Adenoma recurrence after piecemeal colonic EMR is predictable: the Sydney EMR recurrence tool

Background and Aims EMR is the primary treatment of large laterally spreading lesions (LSLs) in the colon. Residual or recurrent adenoma (RRA) is a major limitation. We aimed to identify a robust method to stratify the risk of RRA. Methods Prospective multicenter data on consecutive LSLs ≥20 mm removed by piecemeal EMR from 8 Australian tertiary-care centers were included (September 2008 until May 2016). A logistic regression model for endoscopically determined recurrence (EDR) was created on a randomly selected half of the cohort to yield the Sydney EMR recurrence tool (SERT), a 4-point score to stratify the incidence of RRA based on characteristics of the index EMR. SERT was validated on the remainder of the cohort. Results Analysis was performed on 1178 lesions that underwent first surveillance colonoscopy (SC1) (median 4.9 months, interquartile range [IQR] 4.9-6.2). EDR was detected in 228 of 1178 (19.4%) patients. LSL size ≥40 mm (odds ratio [OR] 2.47; P <.001), bleeding during the procedure (OR 1.78; P =.024), and high-grade dysplasia (OR 1.72; P =.029) were identified as independent predictors of EDR and allocated scores of 2, 1, and 1, respectively to create SERT. Lesions with SERT scores of 0 (SERT = 0) had a negative predictive value of 91.3% for RRA at SC1, and SERT was shown to stratify RRA to specific follow-up intervals by using Kaplan Meier curves (log-rank P <.001). Conclusions Guidelines recommend SC1 within 6 months of EMR. SERT accurately stratifies the incidence of RRA after EMR. SERT = 0 lesions could safely undergo first surveillance at 18 months, whereas lesions with SERT scores between 1 and 4 (SERT 1-4) require surveillance at 6 and 18 months. (Clinical trial registration number: NCT01368289.)