Effectiveness and costs of screening colonoscopy

Screening colonoscopy is always indicated when rectosigmoidoscopy reveals an adenoma, since this lesion roughly doubles the patient's risk of contracting colonic cancer. Follow-up should be performed at intervals of about three years after endoscopic removal of all colorectal polyps. Repeated screening examinations are recommended for the following genetic diseases that carry an increased risk of colorectal carcinoma: familial adenomatous polyposis (FAP) and its genetic variant, hereditary non-polyposis colorectal cancer syndrome (HNPCC) and hamartomatous polyposis syndromes (e.g. Peutz-Jeghers). Also in the case of familial "sporadic" carcinoma of the colon, regular screening colonoscopies for first degree relatives are recommended. Although the use of regular screening colonoscopies in patients with a long history of extensive ulcerative colitis is controversial, the recent results support such examinations. While the benefit of screening colonoscopy or sigmoidoscopy of the general population from the age of 50 onward must be affirmed, it should be weighed against the costs involved in such an undertaking. At the present time, the American Cancer Society recommends that from the age of 50 onward, the annual fecal test for occult blood should be supplemented by sigmoidoscopy performed every three to five years.