It may be reasonable to use methods other than colonoscopy when the time comes to rescreen people who had negative results on their first screening colonoscopy, according to a recent study.

People with a negative result on screening colonoscopy are advised to repeat the procedure in 10 years. To compare the cost and effectiveness of this approach with those of other rescreening strategies, researchers developed a microsimulation model to evaluate data from persons aged 50 years and older who had no adenomas or cancer detected on screening colonoscopy (Ann Intern Med. 2012;157[9]:611-620). Ten-year rescreening with colonoscopy was compared with no further screening, annual screening with highly sensitive guaiac fecal occult blood testing (HSFOBT) or fecal occult immunochemical testing (FIT), or computed tomographic colonography (CTC) every 5 years.

Rescreening with any method was found to reduce substantially the risk for colorectal cancer compared with no further screening: A total of 7.7 to 12.6 lifetime cases of colorectal cancer occurred per 1,000 persons with perfect adherence to screening guidelines, compared with 31.3 lifetime cases per 1,000 persons who underwent no further screening. Among every 1,000 persons with imperfect adherence to screening guidelines, 17.7 to 20.9 cases of colorectal cancer occurred. In the two adherence scenarios, the differences in life-years across rescreening strategies were small.

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Compared with the currently recommended strategy of continuing colonoscopy every 10 years after an initial negative examination, rescreening at age 60 years with annual HSFOBT, annual FIT, or CTC every 5 years provided approximately the same benefit in life-years, with fewer complications at a lower cost. This led the researchers to conclude that following a negative colonoscopy result at initial screening, regular follow-up with less-invasive screening tools may provide the same lifesaving benefit with fewer risks for complication and at a lower cost than rescreening with colonoscopy every 10 years.

The authors of an accompanying editorial (pp. 673-674), however, pointed out that the investigators might have reached a different conclusion if they had measured for quality-adjusted life-years. The editorialists noted that colonoscopy and other highly sensitive endoscopic screening methods may be more effective than FOBT in reducing cancer incidence, and that most people would likely pay more to never have colorectal cancer at all than to suffer with the disease and survive.