Genetic polymorphisms of ALDH2 and ADH2 are not associated with risk of hepatocellular carcinoma among East Asians

The aldehyde dehydrogenase 2 (ALDH2) and alcohol dehydrogenase 2 (ADH2) genes have been implicated in the development of hepatocellular carcinoma (HCC). However, the results have been inconsistent. In this study, we performed a meta-analysis to clarify the associations between polymorphisms of ALDH2 and ADH2 genes and HCC. Published literatures from PubMed and Embase were retrieved. Pooled odds ratio (OR) with 95% confidence interval (CI) was calculated using fixed- or random-effects model. Ten studies including 1,231 HCC cases and 1,849 controls were included in the meta-analysis of the association between ALDH2 polymorphism and HCC risk. The results indicated that ALDH2 polymorphism was not significantly associated with risk of HCC (homogeneous co-dominant model: OR = 0.99, 95% CI 0.72-1.34; heterogeneous co-dominant model: OR = 0.90, 95% CI 0.75-1.08; dominant model: OR = 0.91, 95% CI 0.70-1.18; recessive model: OR = 1.11, 95% CI 0.66-1.87). In addition, four studies including 518 cases and 607 controls were included in the meta-analysis of the association between ADH2 polymorphism and HCC risk. There was no association between ADH2 polymorphism and HCC risk (homogeneous co-dominant model: OR = 0.93, 95% CI 0.58-1.51; heterogeneous co-dominant model: OR = 1.39, 95% CI 0.87-2.23; dominant model: OR = 1.19, 95% CI 0.76-1.88; recessive model: OR = 0.91, 95% CI 0.54-1.54). Further analysis suggested that the ALDH2 polymorphism-alcohol interaction was marginally associated with HCC risk under the dominant model (OR = 2.05, 95% CI 1.01-4.17). However, the result was not robust by sensitivity analysis. The results from the present meta-analysis indicated that there was no significant association between ALDH2 polymorphism, ADH2 polymorphism, or ALDH2 polymorphism-alcohol intake interaction and HCC risk in the East Asians.