Colorectal cancer is the third most commonly diagnosed cancer and the second leading cause of cancer death in the United States. In 1996, an estimated 133,500 new cases of colorectal cancer were diagnosed, and approximately 54,900 people died of the disease. Colorectal cancer survival is closely related to the clinical and pathological stage of the disease at diagnosis. Approximately 65 percent of patients present with advanced disease. Five-year survival for cancer limited to the bowel wall at the time of diagnosis approaches 90 percent, while survival at 5 years is less than 10 percent with metastatic disease.

Evidence exists that reductions in colorectal cancer morbidity and mortality can be achieved through detection and treatment of early-stage colorectal cancers and the identification and removal of adenomatous polyps, the precursors of colorectal cancer. Colorectal cancer screening tests have been shown to achieve accurate detection of adenomatous polyps and early-stage cancer. However, there is a lack of consensus concerning the choice of screening and surveillance tests and appropriate screening and surveillance intervals. The Agency for Health Care Policy and Research (AHCPR) arranged for the development of this technical review to summarize current scientific evidence on colorectal cancer screening and highlight areas for future research to improve screening. This is the first in a series of technical reviews and evidence reports to be published by AHCPR under the Agency's Evidence-Based Practice Initiative.

This technical review is based on a systematic review of the scientific literature. It provides a review of screening for colorectal cancer and adenomatous polyps in asymptomatic persons at average risk for colorectal cancer, subsequent diagnostic evaluation in those with positive screening tests, and surveillance of those with colorectal disease.