Study Selection: When available, the most recent high-quality systematic review was used to identify relevant articles. This review was then supplemented with a MEDLINE search for more recent articles.Data Extraction: One reviewer abstracted information from the final set of studies into evidence tables, and a second reviewer checked the tables for accuracy. Discrepancies were resolved by consensus.Data Synthesis: For average-risk adults older than 50 years of age, evidence from multiple well-conducted randomized trials supported the effectiveness of fecal occult blood testing in reducing colorectal cancer incidence and mortality rates compared with no screening. Data from well-conducted case-control studies supported the effectiveness of sigmoidoscopy and possibly colonoscopy in reducing colon cancer incidence and mortality rates. A nonrandomized, controlled trial examining colorectal cancer mortality rates and randomized trials examining diagnostic yield supported the use of fecal occult blood testing plus sigmoidoscopy. The effectiveness of barium enema is unclear. Data are insufficient to support a definitive determination of the most effective screening strategy.Conclusions: Colorectal cancer screening reduces death from colorectal cancer and can decrease the incidence of disease through removal of adenomatous polyps. Several available screening options seem to be effective, but the single best screening approach cannot be determined because data are insufficient. T he U.S. Preventive Services Task Force (USPSTF) last considered its recommendations regarding colorectal cancer screening in 1996 (1). At that time, the available evidence included one randomized, controlled trial showing that fecal occult blood testing (FOBT) reduced mortality rates (2); a case-control study showing that persons having sigmoidoscopy were less likely to die of colorectal cancer (3); and one nonrandomized, controlled trial of FOBT combined with rigid sigmoidoscopy that suggested some benefit from the two tests together (4). On the basis of this evidence, the USPSTF recommended screening for colorectal cancer with FOBT, sigmoidoscopy, or both (a grade B recommendation) but did not recommend for or against other means of screening (digital rectal examination, double-contrast barium enema, or colonoscopy) because the available evidence was insufficient. (See the companion article in this issue for a description of the USPSTF classification of recommendations.) The Task Force also recommended that FOBT be performed yearly but did not specify an interval for sigmoidoscopy.Since 1996, important new evidence has emerged regarding the effectiveness of colorectal cancer screening. We performed an updated systematic review to help the USP-STF evaluate new evidence on the effectiveness of different colorectal cancer screening tests as it updated its previous recommendation. We examined the evidence concerning the effectiveness of screening in adults older than 50 years of age who are at average risk for colorectal cancer. The effectiveness,...

The Evaluation of Genomic Applications in Practice and Prevention (EGAPP) Initiative, established by the National Office of Public Health Genomics at the Centers for Disease Control and Prevention, supports the development and implementation of a rigorous, evidence-based process for evaluating genetic tests and other genomic applications for clinical and public health practice in the United States. An independent, non-federal EGAPP Working Group (EWG), a multidisciplinary expert panel selects topics, oversees the systematic review of evidence, and makes recommendations based on that evidence. This article describes the EGAPP processes and details the specific methods and approaches used by the EWG.

CRC is a common disease responsible for an estimated 52,000 deaths in the United States in 2007. In about 3% of newly diagnosed CRC, the underlying cause is a mutation in a MMR gene (Lynch syndrome) that can be reliably identified with existing laboratory tests. Relatives inheriting the mutation have a high (about 45% by age 70) risk of developing CRC. Evidence suggests these relatives will often accept testing and increased surveillance.

Chair, on behalf of the EGAPP Working Group The Evaluation of Genomic Applications in Practice and Prevention (EGAPP) Initiative, established by the National Office of Public Health Genomics at the Centers for Disease Control and Prevention, supports the development and implementation of a rigorous, evidence-based process for evaluating genetic tests and other genomic applications for clinical and public health practice in the United States. An independent, non-federal EGAPP Working Group (EWG), a multidisciplinary expert panel selects topics, oversees the systematic review of evidence, and makes recommendations based on that evidence. This article describes the EGAPP processes and details the specific methods and approaches used by the EWG.