title: Meta-analyses of the methylenetetrahydrofolate reductase C677T and A1298C polymorphisms and risk of head and neck and lung cancer.
abstract: Authors report the results of four meta-analyses of studies that examined the association between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and head and neck cancer (nine studies, 2076 cases and 4834 controls for C677T; four studies, 1439 cases and 3941 controls for A1298C), and lung cancer (ten studies, 5274 cases and 7435 controls for C677T; seven studies, 5098 cases and 6243 controls for A1298C). The summary odds ratio (OR) of head and neck cancer was 0.92 (95% CI: 0.76-1.11) for MTHFR 677 TT and 0.68 (95% CI: 0.37-1.26) for MTHFR 1298 CC. The OR of lung cancer was 1.22 [95% confidence interval (CI): 0.95-1.55] for MTHFR 677 TT and 1.07 (95% CI: 0.83-1.38) for MTHFR 1298 CC. Results from the meta-analysis of three studies on C677T stratified according to dietary folate intake showed an increased risk for individuals with low folate intake (OR = 1.37, 95% CI: 0.92-2.06 for head and neck and OR = 1.28, 95% CI: 0.97-1.68 for lung) versus high folate intake (OR = 0.85, 95% CI: 0.63-1.16 for head and neck, and OR = 0.94, 95% CI: 0.79-1.12 for lung). Despite the lack of formal statistical significance, these findings are consistent with the hypothesis that folate play a role in lung and head/neck carcinogenesis, and show the need to incorporate data on folate intake when interpreting results of MTHFR polymorphisms in relation to cancer risk.
authors.affiliation: Genetic Epidemiology and Molecular Biology Unit, Institute of Hygiene, Università Cattolica del Sacro Cuore, L.go F.Vito 1, 00168 Rome, Italy. sboccia@rm.unicatt.it
authors.forename: Stefania
authors.initials: S
authors.lastname: Boccia
authors.forename: Paolo
authors.initials: P
authors.lastname: Boffetta
authors.forename: Paul
authors.initials: P
authors.lastname: Brennan
authors.forename: Gualtiero
authors.initials: G
authors.lastname: Ricciardi
authors.forename: Francesco
authors.initials: F
authors.lastname: Gianfagna
authors.forename: Keitaro
authors.initials: K
authors.lastname: Matsuo
authors.forename: Cornelia M
authors.initials: CM
authors.lastname: van Duijn
authors.forename: Rayjean J
authors.initials: RJ
authors.lastname: Hung
mesh_terms: D020022:Genetic Predisposition to Disease; D006258:Head and Neck Neoplasms / Q000235:genetics*; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics*; D042965:Methylenetetrahydrofolate Reductase (NADPH2) / Q000235:genetics*; D011110:Polymorphism, Genetic; D012307:Risk Factors
chemical_list: D042965:Methylenetetrahydrofolate Reductase (NADPH2)