The Association between MTHFR Gene Polymorphisms and Hepatocellular Carcinoma Risk: A Meta-Analysis

BACKGROUND The association between methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and hepatocellular carcinoma (HCC) risk was inconsistent and underpowered. To clarify the effects of MTHFR gene polymorphisms on the risk of HCC, a meta-analysis of all available studies relating C677T and/or A1298C polymorphisms of MTHFR gene to the risk of HCC was conducted. METHODS The authors searched PubMed, EMBASE, Cochrane Library, Web of Science, and Chinese Biomedical Literature database (CBM) for the period up to July 2012. Data were extracted by two independent authors and pooled odds ratio (OR) with 95% confidence interval (CI) was calculated. Metaregression and subgroup analyses were performed to identify the source of heterogeneity. RESULTS Finally, 12 studies with 2,351 cases and 4,091 controls were included for C677T polymorphism and 6 studies with 1,333 cases and 1,878 controls were included for A1298C polymorphism. With respect to A1298C polymorphism, significantly decreased HCC risk was found in the overall population (CC vs. AA: OR = 0.660, 95%CI 0.460-0.946, P = 0.024; recessive model: OR = 0.667, 95%CI = 0.470-0.948, P = 0.024). In subgroup analyses, significantly decreased HCC risk was found in Asian population (CC vs. AA: OR = 0.647, 95%CI = 0.435-0.963; P = 0.032) and population-based studies (CC vs. AA: OR = 0.519, 95%CI = 0.327-0.823; P = 0.005). With respect to C677T polymorphism, no significant association with HCC risk was demonstrated in overall and stratified analyses. CONCLUSIONS We concluded that MTHFR A1298C polymorphism may play a protective role in the carcinogenesis of HCC. Further large and well-designed studies are needed to confirm this association.