Colorectal cancer screening: a guide to the guidelines.

The best known guidelines for colorectal cancer screening in the United States are those of the US Multisociety Task Force on Colorectal Cancer, the American Cancer Society, the United States Preventive Services Task Force, the American College of Gastroenterology, and the American Society of Gastrointestinal Endoscopy. Screening is currently endorsed for both average-risk and high-risk persons by all guideline groups. Some guidelines offer a menu of options for average-risk persons, from which patients and physicians can select according to their perceptions and values regarding effectiveness, risk, and upfront costs. The alternative approach of colonoscopy as the preferred strategy simplifies discussions with patients and better reflects current trends in procedure use in the United States. For patients who refuse invasive testing, fecal occult blood testing is available. Quantitative fecal immunochemical tests offer promise for improved performance compared with guaiac testing. Radiographic screening has declined, although double contrast barium enema still remains an option in some guidelines. Computed tomographic colonography remains under active consideration but is not yet endorsed by any of the guidelines. High risk is still based primarily on family history, and the guidelines are fairly consistent in adjusting screening modality and intervals according to family history.