PWE-208 High prevalence of hyperplastic polyposis syndrome in the NHS bowel cancer screening programme: Abstract PWE-208 Table 1

Introduction Hyperplastic Polyposis Syndrome (HPS) is a rare syndrome (estimated 1:3000, 0.033% general population 1 ) in which multiple hyperplastic polyps can predispose to an increased risk of colorectal cancer of up to 7% at 5 years, 2 and a risk for first degree relatives of HPS patients of fivefold compared to the general population. 3 Proximal serrated polyps are commonly associated with advanced neoplasia. 4 Currently the Bowel Cancer Screening Programme (BCSP) does not offer surveillance for serrated polyps. We aimed to assess how common HPS is in our BCSP population. Methods We reviewed endoscopic and pathology records for all patients presenting for Bowel Cancer Screening in Oxfordshire between April 2010 (programme start) and January 2012. Three endoscopists performed the procedures. Patients were defined as HPS if they met either of the two main WHO criteria for HPS: either ≥20 hyperplastic polyps throughout the colon, or five hyperplastic polyps in the proximal colon with 2 ≥10 mm. Patients who were 1st degree relatives of HPS patients were not considered. Results In total 755 patients attended for screening colonoscopy. Five patients met WHO criteria for HPS, of whom three had a synchronous advanced adenoma (see Abstract PWE-208 table 1). The prevalence of HPS in our BCSP population was 0.66% (95% CI 0.24% to 1.52%), a 20-fold increase compared to the estimated rate in the general population. Abstract PWE-208 Table 1 Characteristics of patients diagnosed with HPS Age at index colonoscopy Gender No adenomas Largest adenoma and location No hyperplastic polyps in whole colon No hyperplastic polyps ≥10 mm in proximal colon* No hyperplastic polyps in proximal colon* No SSPs in whole colon Patient 1 69 M 7 13 mm sigmoid 21 2 12 1 Patient 2 64 F 1 15 mm sigmoid 24 5 24 4 Patient 3 62 M 8 32 mm sigmoid 37 0 5 8 Patient 4 64 M 2 8 mm descending 43 3 13 5 Patient 5 68 F 0 – 6 4 6 6 * Proximal colon is defined as proximal to the recto-sigmoid. SSP, sessile serrated polyp. Conclusion HPS appears to be relatively common in BCSP patients and is often associated with advanced neoplasia. Detection of a large serrated polyp or multiple hyperplastic polyps should alert BCSP colonoscopists to the possibility of HPS where they may wish to augment detection with dye-spray or advanced imaging techniques. BCSP surveillance for large proximal serrated polyps may need to be reviewed to ensure such patients are not overlooked. Competing interests None declared. References 1. Lockett MJ , Atkin WS. Gut 2001; 48 (Suppl I):A4. 18. 2. Boparai KS , et al. Gut 2010; 59 :1094–100. 3. Boparai KS , et al. Gut 2010; 59 :1222–5. 4. Hiraoka S , et al. Gastroenterology 2010; 139 :1503–10.