EPoS II (NEJM): first surveillance colonoscopy after high-risk adenoma removal can be done at 5 years instead of 3

In the randomised EPoS II noninferiority trial, 10,799 people from eight European countries who had had a high-risk adenoma removed were assigned to a first surveillance colonoscopy at 5 or at 3 years (3 years being the current guideline recommendation). In an interim analysis after 5.5 years of follow-up, the cumulative incidence of colorectal cancer was 0.77% with less-frequent surveillance and 0.82% with more-frequent surveillance (difference −0.05 percentage points); the upper confidence bound of 0.68 fell within the prespecified margin of 0.7 points, meeting the noninferiority criterion. Five patients died of colorectal cancer: 3 (0.06%) in the 5-year group and 2 (0.04%) in the 3-year group. This is an interim result — the trial’s primary end point is incidence at 10 years, and the timing of surveillance for any individual patient remains a decision for the treating clinician.