Colonoscopic detection of early colorectal cancers. Impact of a surgical endoscopy service.

Abstract

The Surgical Endoscopy Service has been aggressively evaluating gastrointestinal symptoms with colonoscopy and screening asymptomatic patients with flexible sigmoidoscopy in hopes of finding early curable colorectal cancers. The purpose of this study was to compare the stages of colorectal cancers resected during the 18-month period prior to (Pre-SES) and during the first 18 months (Post-SES) after the creation of the Surgical Endoscopy Service. In addition, the yield of lesions that would have been obtained by depending upon patient symptoms or occult blood testing were determined. A total of 361 colonoscopies were performed Pre-SES and 874 colonoscopies Post-SES; 26 patients underwent resection of colorectal cancers Pre-SES and 32 Post-SES. Whereas early colorectal cancers (Dukes' A and B1) were found in only three patients (12%) Pre-SES period, early cancers were found in 13 (41%) Post-SES. Doubling the number of colonoscopies produced a fourfold increase in the number of early lesions. Furthermore, disseminated cancers (D lesions) dropped from 19% Pre-SES to 3% Post-SES. Among the total 58 patients, 43% of the A lesions and 40% of the B1 lesions were asymptomatic. Even more alarming, 86% of the A lesions, 50% of the B1 lesions, 31% of the B2 lesions, and 14% of the C2 lesions were occult blood negative. Indeed, only the D lesions were uniformly occult blood positive. This study demonstrates that aggressive colonoscopy detects early colorectal cancers. Moreover, patient symptoms or occult blood testing will fail to indicate the majority of early colorectal cancers.