The association between the C677T polymorphism in MTHFR gene and the risk of thyroid cancer: a meta-analysis.

OBJECTIVES Methylenetetrahydrofolate reductase (MTHFR) enzyme plays an important role in folate metabolism and MTHFR C677T polymorphism has been suggested as a risk factor to various cancers. It is a common genetic alteration and may affect the host susceptibility to thyroid cancer. The aim of this study was to investigate the association between MTHFR C677T polymorphism and thyroid cancer risk by performing a meta-analysis. MATERIALS AND METHODS PubMed, EMbase, CNKI and Wanfang databases were searched for case-control studies investigating the association between MTHFR C677T polymorphism and thyroid cancer risk. OR with 95%CI was used to assess this possible association. Four individual case-control studies with a total of 360 cases and 900 controls were included into this meta-analysis. RESULTS Meta-analyses showed there was significant association between MTHFR C677T polymorphism and thyroid cancer risk: TT vs. CC: OR = 2.06, 95% CI = 1.04-4.10, p = 0.04; T vs. C: OR = 2.06, 95% CI = 1.97-3.77, p = 0.04. CONCLUSIONS This meta-analysis supports an association between MTHFR C677T polymorphism and thyroid cancer risk. Further studies with large sample size and careful design are needed to identify this association more comprehensively.