Prevalence of adenomas and hyperplastic polyps in mismatch repair mutation carriers among CAPP2 participants: report by the colorectal adenoma/carcinoma prevention programme 2

J Clin Oncol. 2008 Jul 10;26(20):3434-9. doi: 10.1200/JCO.2007.13.2795.


Purpose: To determine the prevalence of adenomatous and hyperplastic polyps in a large cohort of individuals with a germline mutation in a mismatch repair (MMR) gene, the major genetic determinant of hereditary nonpolyposis colorectal cancer (HNPCC). These prevalences have been estimated previously in smaller studies, and the results have been found to be variable.

Patients and methods: Colorectal Adenoma/Carcinoma Prevention Programme 2 trial is a chemoprevention trial in people classified as having HNPCC. The 695 patients with a proven germline MMR mutation and documented screening history before the chemoprevention study were the focus of this study. The number, histology, size, and location of polyps found at the participants' first ever colonoscopy were analyzed in a cross-sectional study.

Results: Seventy-four patients (10.6%) were found to have at least one adenoma at first colonoscopy, whereas 37 (5.3%) had at least one hyperplastic polyp. The frequency of an adenoma at first colonoscopy increased from 5.0% (95% CI, 2.8% to 8.3%) in patients younger than 35 years old to 18.9% (95% CI, 9.4% to 32.0%) in patients age at least 55 years (P = .0001 for trend). No such trend was observed for hyperplastic polyps. No sex differences were found for either type of polyp. A marginal association was found between the co-occurrence of adenomas and hyperplastic polyps. Adenomas tended to be more proximally distributed through the colon, whereas hyperplastic polyps tended to be located in the distal colon.

Conclusion: Adenoma prevalence increases with age among MMR mutation carriers, whereas hyperplastic polyp prevalence is consistent. No sex differences were observed for either type of lesion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / epidemiology
  • Adenoma / genetics*
  • Adenoma / pathology
  • Adenoma / therapy
  • Adult
  • Age Distribution
  • Aged
  • Analysis of Variance
  • Colonic Polyps / epidemiology
  • Colonic Polyps / genetics*
  • Colonic Polyps / pathology
  • Colonic Polyps / therapy
  • Colonoscopy
  • Colorectal Neoplasms / epidemiology
  • Colorectal Neoplasms / genetics*
  • Colorectal Neoplasms / pathology
  • Colorectal Neoplasms / therapy
  • Colorectal Neoplasms, Hereditary Nonpolyposis / epidemiology
  • Colorectal Neoplasms, Hereditary Nonpolyposis / genetics
  • Colorectal Neoplasms, Hereditary Nonpolyposis / pathology
  • Cross-Sectional Studies
  • DNA Mismatch Repair
  • Female
  • Follow-Up Studies
  • Genetic Predisposition to Disease / epidemiology*
  • Germ-Line Mutation*
  • Heterozygote*
  • Humans
  • Male
  • Middle Aged
  • Multicenter Studies as Topic
  • Multivariate Analysis
  • Neoplasm Staging
  • Prevalence
  • Proportional Hazards Models
  • Randomized Controlled Trials as Topic
  • Sex Distribution
  • Survival Analysis