A meta-analysis of alcohol consumption and thyroid cancer risk

// Xiaofei Wang 1,2 , Wenli Cheng 3 , Jingdong Li 2 and Jingqiang Zhu 1 1 Department of Thyroid and Breast Surgery, West China Hospital, Sichuan University, Chengdu, China 2 Department of General Surgery, Affiliated Hospital of North Sichuan Medical College, Nanchong, China 3 Department of Otolaryngology-Head and Neck Surgery, Affiliated Hospital of North Sichuan Medical College, Nanchong, China Correspondence to: Jingqiang Zhu, email: // Keywords : thyroid cancer; alcohol consumption; epidemiology; meta-analysis Received : April 03, 2016 Accepted : June 09, 2016 Published : June 30, 2016 Abstract Background: It is still inconclusive whether alcohol consumption affects the risk of thyroid cancer. We conducted a meta-analysis of available epidemiological data to address this issue. Results: Compared with nondrinkers, the pooled relative risks (RRs) and corresponding 95% confidential intervals (CIs) of thyroid cancer were 0.80 (95% CI 0.71-0.90) for any drinkers, 0.81 (95% CI 0.70-0.93) for light and 0.71 (95% CI 0.63-0.79) for moderate drinkers. The dose–response analysis suggested that there is no evidence of a dose-risk relationship between alcohol intaking and thyroid cancer risk ( P = 0.112). Methods: Eligible studies were identified by searching PubMed and EMbase databases. A total of 24 studies, included 9,990 cases with thyroid cancer, were included in this meta-analysis. We defined light alcohol intake as ≤ one drink/day and moderate as >one drink/day. The summary risk estimates were calculated by the random effects model. A dose-response analysis was also conducted for modeling the dose-risk relation. Conclusion: This meta-analysis confirmed an inverse association between alcohol consumption and thyroid cancer risk. Further studies are needed to better understand the potential mechanisms underlying this association.