Alcohol consumption and prostate cancer risk: a meta-analysis of the dose-risk relation.

Inconsistent results on the relationship between alcohol drinking and prostate cancer have been found. In order to provide a definite quantification of the dose-risk relation, we investigated the risk of prostate cancer at different levels of alcohol consumption, by conducting a meta-analysis of epidemiological studies. We performed a literature search using PubMed of all case-control and cohort studies published as original articles in English up to December 2010. We identified 50 case-control and 22 cohort studies, including a total of 52 899 prostate cancer cases. We derived pooled meta-analytic estimates using random-effects models, taking into account the correlation between estimates. We performed a dose-risk analysis using nonlinear random-effects meta-regression models. The overall relative risk for any alcohol drinking compared with non/occasional drinking was 1.06 [95% confidence interval (CI), 1.01-1.10]. The relative risks were 1.05 (95% CI, 1.02-1.08), 1.06 (95% CI, 1.01-1.11), and 1.08 (95% CI, 0.97-1.20) for light (≤1 drink/day), moderate (>1 to <4 drinks/day), and heavy alcohol drinking (≥4 drinks/day), respectively. This comprehensive meta-analysis provided no evidence of a material association between alcohol drinking and prostate cancer, even at high doses.