Male sex (34% higher risk) and Hispanic ethnicity (34% higher risk) were associated with increased early-onset colorectal cancer risk.
A population-based nested case-control study in California, published in Cancer, examined associations between demographic, birth, and parental characteristics and risk of colorectal cancer diagnosed before age 40.
Key Findings
Higher birth weight was associated with increased risk only among females: a 10% rise per 500-gram increase.
Having a father aged 35 or older was associated with increased risk only among females.
Having a foreign-born mother was associated with lower risk, particularly among males.
Study Details
The study included 1,221 early-onset colorectal cancer cases diagnosed between ages 0–39 (mean age 29) and 61,050 matched controls. Data were sourced from California birth records and the state's cancer registry.
Limitations
- Findings may not generalize to cases diagnosed between ages 40–49.
- Subgroup analysis for ages 0–19 had few cases; parental education data missing for ~70% of participants.
- Unmeasured factors (e.g., maternal obesity) may have influenced results; multiple comparisons could yield false positives.