Alcohol intake and renal cell cancer risk: a meta-analysis.

BACKGROUND: An inverse association between alcoholic beverage intake and risk of renal cell cancer has been suggested in recent studies. METHODS: We examined the association between alcoholic beverages and renal cell cancer risk in a meta-analysis. We identified relevant studies by searching the database of PubMed, EMBASE, and MEDLINE published through August 2011. We combined the study-specific relative risks (RRs) using a random-effects model. RESULTS: A total of 20 case-control studies, 3 cohort studies, and 1 pooled analysis of cohort studies were included in the meta-analysis. We observed that alcoholic beverage intake was associated with a lower risk of renal cell cancer in combined analysis of case-control and cohort studies; for total alcoholic beverage intake, combined RRs (95% confidence intervals) comparing top with bottom categories were 0.76 (0.68-0.85) in case-control studies, and 0.71 (0.63-0.78) in cohort studies (P for difference by study design=0.02). The inverse associations were observed for both men and women and for each specific type alcoholic beverage (beer, wine, and liquor). Also, we found that one drink per day of alcoholic beverage conferred the reduction in renal cell cancer risk, but further drinking above that level did not add benefit. CONCLUSION: The findings from our meta-analysis support the hypothesis that alcoholic beverage intake is inversely associated with a lower risk of renal cell cancer, with moderate consumption conferring the protection and higher consumption conferring no additional benefits.