Associations of alcohol use and smoking with early-onset colorectal cancer

The incidence of early-onset CRC (EOCRC) has been increasing. Researchers in Germany synthesised findings on the association of smoking and alcohol consumption with EOCRC in a systematic review and meta-analysis.
PubMed and Web of Science were searched for observational studies on the association of smoking or alcohol consumption with EOCRC. Meta-analyses were performed, including several subgroup analyses, to examine the association of alcohol consumption and smoking, respectively, with the risk of EOCRC.
Eleven studies were included for alcohol consumption and 12 for smoking. Alcohol use was found to be a risk factor for EOCRC, with a pooled odds ratio (OR) of 1.39 (95% confidence interval (CI) 1.14-1.69). A dose-response model revealed a positive association between the amount of ethanol consumed and the risk of EOCRC (OR per 10g/d ethanol increase 1.02, 95% CI 1.01-1.08). Smoking (ever or current combined) was also found to be a significant risk factor for EOCRC (OR 1.39, 95% CI 1.20-1.59).
The study concludes that alcohol consumption and smoking are significant risk factors for EOCRC and should be addressed in the context of prevention.
Source: Wieser J, Hoffmeister M, Brenner H, Mons U. Associations of alcohol use and smoking with early-onset colorectal cancer – A systematic review and meta-analysis. Clinical Colorectal Cancer, 2025, ISSN 1533-0028.