Endoscopic control of polyp burden and expansion of surveillance intervals in serrated polyposis syndrome.

BACKGROUND AND AIMS: Serrated polyposis syndrome (SPS) increases colorectal cancer risk. We describe the numbers of colonoscopies and polypectomies performed to achieve and maintain low polyp burdens, and the feasibility of expanding surveillance intervals in patients who achieve endoscopic control. METHODS: We retrospectively evaluated a prospectively collected database on 115 patients with SPS undergoing surveillance at Indiana University Hospital between June 2005 and May 2018. The endoscopist provided surveillance interval recommendations based on polyp burden. Endoscopic control was considered successful if surveillance examinations exhibited fewer polyps and if no or only an occasional polyp ≥1 cm in size was present at follow-up. Initial control was designated as the clearing phase and the maintenance phase was surveillance after control was established. RESULTS: In total, 87 patients (75.7%) achieved endoscopic control, with some others currently in the clearing phase. Achieving control required a mean of 2.84 colonoscopies (including the baseline) over 20.4 months and a mean total of 27.9 polyp resections. After establishing control, 71 patients were recommended to receive ≥24-month follow-up. Of those, 60 patients (69.0% of patients with initial control) continued surveillance at our center. The mean interval between colonoscopies during maintenance was 19.3 months with 6.74 mean polypectomies per procedure on polyps primarily <1 cm. There were no incident cancers or colon surgeries during maintenance. CONCLUSION: Most patients achieved control of polyp burden with 2 to 3 colonoscopies over 1 to 2 years. After reaching control, 60 patients returned at intervals up to 24 months with no incident cancers and no surgeries required. Expansion of surveillance intervals to 24 months is effective and safe for many patients with SPS who reach control of polyp burden.