Methylenetetrahydrofolate reductaseC677T and A1298Cpolymorphisms and gastric cancer susceptibility: an updated meta-analysis.

Abstract

Widely regarded as one of the most prevalent malignancies worldwide, gastric cancer(GC) is a common clinical condition of the digestive system.Reviewing14 meta-analyses that evaluated the association between Methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and GC risk, we observed inconsistent results, and the credibility of the significant correlation between the statistical results was ignored. With the aim of further exploring the association between MTHFRC677Tand CA1298Cand the risk of GC, we searched electronic databases, pooling 43 relevant studies and calculating odds ratios (ORs)and corresponding 95% confidence intervals (CIs)for each of the five genetic models. Subgroup and regression analyses were performed to look for sources of heterogeneity and publication bias was assessed by funnel plots.To assess the plausibility of statistically significant associations, we used the FPRP test and the Venice criteria. Overall data analysis showed that MTHFRC677Tpolymorphismwas significantly associated with GC risk, especially in Asians, while MTHFRCA1298Cpolymorphism was not associatedwith GC risk. However, insubgroup analysisby hospital-based controls, we found that MTHFRCA1298Cmight be a protective factor for GC. After credibility assessment, the statistical association between MTHFRC677Tand GCsusceptibility study was classified as "less credible positive result", while the result of MTHFRCA1298Cwas considered unreliable.In summary, this study strongly suggests that MTHFR, C677Tand CA1298Cpolymorphisms are not significantly associated with the GC risk.