Prevalence and risk factors for colorectal adenomas in patients with ulcerative colitis

Background: Patients with ulcerative colitis (UC) have an increased risk of colorectal cancer. Scarce data regarding the development of adenomas in these patients are available both for normal and colitic mucosa. Objective: The objective of this article is to evaluate the prevalence of adenomatous polyps and associated risk factors in patients with UC. Methods: Patients with UC were identified from the databases of two tertiary referral centers. Medical, endoscopic and histologic reports were reviewed. Results: A total of 403 patients were included (53% male; 33% extensive colitis) and 1065 colonoscopies (median per patient, 2) were recorded and analyzed. Seventy-four adenomas in 47 patients (11.7%) and three cases of colorectal cancer were found during a median follow-up of 6.3 years. The cumulative risk of colorectal adenoma was 4.7%, 16.7%, 23.6% and 34.4% at 10, 20, 30 and 40 years from UC diagnosis, respectively. The cumulative risk of developing metachronous colorectal adenoma was 66.7%, 87.9%, and 90.9% at 5, 10, and 15 years from first adenoma detection. Older age at UC diagnosis and longer disease duration were independent risk factors for colorectal adenoma development. Conclusions: The prevalence of colorectal adenomas among UC patients seems to be higher than previously reported, although lower than in the background population.