PTH-062 Endoscopic Mucosal Resection of Large Colorectal Polyps in Non Screening Colonoscopies Has a High Recurrence Rate:

Introduction EMR of large colorectal polyps has been reported to be a safe and effective technique in UK. Although the success of large polyp EMR has been reported within regional bowel cancer screening centres, there is a paucity of data comparing outcomes between screening and non-screening centres. Methods A total of 61 screening and 60 non-screening EMR of polyps 2cm or greater were performed from January 2008 to December 2011. Data was collected from 3 hospitals for screening EMR and 1 district hospital for non-screening EMR. Results The table below summarises the findings at initial EMR for both groups. Abstract PTH-062 Table 1 Characteristics Results for Screening group n (%) Results for non-screening group n (%) Number of patients 61 60 Mean size (in mm) 35 43 Location (Left colon) 43(70) 36(60) Histology (Low Grade Dysplasia) 47(83) 36(67) Histology (High Grade Dysplasia) 7(12) 11(20) Histology (Adenocarcinoma) 3(5) 7(13) Bleeding Complication 2(3) 3(5) Perforation 0(0) 1(2) Surveillance data was available for 37 patients in the non-screening group compared to all 61 patients in the screening group up-to 3 months post EMR. Number of recurrences were 6 (10%) with mean polyp size of 25mm in the screening group compared to 10 (27%) in the non screening group with mean polyp size of 50mm. All recurrences in both groups were resected and complete. Histology confirmed low grade dysplasia (LGD) in 80%, while 2 patients had evidence of high grade dysplasia (HGD) in the non-screening group. All showed LGD in the screening group. At 12 months surveillance post EMR, 43 screening patients had follow-up data with 8 recurrences detected compared to 14 in the non screening group with 4 recurrences. Conclusion Endoscopic mucosal resection of polyps in screening group appears to be safer with low complication rates and low recurrence rate up to 12 months post EMR compared to the non-screening groups. This may be due to a multitude of factors such as patient age, co-morbidites and the characteristics of polyps. Clinical features of patients undergoing EMR were similar in both groups. There was a trend to higher recurrence and complication rate in the non screening group. The follow up post EMR was less consistent in the non screening group possibly due to less stringent protocols for follow up. This may have affected the surveillance and recurrence rates. Disclosure of Interest None Declared. References Lim TR, Mahesh V, Singh S, et al. Endoscopic mucosal resection of colorectal polyps in typical UK hospitals. World J Gastroenterol.2010; 16(42): 5324–8. Boix J, Lorenzo-Zúñiga V, Moreno de Vega V, et al. Endoscopic removal of large sessile colorectal adenomas: is it safe and effective? Dig Dis Sci 2007; 52: 840–844 Salama M, Ormonde D, Quach T, et al. Outcomes of endoscopic resection of large colorectal neoplasms: an Australian experience. J Gastroenterol Hepatol 2010; 25: 84–89