Carcinoma of the colon complicating chronic ulcerative colitis.

Summary Twelve cases of carcinoma of the large bowel among 316 cases of ulcerative colitis seen at the Clinic since 1945 have been reported, an incidence of 3.8 per cent. This indicates an increased tendency on the part of the colonic mucosa to undergo malignant degeneration in ulcerative colitis. Carcinoma of the colon may appear earlier in patients with ulcerative colitis than in the general population. The average age of onset of the neoplasm in this series was 44.3 years. Carcinoma usually appears only after ulcerative colitis has been present for a period of years; the average duration of colitis in this series was sixteen years before malignant degeneration. The symptoms caused by the development of carcinoma may be indistinguishable from symptoms usually caused by an exacerbation of the colitis. Pseudopolyposis may be a predisposing factor in the development of carcinoma, and was present in 5 of the 12 cases reported, or 43 per cent. Colectomy should be considered in the ulcerative colitis patient who has developed adenomatous polyps. Short-circuiting operations such as ileostomy and cecostomy offer no assurance that carcinoma will be prevented. Four of our 12 cases had such operations years before the development of malignancy. While no patient with ulcerative colitis should be made anxious by overemphasizing the increased tendency to malignant degeneration, nevertheless regular follow-up examinations such as proctoscopy and barium enema examinations should be required in every established case regardless of the duration of any remission in symptoms. In this way only will carcinoma be detected in the earliest possible stage. We believe that when ileostomy is necessary, colectomy should be seriously considered for the patient with ulcerative colitis.