REVIEW ARTICLE A Meta-analysis of Alcohol Drinking and Oral and Pharyngeal Cancers: Results from Subgroup Analyses

Abstract — Aims: To quantify the magnitude of the association between alcohol and oral and pharyngeal cancer (OPC) by sex, smoking habits, type of alcoholic beverage and other factors. Methods: We combined findings from all case–control and cohort studies published until September 2010 and present in this article the results classified by these factors, using a meta-analytic ap-proach. Summary relative risks (RRs) were obtained using random-effects models; heterogeneity was assessed using the χ2 test. Results: The association between alcohol and OPC risk was similar in men and women, with similar dose–response relationships. No notable differences were found with respect to geographic area and other factors, both for drinking overall and heavy (≥4 drinks/ day) drinking. Among never/non-current smokers, the pooled RRs were 1.32 (95 % confidence interval, CI, 1.05–1.67) for drinking, and 2.54 (95 % CI, 1.80–3.58) for heavy drinking. The corresponding RRs in smokers were 2.92 (95 % CI, 2.31–3.70) and 6.32 (95 % CI, 5.05–7.90). The pooled RRs for any drinking irrespective of smoking were 2.12 (95 % CI, 1.37–3.29) for wine-, 2.43 (95%