Association between MTHFR 677C>T polymorphism and risk of gliomas: evidence from a meta-analysis.

Folate metabolism plays an important role in carcinogenesis. Methylenetetrahydrofolate reductase (MTHFR) 677C>T polymorphism is a genetic alteration in an enzyme involved in folate metabolism, but its effect on risk of gliomas is still uncertain. To shed some light on these contradictory results from previous studies, we performed a meta-analysis of published data investigating the association between MTHFR 677C>T polymorphism and risk of gliomas. PubMed, Embase, and Web of Science databases were searched for eligible case-control studies. Odds ratios (ORs) and 95 % confidence intervals (CIs) were used to assess the strength of this association. Ten individual case-control studies from six publications with a total of 1,786 cases and 2,076 controls were included into this meta-analysis. There was no obvious heterogeneity under all comparison models of this meta-analysis. Meta-analysis of those ten studies showed that there was no obvious association between MTHFR 677C>T polymorphism and risk of gliomas under all five genetic models (for T versus C, OR = 1.00, 95 % CI 0.90-1.12, P OR = 0.959; for TT versus CC, OR = 1.02, 95 % CI 0.82-1.27, P OR = 0.870; for CT versus CC, OR = 1.02, 95 % CI 0.89-1.18, P OR = 0.733; for TT+CT versus CC, OR = 1.02, 95 % CI 0.90-1.16, P OR = 0.781; for TT versus CT+CC, OR = 0.99, 95 % CI 0.81-1.21, P OR = 0.902). There was also no obvious association between MTHFR 677C>T polymorphism and risk of gliomas in the sensitivity and subgroup analyses of Caucasians. There was no risk of publication bias in this meta-analysis. The evidence from our meta-analysis supports that there is no association between MTHFR 677C>T polymorphism and risk of gliomas.