Meta-analysis of the ADH1B and ALDH2 Polymorphisms and the Risk of Colorectal Cancer in East Asians

Objective The aldehyde dehydrogenase 2 (ALDH2) and alcohol dehydrogenase 1B (ADH1B) genes have been implicated in the development of colorectal cancer (CRC). However, the results are inconsistent. In this study, a meta-analysis was performed to assess the associations between the ALDH2 and ADH1B polymorphisms and the risk of CRC. Methods Relevant studies were identified using PubMed, Web of Science and CNKI up to February, 2013. The pooled odds ratio (OR) with a 95% confidence interval (CI) was calculated using the fixed-or random-effects model. Results A total of 11 case-controlled studies were selected. Of these, 11 studies included 2,893 cases and 3,817 controls concerning the ALDH2 Glu487Lys polymorphism and six studies included 1,864 cases and 3,502 controls concerning the ADH1B polymorphism. The results indicated that there was a statistically significant link between the ALDH2 polymorphism and the risk of CRC (Glu/Lys+Lys/Lys vs. Glu/Glu: OR=0.87, 95% CI: 0.78-0.96, p=0.10; Glu/Lys vs. Glu/Glu: OR=0.87, 95% CI: 0.77-0.97, p=0.38); however, no significant associations were observed between the ADH1B polymorphism and the risk of CRC win any of the genetic models. Conclusion This meta-analysis demonstrated that the ALDH2 polymorphism, but not the ADH1B polymorphism, significantly increases the risk of CRC in East Asians.