title: Methylenetetrahydrofolate reductase genetic polymorphisms and esophageal squamous cell carcinoma susceptibility: a meta-analysis of case-control studies.
abstract: BACKGROUND
  Genetic factors and environmental factors play a role in pathogenesis of esophageal squamous cell carcinoma (ESCC). Previous studies regarding the association of folate intake and Methylenetetrahydrofolate reductase C677T polymorphism with ESCC was conflicting. We conducted a meta-analysis to investigate the association of MTHFR C677T and folate intake with esophageal cancer risk.
  
  
  METHODS
  MEDLINE, EMBASE and the Chinese Biomedical Database were searched in our study. The quality of studies were evaluated by predefined scale, and The association of polymorphisms of MTHFR C677T and folate intake and ESCC risk was estimated by Odds ratio (ORs) with 95% confidence intervals (CIs).
  
  
  RESULTS
  19 studies (4239 cases and 5575 controls) were included for meta-analysis. A significant association was seen between individuals with MTHFR 677 CT [OR(95%)=1.47(1.32-1.63)] and TT [OR(95%)=1.69(1.49-1.91)] genotypes and ESCC risk (p<0.05). Low intake of folate had significantly higher risk of esophageal cancer among individuals with CT/TT genotype [OR(95%)=1.65(1.1-2.49)], while high intake of folate did not find significant high risk of esophageal cancer among individuals with CT/TT genotype [OR(95%)=1.64 (0.82-3.26)].
  
  
  CONCLUSIONS
  Our meta-analysis indicated the folate intake and MTHFR 677CT/TT are associated with the risk of ESCC, and folate showed a significant interaction with polymorphism of MTHFR C677T.
authors.affiliation: West China School of Public Heath, Sichuan University, Chengdu, China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Wen
authors.forename: Shu-Juan
authors.initials: SJ
authors.lastname: Yang
authors.forename: Jian-Xing
authors.initials: JX
authors.lastname: Zhang
authors.forename: Xin-Yue
authors.initials: XY
authors.lastname: Chen
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D016022:Case-Control Studies; D016001:Confidence Intervals; D004032:Diet; D004938:Esophageal Neoplasms / Q000235:genetics*; D005492:Folic Acid; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D016017:Odds Ratio; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors
chemical_list: D005492:Folic Acid; D042965:Methylenetetrahydrofolate Reductase (NADPH2)