Male sex and Hispanic ethnicity linked to 34-43% higher early-onset colorectal cancer risk in California nested case-control study

The nested case-control analysis matched cases born 1988-2021 to 61,050 controls without cancer. Key associations included a 10% risk increase per 500g higher birth weight among females and 56% higher risk with paternal age 35 or older. Foreign-born maternal status correlated with 15% lower risk. No associations emerged for other birth or parental factors examined.

These findings align with broader U.S. trends of rising early-onset colorectal cancer incidence, where observational data from SEER registries show disproportionate increases among younger adults of Hispanic descent and males. The paternal age signal echoes patterns seen in other malignancies potentially tied to de novo mutations, while birth weight links suggest prenatal growth factors may influence colorectal carcinogenesis decades later.

The study design cannot establish causation or rule out residual confounding from unmeasured lifestyle or environmental exposures that have shifted across birth cohorts. Mechanisms remain speculative and require integration with molecular profiling of tumors arising in these demographic groups.

Future work should replicate these associations in diverse national cohorts and incorporate longitudinal data on obesity, diet, and antibiotic exposure to clarify whether the identified factors operate through modifiable pathways.