Fecal occult blood testing for colorectal cancer: a perspective.

Colorectal cancer is an important health problem in western countries. Early detection of colorectal cancer reduces mortality. The best evidence for the effectiveness of screening for colorectal cancer is with annual or biennial fecal occult blood testing. While the benefit of fecal occult blood testing is small in absolute terms, the incremental cost-effectiveness of this screening strategy appears acceptable. Combining fecal occult blood testing with periodic flexible sigmoidoscopy or replacing it altogether with infrequent colonoscopy are theoretically attractive screening strategies, but the incremental costs and effectiveness of these more intensive screening strategies have not been well defined. Whether and how to implement population-based screening for colorectal cancer depends largely on available resources.