Summary The New England Journal of Medicine published the results

of the National polyp surveillance (NPS) study in reference to colon cancer mortality among patients with colonic adenomas [1]. This is a prospective study of 2,602 patients who were enrolled from 1980 to 1990 to undergo colonoscopy and fol-lowed up for a median time of 15.8 years, with a maximum of 23 years. Only higher-risk patients were enrolled (positive findings on barium enema or sigmoidoscopy, positive fecal occult blood test, patients with symptoms, positive family history for colon cancer), all polyps were removed and this study was performed in centers of excellence. Among patients in whom adenomas were removed, 12 deaths from colon cancer occurred in this follow-up period whereas 25.4 deaths were expected in the carefully matched controls of the general population. Previously, these authors had demonstrated that the removal of adenomatous polyps reduced the expecte