Colorectal Cancer and Surveillance in Patients with Ulcerative Colitis: the Japanese Study

Abstract

We reviewed published reports on colorectal carcinoma complicating ulcerative colitis (UC) in Japan. Among the total of 312 patients who developed carcinoma associated with UC, 73% were at 10 years or more after the initial attack and 83 % had total colonic involvement. The proportion of patients in whom cancers were multifocal, infiltrating, and poorly differentiated was 29 %, 44 %, and 45 %, respectively. Carcinoma was detected at a significantly earlier stage in the surveillance group than the non-surveillance group who under-went ordinary clinical care only (P < 0.005). Among 'the patients initially diagnosed as having low-grade dys-plasia in the surveillance group, 77% (10/13) developed early cancer on follow-up, compared with 50% (3/6) in high-grade dysplasia, and 21% (3/14) in carcinoma (P<0.05). These results suggest that colonoscopic sur-veillance can be an useful aid in allowing the detection of carcinoma at an early stage. However, an addi-tional marker of detecting individuals at high risk for the development of colorectal cancer seems necessary to reduce the high percentage of the patients with Dukes' grade C or worse even in the surveillance group.