Follow-up of patients with colonic polyps containing severe atypia and invasive carcinoma. Compliance, recurrence, and survival.

Between January 1975 and December 1984 1769 polyps were endoscopically removed from 1219 patients. Eight percent of these patients had polyps containing severe atypia and 5.0% had polyps containing invasive cancer. A close postoperative surveillance program was followed by only a few patients, but compliance improved with longer follow-up intervals. Metachronous polyps were observed with similar frequency in patients with benign polyps (34.8%) and those with polyps containing severe atypia (23.8%) or cancer (41.7%). Patients in whom malignant polyps were endoscopically removed had a 5-year survival rate of 84.3% that did not differ from that of patients' whose polyps contained severe atypia (79.0%). It was concluded that endoscopic removal of malignant polyps with favorable histologic conditions does not impair survival. The follow-up program of these patients should be adapted to that of patients with benign polyps, a procedure that may even improve patient compliance.