Prevalence of adenomas among young individuals at average risk for colorectal cancer

Am J Gastroenterol. 2005 Jan;100(1):139-43. doi: 10.1111/j.1572-0241.2005.41000.x.


Objectives: We evaluated the prevalence and characteristics of adenomas in a young population not genetically predisposed for the development of colorectal cancer (CRC).

Methods: The databases of the Dutch Hereditary Colorectal Cancer Registry were used. The study population included patients (n = 444) who had regular endoscopy until mutation analysis revealed they did not carry the (Adenomatous Polyposis Coli (APC)/Mismatch Repair) gene defect identified in their family.

Results: At first colonoscopy (n = 342; 50% males, mean age 37 yr) a total of 19 adenomas (10 males, mean age 50 yr, range 24-91 yr) and two CRCs (2 males, age 49 and 72 yr) were identified, and at first sigmoidoscopy (n = 102; 53% males, mean age 29 yr) three adenomas (2 males, age 8, 40, and 41 yr) were found. A second colonoscopy was performed in 14 patients with, and in 162 patients without an adenoma. Three of 14 patients (21%) developed a new adenoma (all >50 yr) and 8 of 162 (5%) patients developed their first adenoma during follow-up. In the colonoscopy group, the cumulative proportion of patients free of adenomas at age 50 yr was 86%. Of all adenomas diagnosed during colonoscopy (n = 49), 65% were located distal from the flexura lienalis. Of the adenomas detected during all endoscopies (n = 53), 9.8% were > or =7 mm, 7.5% showed high-grade dysplasia, and 7.5% showed tubulovillous features.

Conclusions: On the basis of our findings during colonoscopy we conclude that the risk of developing adenomas/CRC in young individuals without genetic risk factors is low. Adenoma surveillance programs should focus on young individuals with a positive family (or personal) history for adenomas/CRC, or on individuals >50 yr.

MeSH terms

  • Adenoma / epidemiology*
  • Adenoma / etiology
  • Adenoma / pathology
  • Adolescent
  • Adult
  • Age Distribution
  • Child
  • Colonoscopy
  • Colorectal Neoplasms / epidemiology*
  • Colorectal Neoplasms / etiology
  • Colorectal Neoplasms / pathology
  • Female
  • Genetic Predisposition to Disease
  • Humans
  • Male
  • Middle Aged
  • Netherlands / epidemiology
  • Prevalence
  • Risk Assessment
  • Sex Distribution