title: 5,10-Methylenetetrahydrofolate reductase polymorphisms and colon cancer risk: a meta-analysis.
abstract: Previous studies investigating the association between 5,10-methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and colon cancer risk have generated conflicting results. The aim of our meta-analysis was to clarify the precise association. A systematic literature search was conducted to identify all relevant studies. Pooled odds ratio (ORs) with 95% confidence interval (CI) were used to estimate the strength of the association. In this meta-analysis, a total of 13 articles, involving 5,386 cases and 8,017 controls met the inclusion criteria. Overall, a significant association was found between colon cancer risk and the MTHFR C667 polymorphism (TT vs CC+CT: OR=0.79; 95%CI=0.65-0.96; p=0.017). Stratification by ethnicity revealed that MTHFRC667 was associated with colon cancer risk in the non-Asian group (TT vs CC+CT:OR=0.77, 95%CI=0.68-0.89, p=0.000; TT vs CC: OR=0.84, 95%CI=0.73-0.97, p=0.016). Stratification by source of control indicated that MTHFR C667 also correlated with colon cancer risk in the population-based subgroup (TT vs CC: OR=0.85, 95%CI=0.74-0.97, p=0.017; TT vs CC+CT: OR=0.78, 95%CI=0.68-0.89, p=0.000) and hospital-based subgroup (TT vs CC+CT: OR=0.65, 95%CI=0.49-0.86, p=0.003). However, risk was significantly increased for MTHFR A1298C polymorphisms and colon cancer risk in hospital-based studies (C vs A: OR=1.52, 95%CI=1.26-1.83, p=0.000; CC+AC vs AA: OR=1.93, 95%CI=1.47-2.49, p=0.000) but reduced in population-based studies (CC vs AA: OR=0.83, 95%CI=0.70-0.99, p=0.042). In conclusion, the results of our meta-analysis suggest that the MTHFR C667 polymorphism is associated with reduced colon cancer risk, especially for non-Asian populations.
authors.affiliation: Epidemiology and Statistics, School of Public Health, Anhui Medical University, Hefei, China E-mail : ahmuydq@163.com, ydq@ahmu.edu.cn.
authors.forename: Xin-Yu
authors.initials: XY
authors.lastname: Fang
authors.forename: Wang-Dong
authors.initials: WD
authors.lastname: Xu
authors.forename: Qian
authors.initials: Q
authors.lastname: Huang
authors.forename: Xiao-Ke
authors.initials: XK
authors.lastname: Yang
authors.forename: Yan-Yan
authors.initials: YY
authors.lastname: Liu
authors.forename: Rui-Xue
authors.initials: RX
authors.lastname: Leng
authors.forename: Hai-Feng
authors.initials: HF
authors.lastname: Pan
authors.forename: Dong-Qing
authors.initials: DQ
authors.lastname: Ye
mesh_terms: D016022:Case-Control Studies; D003110:Colonic Neoplasms / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D011379:Prognosis; D012307:Risk Factors
chemical_list: C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)