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Rationale for aggressive colonoscopy in patients with colorectal neoplasia.

The role of colonoscopy in patients with colorectal neoplasia is not well established. The results of colonoscopy, from 1982 through 1987, in 42 patients with cancers who underwent preoperative colonoscopy (group 1), 64 patients with benign polyps (group 2), and 51 patients who were examined only postoperatively (group 3) were reviewed. These results indicated that (1) approximately one third of all findings would have been missed if endoscopy had been performed to only 60 cm; (2) there was a high incidence of synchronous lesions (33.3%) in group 1 and 34.4% in group 2); (3) 57% of patients with synchronous cancer and 63.6% of patients with synchronous polyps developed metachronous lesions, compared with 10.7% and 11.9% of patients with a single lesion; (4) there was a higher incidence of metachronous lesions seen in group 3, compared with group 1; and (5) the median interval for noting metachronous lesions in patients who underwent colonoscopy preoperatively was approximately 18 months. These findings endorsed preoperative colonoscopy and aggressive follow-up in patients with colorectal tumors.