Colorectal cancer. Identifying and screening high-risk patients

Colorectal carcinoma is a major cause of cancer-related morbidity and mortality in the United States. High-risk patients should be appropriately identified and screened. Current recommendations from the American Cancer Society for the average-risk patient include both digital rectal examination and fecal occult blood testing annually beginning at age 40, as well as flexible sigmoidoscopy every 3 to 5 years beginning at age 50 after two normal annual examinations. If any of these tests yield positive results, complete examination of the colon with colonoscopy is indicated. The reliability, sensitivity, and cost-effectiveness of both digital examinations and stool occult blood testing have not been reported to be adequate for screening large populations. A more practical approach may be to omit stool testing and recommend screening with flexible sigmoidoscopy for average-risk patients aged 50 and older. Patients with distal adenomas should undergo colonoscopy and polypectomy as necessary, with follow-up colonoscopy determined by the number of polyps and success in removal.