Statement from the American Gastroenterological Association on colonoscopy surveillance study


Study published in Annals of Internal Medicine

Colorectal cancer (CRC) is the second-leading cause of cancer death in the United States. Most cases of CRC originate in a polyp; therefore finding and removing colon polyps can prevent CRC. Colon cancer screening is the search for polyps and cancer in asymptomatic people. Colonoscopy, flexible sigmoidoscopy, barium enema and fecal occult blood testing are tests that can be utilized in colorectal cancer screening. Colonoscopy is the most sensitive test for detecting polyps and the only procedure that allows both detection and removal of the polyp simultaneously.

Colonic surveillance, as opposed to screening, is the periodic examination of the colon after polyps and/or cancer has been identified. It is currently estimated that less than 30 percent of the American population age 50 and older has been screened for CRC. It's essential to note that the recent study by Mysliwiec1 in the Annals of Internal Medicine does not suggest that there are too many initial screening colonoscopies being performed at present.

Rather, the study suggests that too many surveillance colonoscopies are performed. The American Gastroenterological Association disputes the validity of this conclusion.

The Annals study is based on physician's self-reporting practice patterns based on hypothetical cases. Because this study does not contain clinical detail, physicians may over or underestimate their own clinical behavior. Many guidelines currently exist for colon polyp surveillance. The appropriate time interval for surveillance is influenced by many factors (type of polyp, size, number and the adequacy of the colonic prep).

An important issue raised in the study is what is the clinical significance of the small polyp? The guidelines proposed by the AGA and a consortium of GI societies could not provide recommendations for their surveillance due to the lack of scientific studies to define the appropriate behavior. Therefore, it is wrong to judge inappropriate the actions of physicians who performed surveillance colonoscopies on patients with small polyps.

The National Cancer Institute, which funded this study, should take the logical next step and fund a long-term study of the natural history of the small polyp. Applying the knowledge generated by such a study could positively impact the very real public health issues of the cost of colorectal cancer surveillance and clinical care strategies for small polyps.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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