CRC diagnosis in patients aged < 50 years, was previously reported. Our study focuses on analyzing sex-specific differences in survival among EOCRC patients and comparing sex-specific predictors of survival in both males and females in the United States. We retrieved and utilized data from the Surveillance, Epidemiology, and End Results (SEER) program. EOCRC patients, between the ages of 20 and 49, were exclusively included. We conducted thorough survival analyses using Kaplan-Meier curves, log-rank tests, Cox regression models, and propensity score matching to control for potential biases. Our study included 58,667 EOCRC patients (27,662 females, 31,005 males) diagnosed between 2000 and 2017. The baseline characteristics at the time of diagnosis were significantly heterogeneous between males and females. Males exhibited significantly worse overall survival (OS), cancer-specific survival (CSS), and noncancer-specific survival (NCSS) in comparison to females in both the general cohort, and the matched cohort. Predictors of survival outcomes generally followed a similar pattern in both sexes except for minor differences. In conclusion, we identified sex as an independent prognostic factor of EOCRC, suggesting disparities in survival between sexes. Further understanding of the epidemiological and genetic bases of these differences could facilitate targeted, personalized therapeutic approaches for EOCRC.