Failure of colonoscopic surveillance in ulcerative colitis.
A prospective surveillance programme for patients with longstanding (> = 8 years), extensive (> = splenic flexure) ulcerative colitis was undertaken between 1978 and 1990. It comprised annual colonoscopy with pancolonic biopsy. One hundred and sixty patients were entered into the programme and had 739 colonoscopies (4.6 colonoscopies per patient; 709 patient years follow up). Eight eight per cent of examinations reached the right colon. There was no procedure related death. One Dukes's A cancer was detected. Forty one patients (25%) defaulted. Of these 25 remain well; 13 are unaccounted for, and one died from colonic cancer. One patient had colectomy for medical reasons, and another died of carcinoma of the pancreas. Retrospectively an additional 16 eligible patients were identified who had not been recruited. Of these, 14 remain well, two are unaccounted for. None developed colonic cancer. Four patients refused colonoscopy. All remain well. Over the same period seven other cases of colonic cancer were found in association with ulcerative colitis, two in patients who had erroneously been diagnosed as having only proctitis and were therefore not entered into the programme, but were found at operation to have total colitis, one in a patient with colitis of seven years duration, and four patients who had previously attended the clinic but had been lost to follow up before 1978 and then had represented with new symptoms during the surveillance period. Thus, of the nine colitis related cancers diagnosed in this centre during the study period only one was detected by the surveillance programme. The results of this large study, a a review of published works, cast doubts on the effectiveness of colonoscopic surveillance programmes in detecting colorectal cancer in patients with ulcerative colitis.