Association of the MTHFR C677T polymorphism with primary brain tumor risk.

Methylenetetrahydrofolate reductase (MTHFR) gene plays key roles not only in folate metabolism but also in carcinogenesis. The single nucleotide polymorphism MTHFR C677T has been indicated in the development of various tumors. The effect of the MTHFR C677T polymorphism on brain tumors remains poorly understood. We performed the present meta-analysis and aimed to provide a better understanding of the pathogenesis of brain tumors. A literature search of the PubMed, Embase, Web of Science, and Wanfang databases was carried out for potential relevant publications. We calculated the pooled odds ratio (OR) with corresponding 95% confidence interval (95% CI) to assess the association of MTHFR C677T with the susceptibility to brain tumors. We also performed stratified analysis and sensitivity analysis to further estimate the genetic association. All statistical analyses were conducted by the use of STATA 11.0 (STATA Corporation, College Station, TX, USA). Eight case-control studies involving a total of 3,059 cases and 3,324 controls were retrieved according to the inclusion criteria. The overall ORs suggested that the MTHFR C677T variant can exert a risk effect on brain tumor development under the following contrast models (OR(TC vs. CC) = 1.14, 95% CI 1.02-1.27, P OR = 0.018; OR(TT + TC vs. CC)= 1.23, 95% CI 1.01-1.51, P(OR) = 0.043). No significant correlation was identified among the Caucasians, but not among the Asians. In addition, the TC genotype carriers were more susceptible to meningioma when compared with the CC genotype carriers (OR(TC vs. CC) = 1.38, 95% CI 1.15-1.65, P(OR) < 0.001). The MTHFR C677T polymorphism seemed to exert no effect on glioma risk. The current meta-analysis firstly provides evidence that the MTHFR C677T polymorphism may modify the risk for brain tumors, particularly meningioma. The role of the MTHFR C677T variant in brain tumor pathogenesis across diverse ethnicities needs further elucidation by more future studies with large sample size.