Incidence and recurrence rates of colorectal adenomas in first-degree asymptomatic relatives of patients with colon cancer

OBJECTIVES: Subjects with one first-degree relative affected with colorecta l cancer are considered to be at increased risk of colorectal adenomas. We compared the recurrence and incidence rates of colorectal adenomas among su bjects with one first-degree relative with colorectal cancer and those with out family history. METHODS: A series of consecutive asymptomatic subjects successfully underwe nt a colonoscopy, were found to have either normal results or at least one adenoma, provided a detailed family history, and were offered a second colo noscopy 3 yr later; 190 out of 436 subjects accepted, 134/172 with one or m ore adenomas and 56/264 with no abnormalities at the initial examination. A first-degree family history was reported by 43/134 and 26/56, respectively . RESULTS: By multivariate analysis, the presence of adenomas at follow-up ex amination was significantly associated with a positive family history of co lorectal cancer in both subgroups, those with a previously resected adenoma (odds ratio = 2.23, 95% CI = 1.04-4.79) and those without (odds ratio = 8. 95, CI = 1.29-62.22). CONCLUSION: A history of one first-degree relative with colorectal cancer i s associated with a significant increase in 3-yr cumulative incidence and r ecurrence rates of adenomas. (C) 2001 by Am. Cell. of Gastroenterology.