Risk factors for Ki-ras protooncogene mutation in sporadic colorectal adenomas

摘要: The Ki- ras protooncogene frequently is mutated in colorectal adenocarcinomas, but the etiology of this molecular event uncertain. We investigated association between variables known or suspected to be related risk for cancer and occurrence mutations adenomas. This study was conducted among 678 male female participants, 40–80 years age, enrolled a phase III trial testing effects wheat bran fiber supplement on adenoma recurrence. Exposure information factors interest assessed through self-administered questionnaires. Mutations codons 12 13 were analyzed baseline adenomas 0.5 cm larger by PCR amplification followed direct sequencing. Eighteen percent (120 678) participants had one more adenoma(s) with mutations. A higher associated increasing age lower intake total folate. odds ratio (OR) individuals >72 1.98 [95% confidence interval (CI) = 1.19–3.27; P trend 0.008] compared those less than 65 age. Compared tertile folate, upper an ∼50% having mutation-positive (OR 0.52; 95% CI 0.30–0.88; 0.02). There suggestion stronger inverse folate G→T transversions 0.41; 0.20–0.87) G→A transitions 0.61; 0.31–1.21), although CIs associations overlap. results these analyses suggest that protective effect colon observed published studies may mediated folate’s