Moss A, Bourke MJ, Williams SJ et al.
University of Sydney, Sydney, NSW, Australia.
Gastroenterology 2011;140:1909–18.
Editor’s note: Sessile colon polyps are increasingly recognized and thought to be particularly likely to progress to cancer (JAMA 2008;229:1027–35). Endoscopic mucosal resection (EMR) is a minially invasive technique for removing large sessile polyps. A collaborative group in Australia designed this prospective observational study of all patients referred to them for EMR of sessile colorectal polyps ≥20 mm. In general, submucosal invasion was associated with flat lesions with a depressed component, a nongranular surface on white-light endoscopy, and with advanced, more irregular, pit pattern – all of which are objective criteria that had previously been used to describe features of certain colon polyps. The authors recommend that lesions with these features be managed surgically due to their increased association with submucosal invasion. EMR was effective at entirely removing the polyp in a single session in 89.2% of patients; risk factors for lack of efficacy included a previous attempt at EMR (odds ratio [OR] 3.75, 95% confidence interval [CI] 1.77–7.94; p=0.001) and ileocecal valve involvement (OR 3.38, 95% CI 1.20–9.52; p=0.021). Those cases that had previously been subject to EMR were particularly difficult to remove during subsequent procedures. When the investigators evaluated predictors of recurrence after effective EMR, large polyps (>40 mm) and previous use of an argon plasma coagulator were each associated with recurrence.