Diet, lifestyle and risk of K-ras mutation-positive and -negative colorectal adenomas

Int J Cancer. 2006 Jul 15;119(2):398-405. doi: 10.1002/ijc.21839.


K-ras mutation-positive (K-ras+) and -negative (K-ras-) colorectal adenomas may differ clinically and pathologically. As environmental compounds may cause mutations in the growth-related K-ras oncogene or affect clonal selection depending on mutational status, we evaluated whether the aetiology of K-ras+ and K-ras- adenomas differs. K-ras mutations in codons 12 and 13 were assessed in colorectal adenoma tissue (K-ras+: n = 81, K-ras-: n = 453). Dietary and lifestyle data were collected through questionnaires that were also administered to 709 polyp-free controls. Multiple logistic regression analyses showed that intake of vitamin B2 and monounsaturated fat were differently associated with risk of K-ras+ and K-ras- adenomas; vitamin B2 was inversely associated with K-ras- (highest vs. lowest tertile: odds ratio (OR) = 0.70, 95% confidence interval (CI) = 0.50-0.97, p trend = 0.020), but not with K-ras+ adenomas, and a positive association with monounsaturated fat was confined to K-ras- adenomas (OR = 1.57, 95% CI = 1.06-2.34, p trend = 0.029). Besides, potential, not statistically significant, differences in risk arose because red meat was distinctly positively associated with K-ras+ adenomas (OR = 1.70, 95% CI = 0.94-3.09, p trend = 0.061); total dietary and polyunsaturated fat tended to be inversely associated with risk of K-ras+ but not of K-ras- adenomas; inverse associations with dairy products, calcium, protein and tea were confined to K-ras- adenomas, and smoking was more markedly positively associated with K-ras- adenomas. No differences in risk of K-ras+ and K-ras- adenomas could be detected for other factors. In conclusion, dietary and lifestyle factors may influence risk of K-ras+ and K-ras- adenomas differently. However, epidemiological literature on diet, lifestyle and colorectal K-ras mutations is inconsistent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / etiology*
  • Adenoma / genetics
  • Adenomatous Polyposis Coli / etiology
  • Adult
  • Aged
  • Case-Control Studies
  • Codon
  • Colorectal Neoplasms / etiology*
  • Colorectal Neoplasms / genetics
  • Feeding Behavior*
  • Female
  • Genes, ras*
  • Humans
  • Life Style*
  • Logistic Models
  • Male
  • Middle Aged
  • Netherlands
  • Odds Ratio
  • Point Mutation*
  • Riboflavin / administration & dosage
  • Risk Assessment
  • Risk Factors
  • Smoking / adverse effects
  • Surveys and Questionnaires


  • Codon
  • Riboflavin