This report reviews the state of the art in cancer prevention by endoscopic polypectomy of familial adenomatous polyposis (FAP). FAP is a hereditary disease characterized by the development of multiple adenomatous polyps in the gastrointestinal tract. The timing of colectomy depends on the size and number of adenomatous polyps. This trial evaluates the usefulness and safety of thorough endoscopic polypectomy in patients with FAP. The main endpoint is whether or not a patient needs surgery on the large intestine during the intervention period. Colorectal polyps will be thoroughly removed by periodic colonoscopy. Patients who have (or had) 100 or more adenomas in the large intestine and who refused to undergo surgery despite of being advised to do so, and who are 16 years or older. Intervention period is 5 years.
