Cancer surveillance in ulcerative colitis-a time for reappraisal

Cancer surveillance in ulcerative colitis-a time for reappraisal Patients who have had an attack of universal or extensive ulcerative colitis have a greater likelihood of developing colonic cancer than the normal population."6 The enhanced risk begins about 10 years after the initial attack. Earlier reports exaggerated the danger of malignant change because they were based upon retrospective studies of patients who had been referred to specialised centres.' 2 7 Recent population based studies suggest that the risk is considerably less.' 8 9 The recognition that ulcerative colitis has a malignant potential places a responsibility on clinicians to minimise or eliminate the risk that these patients will die from colonic cancer. One solution advocated is to perform colectomy 10 years after the initial attack.'0 This would virtually eliminate the possibility of cancer but most gastroenterologists and patients prefer a less radical approach, that of 'surveillance'. " I The finding that in many cases, cancer could be predicted by the finding of dysplas-tic change in the rectal mucosa12-14 has led to the view that the best method of surveillance must be regular colonoscopy, which permits the whole colon to be visualised, with target biopsy where appropriate. In addition a wide area of mucosa can be sampled for dysplastic change. It seems logical that patients who have had extensive or total ulcerative colitis should have regular annual colonoscopy starting eight to 10 years after the first attack of ulcerative colitis. If this is undertaken rigorously it is argued the risk of cancer will be minimised and when present, neoplastic lesions will be detected'at an early stage and mortality from colorectal cancer will be greatly reduced. Over the past 12 years several large prospective studies have assessed this policy of colonoscopic surveillance. Most have concluded that it is the best way of managing this difficult problem but when these studies are critically analysed the case for colonoscopic surveillance is weaker than at first sight, and some commentators consider that the exercise is not cost effective and that when assessed on an 'intention to survey' basis they confer little benefit. 15-20 Twelve studies of colonoscopic cancer surveillance in ulcerative colitis have been published in sufficient detail to analyse critically.203l The stated intention in most of them was to undertake colonoscopic surveillance in all patients who had had total or extensive disease. Surveillance was usually started eight to 10 years after the initial attack. A total …