Long term risk of clinically manifest colorectal cancer among patients with negative findings at colonoscopy

Screening colonoscopy is thought to be a powerful and cost-effective tool to reduce colorectal cancer incidence and mortality. In the absence of long-term follow-up data, repeat colonoscopy after 10 years has commonly been recommended after a negative colonoscopy in the past. A recent case-control study from Germany (380 case, 485 controls) found that patients with negative findings at colonoscopy are at very low risk of colorectal cancer and might not need to undergo repeat colonoscopy for 20 years or more, if at all (Brenner et al. Does a negative screening colonoscopy ever need to be repeated ? Gut 2006;55:1145-1150). These findings suggest the possibility to extend screening intervals to 20 years or more, which might reduce complications, and increase feasibility and cost-effectiveness of colonoscopy based screening programs.

Hermann Brenner

Division of Clinical Epidemiology and Aging Research, German Cancer Research Centre, Heidelberg, Germany