Colonic Adenoma Surveillance

Abstract

While colonic adenoma is a precursor of colonic adenocarcinoma, patients found to have colonic adenoma would require surveillance colonoscopy at different time intervals depending on the number, histology and size of the lesions. In general, subjects with more than 3 adenomas, adenoma >1 cm or adenoma with villous features or high-grade dysplasia would necessitate an earlier colonoscopy. The presence of other risk factors, particularly family history of colorectal cancer (CRC) and personal history of CRC or inflammatory bowel disease, would also influence the surveillance intervals. Unlike screening for colorectal cancer (CRC), colonoscopy is the only recommended tool for surveillance purpose. The role of other techniques like CT colonography or fecal occult blood tests on surveillance of colonic adenoma remains to be determined. Due to the lack of quality data from randomized trials, the surveillance intervals of different colonic adenomas are largely based on expert opinions or consensus. Although there are many different recommendations issued by various professional societies, it remains to be proven in future studies whether these guidelines could be validated, particularly in Asian populations. There is also a tendency to prolong the surveillance intervals of those with negative baseline screening colonoscopy and low-risk colonic adenomas, which would free more colonoscopy capacity for screening of never screened individuals. With the increasing use of screening colonoscopy and detection of asymptomatic colonic adenoma, the volume and impact of surveillance colonoscopy on existing colonoscopy facilities and resources could not be overlooked.