Current colorectal cancer screening strategies: overview and obstacles to implementation.

Colorectal cancer is the second leading cause of cancer death but is largely preventable. Current strategies to prevent colorectal cancer vary considerably with regard to effectiveness, up-front costs, risks, and invasiveness. Current levels of participation in colorectal cancer screening in the U.S. population are low. Both physician and patient attitudes contribute to low levels of screening uptake. New colorectal cancer tests are one mechanism to improve adherence. Virtual colonoscopy may have an important impact if techniques to perform it without bowel preparation can be developed. Stool-based DNA testing is likely to be the most effective entirely noninvasive strategy and will be easier for patients to perform than fecal occult blood testing. The potential for improvements in the technology are substantial, and data from second-generation assays have already been reported. The cost-effectiveness of new strategies needs further evaluation.