Content area
Full Text
Related Article: Editorial, N Engl J Med 2008 :359 ;1285 -1287 .
Colonoscopy has gained widespread acceptance and even some preference as the primary screening method for the detection of colorectal cancer and precancerous polyps.1 -4 There is concern about whether adequate resources exist to satisfy the demand for colonoscopy,5 -7 and some data suggest that colonoscopy may be performed too frequently and for inappropriate indications.8 ,9 Determination of the appropriate frequency of rescreening for persons with normal findings on initial screening colonoscopy could have a substantial effect on the cost of colonoscopy and the capacity to provide it.
Guidelines for colorectal cancer screening from the U.S. Multisociety Task Force on Colorectal Cancer and the American Cancer Society include, among other strategies, sigmoidoscopy every 5 years and colonoscopy every 10 years.3 ,4 The U.S. Preventive Services Task Force also recommends colonoscopy as a screening test but does not specify a test interval.1 Evidence supporting the 10-year interval comes largely from case-control studies that suggest that screening by sigmoidoscopy reduces mortality from distal colorectal cancer for up to 10 years.10 ,11 However, there are no direct data with which to assess the validity of this recommendation. To provide direct data that can be used to inform decision making about an appropriate rescreening interval, we determined the incidence of any neoplasia and of advanced neoplasia on 5-year rescreening colonoscopy among persons who had no neoplasia on baseline screening colonoscopy.
Methods
Study Design
This study consisted of a retrospective examination of data obtained as part of routine clinical care of persons in the Lilly Colorectal Cancer Prevention Program; identifying information was removed from all data. A total of 36 gastroenterologists and gastrointestinal surgeons at seven sites in central Indiana participate in the program. The protocol was approved by the institutional review board of Indiana University. In September 1995, Eli Lilly began providing screening colonoscopy as a health benefit for employees, retirees, and dependents 40 years of age or older who had no personal history of colorectal cancer, adenomatous polyps, or inflammatory bowel disease and who were asymptomatic (i.e., reported no recent visible rectal bleeding, no change in bowel habits, and no recent or current lower abdominal pain). Until October 2004, it was the program's policy to rescreen persons...