Colon mucosal neoplasia referred for endoscopic mucosal resection: Recurrence of adenomas and prediction of submucosal invasion

Background Endoscopic mucosal resection (EMR) is an effective and minimally invasive alternative to surgery for large polyps and laterally spreading lesions. Gross morphology and surface characteristics may help predict submucosal invasion of the lesion (SMIL) during endoscopic evaluation. This is one of the largest single-center studies reporting endoscopic mucosal resection for larger (≥ 20 mm) colorectal lesions in the United States. Aim To determine the recurrence rate of adenomas and endoscopic features that may predict submucosal invasion of colonic mucosal neoplasia. Methods This is a retrospective cohort study of all the patients referred for endoscopic mucosal resection for lesions ≥ 20 mm, spanning a period from January 2013 to February 2017. The main outcome measure was identifying features that may predict submucosal invasion of mucosal lesions and predict recurrence of adenomas on follow-up surveillance colonoscopy performed at 4-6 mo. Results A total of 480 patients with 500 lesions were included in the study. The median age was 68 (Inter quantile range: 14) with 52% males. The most common lesion location was ascending colon (161; 32%). Paris classification 0-IIa (Flat elevation of mucosa - 316; 63.2%); Kudo Pit Pattern IIIs (192; 38%) and Granular surface morphology (260; 52%) were most prevalent. Submucosal invasion was present in 23 (4.6%) out of 500 lesions. The independent risk factors for SMIL were Kudo Pit Pattern IIIL + IV and V (Odds ratio: 4.5; P value Conclusion There was overall low prevalence of SMIL in our study. Kudo pit pattern (IIIL + IV and V) and Paris classification 0-IIc were the only factors identified as an independent risk factor for submucosal invasion. The independent risk factor for recurrence was adenoma size (> 40 mm). Almost all recurrences (98.8%) were treated endoscopically.