COLON SURVEILLANCE AFTER COLORECTAL-CANCER SURGERY

PURPOSE: This study was performed to determine cost-effective colonosc opy guidelines for patients with prior colorectal adenocarcinoma. METH OD: A retrospective review was performed of patients who had been trea ted for colorectal adenocarcinoma and later underwent follow-up colono scopy from 1984 to 1994. RESULTS: During this study period, 389 patien ts previously treated for colorectal adenocarcinoma underwent follow-u p colonoscopy. Ail patients had perioperative colon evaluation for oth er neoplasms. Ages ranged from 26 to 89 (mean, 65.8) years, and 46.8 p ercent were female. Recurrent or metachronous cancer or a neoplastic p olyp constituted a positive examination. Results of 389 first follow-u p colonoscopies were compared with 259 second (66.6 percent), 165 thir d (42.4 percent), and 83 fourth (21.3 percent) follow-up examinations. Median interval between all colonoscopies was 13 months. Positive exa mination rates for the first two yearly examinations were 18.3 and 18. 5 percent, respectively. Slightly lower, third-year and fourth-year po sitive examination rates were 16.4 and 14.5 percent, respectively. Fou r-year examinations yielded the following: first year-1 carcinoid, 1 n ew adenocarcinoma, and 100 polyps; second year-1 anastomotic recurrenc e and 68 polyps; third year-55 polyps; and fourth year-1 recurrent can cer and 17 polyps. CONCLUSIONS: These data suggest that 1) annual foll ow-up colonoscopy for two years after colorectal cancer surgery is ben eficial for detecting recurrent and metachronous neoplasms and 2) the interval between subsequent examinations may be increased depending on the result of the most recent examination.