title: Folate intake and MTHFR polymorphism C677T is not associated with ovarian cancer risk: evidence from the meta-analysis.
abstract: Folate is essential for DNA synthesis and methylation and implicated in the process of carcinogenesis. Several studies inconclusively suggested increased folate intake may reduce ovarian cancer risk. Studies concerning the association between C677T polymorphism in methylenetetrahydrofolate reductase (MTHFR), an important enzyme in folate metabolism, and ovarian cancer risk also resulted in no agreement. The meta-analysis was conducted based on current studies to assess the association between folate intake, the MTHFR C667T polymorphism and ovarian cancer risk. 1,158 cases out of 217,309 participants from four cohort studies, 4,519 cases and 6,031 controls from four case-control studies about folate intake along with 5,617 cases and 9,808 controls from 10 publications concerning the polymorphism were pooled, respectively. We detected no significant association between total folate (RR = 1.04, 95 % confidence interval (CI) = 0.87-1.23) or dietary folate (RR = 0.88, 95 % CI = 0.75-1.05) intake and ovarian cancer risk, and also no significant relationship was found between MTHFR C677T polymorphism and ovarian cancer risk (TT vs. CC: odds ratio (OR) = 1.15, 95 % CI = 0.90-1.46; CT vs. CC: OR = 1.04, 95 % CI = 0.94-1.16). Our analysis indicated neither folate intake nor MTHFR C677T polymorphism is related to altered susceptibility of ovarian cancer.
authors.affiliation: Key Laboratory of Food Safety Research, Institute for Nutritional Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Shanghai, 200031, China.
authors.forename: Chenglin
authors.initials: C
authors.lastname: Li
authors.forename: Peizhan
authors.initials: P
authors.lastname: Chen
authors.forename: Pingting
authors.initials: P
authors.lastname: Hu
authors.forename: Mian
authors.initials: M
authors.lastname: Li
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Li
authors.forename: He
authors.initials: H
authors.lastname: Guo
authors.forename: Jingquan
authors.initials: J
authors.lastname: Li
authors.forename: Ruiai
authors.initials: R
authors.lastname: Chu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
mesh_terms: D004032:Diet; D005260:Female; D005492:Folic Acid / Q000494:pharmacology*; D056726:Genetic Association Studies; D020022:Genetic Predisposition to Disease; D006801:Humans; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D008957:Models, Genetic; D010051:Ovarian Neoplasms / Q000201:enzymology* / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D012307:Risk Factors
chemical_list: D005492:Folic Acid; C573423:MTHFR protein, human; D042965:Methylenetetrahydrofolate Reductase (NADPH2)