title: MTHFR genotype and colorectal adenoma recurrence: data from a double-blind placebo-controlled clinical trial.
abstract: Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme in folate metabolism. We assessed the association between two common MTHFR variants, 677C>T and 1298A>C, and adenoma recurrence in the context of a randomized double- blind clinical trial of aspirin use and folate supplementation. We used generalized linear regression to estimate risk ratios and 95% confidence intervals (95% CI) for recurrence, adjusting for age, sex, clinical center, follow-up time, and treatment status. Neither MTHFR polymorphism was associated with overall or advanced adenoma recurrence. Compared with those with two wild-type alleles, the relative risk for advanced adenoma was 0.75 (95% CI, 0.36-1.55) for the MTHFR 677 TT genotype and 1.16 (95% CI, 0.58-2.33) for the MTHFR 1298 CC genotype. The effect of folate supplementation on recurrence risk did not differ by genotype. Our findings indicate that the MTHFR genotype does not change adenoma risk in a manner similar to its effect on colorectal cancer, and does not modify the effect of folate supplementation on metachronous adenoma risk.
authors.affiliation: Department of Preventive Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA. ajoanlev@usc.edu
authors.forename: A Joan
authors.initials: AJ
authors.lastname: Levine
authors.forename: Kristin
authors.initials: K
authors.lastname: Wallace
authors.forename: Shirley
authors.initials: S
authors.lastname: Tsang
authors.forename: Robert W
authors.initials: RW
authors.lastname: Haile
authors.forename: Fred
authors.initials: F
authors.lastname: Saibil
authors.forename: Dennis
authors.initials: D
authors.lastname: Ahnen
authors.forename: Bernard F
authors.initials: BF
authors.lastname: Cole
authors.forename: Elizabeth L
authors.initials: EL
authors.lastname: Barry
authors.forename: David J
authors.initials: DJ
authors.lastname: Munroe
authors.forename: Iqbal U
authors.initials: IU
authors.lastname: Ali
authors.forename: Per
authors.initials: P
authors.lastname: Ueland
authors.forename: John A
authors.initials: JA
authors.lastname: Baron