Abstract IA007: Time to extend screening colonoscopy intervals? If so, by how much and for whom? Findings at 120,000 repeat screening colonoscopies conducted 10 or more years after a negative screening colonoscopy

Abstract

Abstract Background: Screening colonoscopy effectively reduces colorectal cancer (CRC) incidence and mortality by enabling detection and removal of precancerous lesions. However, evidence for the optimal interval for colonoscopic screening is limited, making this a subject of debate. A systematic review and meta-analysis of 28 studies published in 2019 found that detection of advanced neoplasms (ADN) within 10 years after a negative index colonoscopy is rare.1 This suggests that 10 year intervals for screening colonoscopy, as currently recommended,2 may be adequate. However, evidence for defining screening colonoscopy intervals beyond ten years has remained very sparse. We aimed to assess the prevalence of advanced colorectal neoplasms (ADN) at least ten years after a negative screening colonoscopy in a very large cohort of repeat screening colonoscopy participants in Germany. Methods: We derived sex- and age-specific ADN prevalences based on 120,298 repeat screening colonoscopies (women, 60.1%) conducted at ages 65+ at least 10 years since previous negative colonoscopy and reported to the German screening colonoscopy registry in 2013-2019. The findings were compared to all screening colonoscopies conducted at ages 65+ in the same period (1.25 million) by calculating standardized prevalence ratios (SPRs). Results: ADN prevalences were 3.6% and 5.2% among women and men 10 years after a negative screening colonoscopy and gradually increased to 4.9% and 6.6%, respectively, ≥14 years after a negative colonoscopy, compared to 7.1 and 11.6%, respectively, among all screening colonoscopies conducted during the same time period. Prevalences increased with age in all groups, but were consistently much lower in repeat colonoscopies conducted 10 or more years after a negative colonoscopy than among all colonoscopies within each subgroup defined by sex and age (SPRs for CRC: 0.22-0.38 among women and 0.15-0.24 among men, respectively; SPRs for ADN: 0.49-0.62 among women and 0.50-0.56 among men, respectively). Conclusions: ADN prevalences at colonoscopies conducted 10 years after a negative screening colonoscopy as currently recommended are low. Sex and age, potentially along with additional criteria,3 could guide potential risk-adapted extension of screening intervals beyond 10 years.