Colonoscopy Screening at Intervals Longer Than 10 Years Is Feasible

Case-control studies and cohort studies have found that colonoscopy prevents colorectal cancer (CRC) for 15 to 20 years or more. However, only a few small studies have reported the yield of a second screening colonoscopy performed 10 years after an initial negative examination.

In this report from the German screening colonoscopy program, 120,298 repeat screening colonoscopies in patients aged 65 years or older were compared with all 1.25 million screening colonoscopies performed on patients at age 65 or later in the same time frame. Of the repeat screenings, 49% were performed at 10 years, 29% at 11 years, 12% at 12 years, and the remainder at 13 to 16 years.

The adenoma detection rate was 10% to 12% lower at repeat colonoscopy. The absolute risk of advanced neoplasm at repeat colonoscopy was higher in men than women and in persons older than age 75 years. For men, the risk of CRC was 76% to 85% lower for repeat colonoscopy than for all examinations, regardless of the interval. For women, the CRC risk was 75% to 78% lower in the repeat examinations at 10 years and 63% to 74% lower for those with intervals >10 years. The risk of any advanced neoplasm across different age and gender groups and interval lengths was reduced by about 40% to 60% with repeat screenings compared with first screenings.