Decreased risk of subsequent colonic cancer in patients undergoing polypectomy after barium enema: analysis based on data from the preendoscopic era.

Abstract

Published data from the Mayo Clinic gathered during the preendoscopic era were analyzed to show that the risk of subsequent colonic carcinoma is reduced in patients with benign-appearing polyps that are revealed by radiology who then undergo polypectomy. Data from the Mayo Clinic gathered during a 6-year period before the availability of endoscopy were used to determine the effect on the subsequent risk of colonic carcinoma if the benign-appearing polyps initially revealed by radiology had been removed rather than left in place and followed up by serial barium enemas. Data were from 226 patients with benign-appearing polypoid lesions of the colon that were 1 cm in diameter or larger and had been followed up by periodic barium enemas. The period of radiologic surveillance was 12-229 months (mean, 68 months). Between two and 17 barium enemas (mean, 5.2) were performed on each patient. The clinical follow-up period was 12-242 months (mean, 140 months). Twenty-one adenocarcinomas developed at the site of the index polypoid lesion as found on follow-up barium enema examinations of these patients. Eleven additional adenocarcinomas of the colon were found at sites remote from that of the index lesion. If the index polyp had been removed when initially diagnosed radiologically, 66% fewer subsequent carcinomas would have occurred in these patients during the average of 11 years of clinical follow-up. Excision of benign-appearing polyps found on initial barium enema examinations would result in a significant decrease in the subsequent risk of colonic adenocarcinoma.