Screening for colorectal cancer: sample techniques.

Colorectal cancer is a major health problem. Despite therapeutic advances, the overall five-year survival rate remains at 45%. At the present time the greatest potential for improved survival lies with early detection. The authors of this article have assessed a number of colorectal surveillance programs in an attempt to identify those individuals with potentially pre-malignant disease or early localized cancer. Differences in individual risks and the availability of numerous "screening tests" make it important to provide each patient with the most appropriate investigation. Preliminary evidence suggests that fecal occult blood tests, sigmoidoscopy, and colonoscopy with polypectomy can be effective in reducing the incidence of colon cancer.