Cancer and dysplasia in ulcerative colitis: a histologic study of 301 surgical specimen.

Patients with ulcerative colitis (UC) have an increased risk to develop colorectal cancer, and epithelial dysplasia is its common precursor lesion. Herein, we present the first study on the relationship of dysplasia and cancer in UC which is based on a systematic histologic screening policy applied to a series of surgical specimen obtained from 301 patients. Cancer was found in 20 patients (prevalence: 7%), and dysplasia without cancer was found in additional 12 patients (prevalence: 4%). All 32 UC patients with cancer or dysplasia without cancer featured at least one high-risk factor for cancer in UC. The median age of UC-cancer patients was 45 years, while the median age of UC-dysplasia patients was 38 years. In all UC-cancer patients evaluable but one (94%), cancer was associated with low- or high-grade dysplasia at the cancer margin. In addition, 71% of UC-cancer patients evaluable had dysplasia at multiple sites. As a consequence, multiple cancers were found in 6 of 20 patients (30%). All multiple cancers occurred in the younger patients, none in the older (p < 0.05). In patients without cancer, however, dysplasia was limited to one site in the colon or rectum in the majority of cases (55%). Dysplasia occurred at any site along the colon and rectum, including the anal transition zone, but no consistent pattern of dysplasia sites was found. No dysplasia was found in the rectum of 35% of patients with UC-cancer, and in 45% of patients with dysplasia without cancer, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)