Ki-ras proto-oncogene mutations in sporadic colorectal adenomas: relationship to histologic and clinical characteristics

Gastroenterology. 2001 Aug;121(2):302-9. doi: 10.1053/gast.2001.26278.


Background & aims: [corrected] The goal of this study was to examine the relationship between Ki-ras mutations in colorectal adenomas and characteristics of both the subject (age, gender, and family/personal history of colonic neoplasia) and the adenoma (multiplicity, size, location, and histologic features).

Methods: Ki-ras mutations were detected by direct sequencing in 738 adenomatous polyps removed at baseline from 639 participants in a nutritional trial of adenoma recurrence.

Results: Ki-ras mutations were detected in 17.2% of the adenomas. Ki-ras mutations were unrelated to gender, family, or personal history of colonic neoplasia, location within the colorectum, or adenoma multiplicity, but were more common in older subjects (P = 0.01 for trend), in larger adenomas (P < 0.0001 for trend), in adenomas with villous histology (odds ratio [OR], 3.2; 95% confidence interval [CI], 2.1-4.9 vs. tubular), and in adenomas with high-grade dysplasia (32.0% vs. 13.6%; OR, 3.0; 95% CI, 1.9-4.6 vs. low-grade dysplasia). Multivariate analysis showed Ki-ras mutations to be independently associated with subject age (P = 0.01 for trend), tubulovillous/villous histology (OR, 2.3; 95% CI, 1.5-3.7), and high-grade dysplasia (OR, 1.9; 95% CI, 1.2-3.1). Adenoma size was not independently related to Ki-ras mutation.

Conclusions: Ki-ras mutations are associated with the histologic features of adenoma progression (villous histology and high-grade dysplasia) rather than with adenoma growth.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenoma / genetics*
  • Adenoma / pathology*
  • Aged
  • Colorectal Neoplasms / epidemiology
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / pathology*
  • DNA Mutational Analysis
  • Female
  • Genes, ras / genetics*
  • Genetic Predisposition to Disease
  • Humans
  • Male
  • Mutation
  • Neoplasm Recurrence, Local
  • Prevalence
  • Proto-Oncogene Mas