Utility of endoscopic follow-up after resection of colorectal cancer

Objective: Patients resected for colorectal cancer are at increased risk for an anastomotic recurrence, for adenomatous polyps and for a metachronous cancer. A regular colonoscopic surveillance in these patients is justified for early detection and potential resection of anastomotic recurrences, new primary cancer and adenomatous polyps.

Methods: 322 patients were observed and resected for colorectal cancer between 1970 and 1988, with complete staging agreed to be included in a follow-up program (median follow-up: 105 months). To December 1993 all the patients were submitted to colonoscopy once yearly for the first 5 years and then every 2 years.

Results: Anastomotic recurrence was observed in 22 of the 253 patients who underwent resection for rectal or sigmoid adenocarcinoma (8.7%). Sixteen of these patients were submitted to a second curative resection with a median survival of 35 months; the median survival was 6 months in the 6 patients who could not undergo this operation (p = 0.0018). Metachronous adenomas of the residual colon were found in 24 patients (7.4%) and metachronous cancers in 5 (1.5%) at Stage A, according to Dukes' classification.

Conclusions: In patients resected for rectal or sigmoid carcinoma, a sigmoidoscopy should be performed every 6 months for the first 2 years for the early detection of anastomotic recurrences. In all cases, a colonoscopy should be performed every 5 years after surgery to detect metachronous lesions at early stage. Before surgery, a "clean colon" should always be established to detect possible synchronous lesions.