[Cancer prevention with the endoscope. Search not only for polyps!].

Through the rigorous application of polypectomy, the colon carcinoma rate can be clearly reduced (66%). The term "polyp" comprises epithelial (hyperplastic or neoplastic) and nonepithelial causes. The majority of carcinomas in the colon develop from adenomatous tissue (adenoma-carcinoma sequence). Pedunculated adenomas (90% of all polyps) are removed with the high-frequency diathermy snare. In some cases, flat (sessile) polyps can be elevated by injections placed below them, and then removed with the diathermy snare (strip biopsy). In the event of larger or large-area flat polyps that cannot be removed with the snare, piecemeal resection is applied. The excision alone of adenomas with a stage I carcinoma is carried out only in so-called low-risk situations. Flat neoplasms make particular demands of the endoscopist, since they often appear merely as a reddish area, but may already have invaded the submucosa when diagnosed. For classification and, where indicated, endoscopic resection, the recommendations of the Japanese Society of Gastroenterological Endoscopy are applied.