BACKGROUND: Folate intake may be related to decreased risk of colorectal cancer and adenomas. Methylenetetrahydrofolate reductase (MTHFR) is a key regulatory enzyme in folate metabolism. We examined the relation between plasma folate status and colorectal adenomas with reference to effect modification by the genetic polymorphism (C677T) of MTHFR. METHODS: Study subjects were middle-aged Japanese men: 177 cases of colorectal adenomas and 192 controls with normal total colonoscopy. Statistical adjustment was made for hospital, rank in the Self Defense Forces, alcohol use, smoking, and body mass index. RESULTS: Plasma folate levels were slightly lower in adenoma cases than in controls. Adjusted odds ratio (OR) for high (>5.50 ng/ml) versus low plasma folate levels was 0.72 (95% CI: 0.46-1.14). As compared with subjects with the CC or CT genotype having low plasma folate levels, those with the TT genotype showed a decreased risk of colorectal adenomas when they had high levels of plasma folate (adjusted OR = 0.58, 95% CI: 0.21-1.61), and an increased risk when they had low folate levels (adjusted OR = 2.13, 95% CI: 0.82-5.54). There was no clear relation between plasma folate and colorectal adenomas among those with the CC or CT genotype. CONCLUSIONS: The findings suggest an interaction between folate and the MTHFR genotype on colorectal adenomas.
BACKGROUND:Folate intake may be related to decreased risk of colorectal cancer and adenomas. Methylenetetrahydrofolate reductase (MTHFR) is a key regulatory enzyme in folate metabolism. We examined the relation between plasma folate status and colorectal adenomas with reference to effect modification by the genetic polymorphism (C677T) of MTHFR. METHODS: Study subjects were middle-aged Japanese men: 177 cases of colorectal adenomas and 192 controls with normal total colonoscopy. Statistical adjustment was made for hospital, rank in the Self Defense Forces, alcohol use, smoking, and body mass index. RESULTS: Plasma folate levels were slightly lower in adenoma cases than in controls. Adjusted odds ratio (OR) for high (>5.50 ng/ml) versus low plasma folate levels was 0.72 (95% CI: 0.46-1.14). As compared with subjects with the CC or CT genotype having low plasma folate levels, those with the TT genotype showed a decreased risk of colorectal adenomas when they had high levels of plasma folate (adjusted OR = 0.58, 95% CI: 0.21-1.61), and an increased risk when they had low folate levels (adjusted OR = 2.13, 95% CI: 0.82-5.54). There was no clear relation between plasma folate and colorectal adenomas among those with the CC or CT genotype. CONCLUSIONS: The findings suggest an interaction between folate and the MTHFR genotype on colorectal adenomas.
Authors: A Joan Levine; Kristin Wallace; Shirley Tsang; Robert W Haile; Fred Saibil; Dennis Ahnen; Bernard F Cole; Elizabeth L Barry; David J Munroe; Iqbal U Ali; Per Ueland; John A Baron Journal: Cancer Epidemiol Biomarkers Prev Date: 2008-09 Impact factor: 4.254
Authors: A Joan Levine; Won Lee; Jane C Figueiredo; David V Conti; David J Vandenberg; Brian D Davis; Christopher K Edlund; Susanne M Henning; David Heber; Mariana C Stern; Robert W Haile Journal: Cancer Causes Control Date: 2011-01-28 Impact factor: 2.506