Risk of metachronous neoplasia on surveillance colonoscopy among young and older patients after polypectomy.

Background And Aims: Few reports address the appropriate colonoscopy surveillance interval for individuals <50-years-old. We compared the risk of metachronous neoplasia among young (<50 years), adult (50-74 years) and older (≥75 y) age groups.

Methods: This was a single center retrospective cohort study. Eligible subjects underwent their first colonoscopy with polypectomy between 2005 and 2014 and had at least one surveillance colonoscopy 3-5 years later. Patients (N = 495) were stratified at baseline into low-risk adenoma (LRA) and advanced adenoma groups. Study outcomes were overall and high-risk neoplasia at surveillance colonoscopy.

Results: In the baseline LRA-group (N = 201), the 5-year risk of metachronous high-risk neoplasia was 12.5%, 15.2% and 22.5% (P = 0.426) in the young, adult and older age groups, respectively. In the baseline advanced adenoma group (N = 294), the 3-year risk of metachronous high-risk neoplasia was 13.3%, 14.8% and 25.3% (P = 0.041), respectively. In multivariate analysis, the only risk factor for metachronous high-risk neoplasia was older age (OR 1.876, CI 1.087-3.238; P = 0.024).

Conclusions: Considering the comparable risk of metachronous high-risk neoplasia in young and adult patients, surveillance recommendations after polypectomy should not differ. Since this risk is higher among older people, more frequent surveillance schedule can be considered for this age group but should be individualized.