Methylenetetrahy drofolate reductase C677T polymorphism and susceptibility to esophageal cancer: a meta-analysis

Objective To evaluate the effect of the methylenetetrahy drofolate reductase C677T genetic polymorphism（ MTHFR C677T） on the risk of esophageal cancer. Methods A total of 11 studies（ 2 269 cases and 3 367 controls） regarding MTHFR C677T between 2001 and 2012 were identified through researching MEDLINE,EMBASE,and Chinese Biomedical Database. A meta-analysis was performed to obtain summary estimated odd ratios（ OR） and 95% confidence interval（ 95% CI） of MTHFR C677T for esophageal cancer. Results A significant association was observed between MTHFR 677 CT（ adjusted OR95% CI= 1. 431. 06- 1. 93） and TT（ adjusted OR95% CI= 1. 681. 16- 2. 45〗） genotypes and esophageal cancer. The meta-regression analysis showed that the effect of MTHFR 677 CT and TT increased with the level of alcohol and tobacco consumption. The MTHFR 677 TT genotype showed a decreased risk of esophageal cancer in the high folate intake group. Stratified analysis results showed that CT（ adjusted OR95% CI= 1. 571. 13- 2. 20） and TT（ adjusted OR95% CI= 1. 811. 20- 2. 72） genotypes conferred an increased risk of esophagus cancer only in the design of population-based case-control study,and the genotype of TT was a risk factor of esophageal squamous cell carcinoma（ adjusted OR95% CI= 1. 951. 33- 2. 86）. Conclusion MTHFR C677T polymorphism was significantly associated with esophageal cancer,and subjects with CT or TT genotype have increased risk of esophageal cancer.