RT Journal Article SR Electronic T1 Endoscopic mucosal resection for large serrated lesions in comparison with adenomas: a prospective multicentre study of 2000 lesions JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 644 OP 653 DO 10.1136/gutjnl-2015-310249 VO 66 IS 4 A1 Pellise, Maria A1 Burgess, Nicholas G A1 Tutticci, Nicholas A1 Hourigan, Luke F A1 Zanati, Simon A A1 Brown, Gregor J A1 Singh, Rajvinder A1 Williams, Stephen J A1 Raftopoulos, Spiro C A1 Ormonde, Donald A1 Moss, Alan A1 Byth, Karen A1 P'Ng, Heok A1 Mahajan, Hema A1 McLeod, Duncan A1 Bourke, Michael J YR 2017 UL http://gut.bmj.com/content/66/4/644.abstract AB Objective Endoscopic mucosal resection (EMR) is effective for large laterally spreading flat and sessile lesions (LSLs). Sessile serrated adenomas/polyps (SSA/Ps) are linked to the relative failure of colonoscopy to prevent proximal colorectal cancer. We aimed to examine the technical success, adverse events and recurrence following EMR for large SSA/Ps in comparison with large conventional adenomas.Design Over 74 months till August 2014, prospective multicentre data of LSLs ≥20 mm were analysed. A standardised dye-based conventional EMR technique followed by scheduled surveillance colonoscopy was used.Results From a total of 2000 lesions, 323 SSA/Ps in 246 patients and 1527 adenomas in 1425 patients were included for analysis. Technical success for EMR was superior in SSA/Ps compared with adenomas (99.1% vs 94.5%, p<0.001). Significant bleeding and perforation were similar in both cohorts. The cumulative recurrence rates for adenomas after 6, 12, 18 and 24 months were 16.1%, 20.4%, 23.4% and 28.4%, respectively. For SSA/Ps, they were 6.3% at 6 months and 7.0% from 12 months onwards (p<0.001). Following multivariable adjustment, the HR of recurrence for adenomas versus SSA/Ps was 1.7 (95% CI 0.9 to 3.0, p=0.097). Subgroup analysis by lesion size revealed an eightfold increased risk of recurrence for 20–25 mm adenomas versus SSA/Ps, but no significantly different risk between lesion types in larger lesion groups.Conclusion Recurrence after EMR of 20–25 mm LSLs is significantly less frequent in SSA/Ps compared with adenomatous lesions. SSA/Ps can be more effectively removed than adenomatous LSLs with equivalent safety. Ensuring complete initial resection is imperative for avoiding recurrence.Trial registration number ClinicalTrials.gov NCT01368289.