title: Methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and gastric cancer susceptibility.
abstract: OBJECTIVE
  To identify the association between methylenetetrahydrofolate reductase (MTHFR) polymorphisms and gastric cancer (GC) susceptibility.
  
  
  METHODS
  Systematic searches were performed on the electronic databases PubMed, ISI, Web of knowledge, CNKI and Wanfang, as well as manual searching of the references of the identified articles. A total of 26 papers were included in this meta-analysis. Overall and subgroup analyses were performed. Odds ratio (OR) and 95%CI were used to evaluate the associations between MTHFR polymorphisms and GC risk. The I (2) statistics were used to evaluate between-study heterogeneity. Sensitivity analysis was also performed.
  
  
  RESULTS
  Increased risk was found for the MTHFR C677T polymorphism under four genetic models (TT + CT vs CC: OR = 1.23, P = 0.002; T vs C: OR = 1.15, P = 0.001; TT vs CC: OR = 1.37, P = 0.0005; TT vs CT + CC: OR = 1.17, P = 0.0008). Subgroup analysis by ethnicity suggested that C677T polymorphism conferred a risk of GC in eastern but not in western populations. Stratification by tumor site showed an association between the C677T polymorphism and gastric cardia cancer and non-cardia GC in the worldwide population and in eastern populations. Regardless of comparisons with controls or diffuse-type GC, a positive association was found for the C677T polymorphism and an increased risk of intestinal-type GC in the whole population and in western populations. With regard to the A1298C polymorphism, we found that genotype CC was significantly decreased and conferred protection against GC in eastern populations (CC vs AA: OR = 0.44, P = 0.03; CC vs AC + AA: OR = 0.46, P = 0.04).
  
  
  CONCLUSIONS
  MTHFR C677T polymorphism is a risk factor for GC, and the A1298C polymorphism may be a protective factor against GC in eastern populations.
authors.affiliation: Lei-Zhou Xia, Peng-Cheng Jiang, Gui Ma, Xue-Feng Bu, Yong-Jun Zhang, Feng Yu, Hua Li, Department of General Surgery, Affiliated People's Hospital, Jiangsu University, Zhenjiang 212002, Jiangsu Province, China.
authors.forename: Lei-Zhou
authors.initials: LZ
authors.lastname: Xia
authors.affiliation: Lei-Zhou Xia, Peng-Cheng Jiang, Gui Ma, Xue-Feng Bu, Yong-Jun Zhang, Feng Yu, Hua Li, Department of General Surgery, Affiliated People's Hospital, Jiangsu University, Zhenjiang 212002, Jiangsu Province, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Lei-Zhou Xia, Peng-Cheng Jiang, Gui Ma, Xue-Feng Bu, Yong-Jun Zhang, Feng Yu, Hua Li, Department of General Surgery, Affiliated People's Hospital, Jiangsu University, Zhenjiang 212002, Jiangsu Province, China.
authors.forename: Xiao-Zhou
authors.initials: XZ
authors.lastname: Xu
authors.affiliation: Lei-Zhou Xia, Peng-Cheng Jiang, Gui Ma, Xue-Feng Bu, Yong-Jun Zhang, Feng Yu, Hua Li, Department of General Surgery, Affiliated People's Hospital, Jiangsu University, Zhenjiang 212002, Jiangsu Province, China.
authors.forename: Peng-Cheng
authors.initials: PC
authors.lastname: Jiang
authors.affiliation: Lei-Zhou Xia, Peng-Cheng Jiang, Gui Ma, Xue-Feng Bu, Yong-Jun Zhang, Feng Yu, Hua Li, Department of General Surgery, Affiliated People's Hospital, Jiangsu University, Zhenjiang 212002, Jiangsu Province, China.
authors.forename: Gui
authors.initials: G
authors.lastname: Ma
authors.affiliation: Lei-Zhou Xia, Peng-Cheng Jiang, Gui Ma, Xue-Feng Bu, Yong-Jun Zhang, Feng Yu, Hua Li, Department of General Surgery, Affiliated People's Hospital, Jiangsu University, Zhenjiang 212002, Jiangsu Province, China.
authors.forename: Xue-Feng
authors.initials: XF
authors.lastname: Bu
authors.affiliation: Lei-Zhou Xia, Peng-Cheng Jiang, Gui Ma, Xue-Feng Bu, Yong-Jun Zhang, Feng Yu, Hua Li, Department of General Surgery, Affiliated People's Hospital, Jiangsu University, Zhenjiang 212002, Jiangsu Province, China.
authors.forename: Yong-Jun
authors.initials: YJ
authors.lastname: Zhang
authors.affiliation: Lei-Zhou Xia, Peng-Cheng Jiang, Gui Ma, Xue-Feng Bu, Yong-Jun Zhang, Feng Yu, Hua Li, Department of General Surgery, Affiliated People's Hospital, Jiangsu University, Zhenjiang 212002, Jiangsu Province, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Yu
authors.affiliation: Lei-Zhou Xia, Peng-Cheng Jiang, Gui Ma, Xue-Feng Bu, Yong-Jun Zhang, Feng Yu, Hua Li, Department of General Surgery, Affiliated People's Hospital, Jiangsu University, Zhenjiang 212002, Jiangsu Province, China.
authors.forename: Ke-Sen
authors.initials: KS
authors.lastname: Xu
authors.affiliation: Lei-Zhou Xia, Peng-Cheng Jiang, Gui Ma, Xue-Feng Bu, Yong-Jun Zhang, Feng Yu, Hua Li, Department of General Surgery, Affiliated People's Hospital, Jiangsu University, Zhenjiang 212002, Jiangsu Province, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Li
mesh_terms: D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D016017:Odds Ratio; D010641:Phenotype; D011110:Polymorphism, Genetic; D065840:Protective Factors; D018570:Risk Assessment; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000201:enzymology / Q000208:ethnology / Q000235:genetics* / Q000473:pathology
chemical_list: C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)
keywords: Gastric cancer; Meta-analysis; Methylenetetrahydrofolate reductase; Polymorphism