Colitis‐associated DNA aneuploidy and dysplasia in Crohn's disease and risk of colorectal cancer

Background: There is uncertainty about how patients with Crohn's colitis should be monitored for colorectal cancer (CRC). By analogy to ulcerative colitis, regular colonoscopy with biopsies for dysplasia has been used. We describe the occurrence of dysplasia and DNA aneuploidy in a cohort of patients with Crohn's colitis. Methods: In all, 245 patients with extensive colitis (225 with a firm diagnosis of Crohn's disease, and 20 diagnosed as indeterminate colitis) at Stockholm Soder Hospital and Karolinska University Hospital, Huddinge were included. They were followed with regular colonoscopies with biopsies both for dysplasia and DNA aneuploidy. The cumulative occurrence of DNA aneuploidy and dysplasia was estimated using Kaplan–Meier curves. Time sequences and interactions between DNA aneuploidy, dysplasia, and CRC were studied using Cox regression analysis, adjusted for age, sex, and age at diagnosis. Results: During a median follow-up time of 9.2 person-years, DNA aneuploidy was found in 53 patients (22%), with 10 patients having multifocal aneuploidy and high S-phase values. Dysplasia was found in 42 patients (17%), 10 having multifocal dysplasia. Relative risk (RR) of dysplasia given DNA aneuploidy was 5.3 (95% confidence interval [CI] 2.3–12). RR of CRC given dysplasia was 10 (95% CI 2–50), and RR of CRC given aneuploidy was 1.5 (95% CI 0.3–9.3). Conclusions: Dysplasia and DNA aneuploidy including S-phase analysis may complement stratification of patients with Crohn's colitis with respect to risk of CRC and thus the need for surveillance. (Inflamm Bowel Dis 2010)