Association Between Alcohol Consumption and Risk of Nasopharyngeal Carcinoma: A Comprehensive Meta‐Analysis of Epidemiological Studies

Background Alcohol consumption is increasing all over the world, but whether it is an independent factor affecting the occurrence of nasopharyngeal carcinoma (NPC) is inconsistent in many studies. We aimed to explore the association between alcohol consumption and NPC risk by integrating existing evidence in a meta‐analysis. Methods We searched for relevant articles published up to August 2018 in PubMed, Cochrane Library, Web of Science, and China National Knowledge infrastructure (CNKI). The Newcastle–Ottawa scale was used to assess the quality of the included studies. Odds ratios (ORs) or relative risks were pooled to estimate the associations between alcohol consumption and NPC risk. Results The meta‐analysis of cohort studies showed no significant association between alcohol consumption and NPC, but pooled results from case–control studies indicated that ever drinking increased the probability of NPC versus nondrinking (OR = 1.10; 95% confidence interval [CI]: 1.01, 1.19). As compared with nondrinkers, high‐frequency drinking (≥7 times/wk) increased the NPC probability (OR = 1.29; 95% CI: 1.05, 1.53) and low‐frequency drinking (