Flow cytometric and histologic evaluation in a large cohort of patients with ulcerative colitis: Correlation with clinical characteristics and impacton surveillance

PURPOSE: To examine the prevalence of DNA aneuploidy as a function of the e xtent of ulcerative colitis and to study the correlation of aneuploidy with clinical characteristics. Furthermore, the occurrence of aneuploidy and dy splasia during colonoscopic surveillance was studied in a subset of these p atients. METHODS: By analyzing 5404 biopsy samples of 368 patients with ulc erative colitis, we have evaluated the importance of DNA ploidy measured by flow cytometry. We have also investigated the influence of extent (219 pat ients with extensive or total colitis vs. 149 patients with localized colit is) and duration of colitis on the development of dysplasia (patients with biopsy specimens that showed inflammation alone were compared with those wi th biopsy specimens that were equivocal or positive for dysplasia) and aneu ploidy. Included was a subgroup of patients with ulcerative colitis and pri mary sclerosing cholangitis (n = 16). RESULTS: Aneuploidy was found in 8.7 percent (392/368) of all patients. The prevalence of aneuploidy increased b y the extent of ulcerative colitis (2 percent localized, 6.8 percent extens ive colitis, 14.9 percent total colitis). The frequency of aneuploidy was h igher in patients with disease duration longer than 10 years (P = 0.007). P atients with ulcerative colitis and primary sclerosing cholangitis were mor e likely to develop aneuploidy (9/16, 56.3 percent vs. 14/120, 11.7 percent ; P < 0.001) and dysplasia(4/16,25 percent vs. 10/120,8.3 percent; P= 0.06) than patients without primary sclerosing cholangitis. CONCLUSION: Because DNA aneuploidy represents an early alteration during neoplastic transformat ion in ulcerative colitis, flow cytometry is a valuable tool in the surveil lance of those patients. Primary sclerosing cholangitis represents an addit ional risk factor for the development of DNA aneuploidy and dysplasia.