Alcohol drinking and colorectal cancer risk: an overall and dose-response meta-analysis of published studies.
Level 3 - non-randomized controlled study
Meta-analysis of observational cohort and case-control studies
PubMed 21307158 · doi:10.1093/annonc/mdq653
What was done
A meta-analysis of 27 cohort and 34 case-control studies identified from PubMed evaluated the association between alcohol consumption and colorectal cancer risk. Relative risks were pooled using random-effects models, and the dose-risk relationship was modeled using second-order fractional polynomials and random-effects meta-regression.
What was found
Moderate alcohol drinking (2 to 3 drinks per day) was associated with a relative risk of 1.21 (95% CI 1.13 to 1.28), with a higher risk in men (RR 1.24, 95% CI 1.13 to 1.37) than in women (RR 1.08, 95% CI 1.03 to 1.13; P for heterogeneity = 0.02). Heavy drinking (4 or more drinks per day) had a relative risk of 1.52 (95% CI 1.27 to 1.81), with a stronger association in Asian studies (RR 1.81, 95% CI 1.33 to 2.46; P for heterogeneity = 0.04). Dose-risk analysis showed relative risks of 1.07 (95% CI 1.04 to 1.10) for 10 g per day, 1.38 (95% CI 1.28 to 1.50) for 50 g per day, and 1.82 (95% CI 1.41 to 2.35) for 100 g per day of alcohol. Numerical estimates for light drinking (1 or fewer drinks per day) were not reported in the abstract.
Why it matters
This study quantifies a dose-dependent increase in colorectal cancer risk for alcohol consumption above one drink daily, showing notable variation by sex and geographic region.
Limits
The primary evidence comes from observational studies subject to confounding and exposure misclassification from self-reported intake. The abstract does not provide the total participant count across the 61 included studies.
Cited by
- partial Consuming fewer than 7 drinks per week increases the relative risk for breast cancer by ~4%, colorectal cancer by ~9%, oral and pharyngeal cancer by 13% to 17%, and esophageal cancer and malignant melanoma by 26% to 44%.