In addition, there is increasing evidence, both in the scientific literature and at our institution, that there are identifiable factors at the initial EMR that predict recurrence at SC1. Current data from the ACE cohort suggests that increasing size of lesion (>=40mm), presence of high grade dysplasia (HGD) in the resection specimen and intra-procedural bleeding requiring endoscopic control predict greater likelihood of recurrence. The investigators have created, and have submitted for publication, a risk score for recurrence after EMR known as the Sydney EMR Recurrence Tool (SERT), (figure 1). SERT was created by binomial logistic regression analysis (figure 2) on 692 patients (model cohort) from the ACE study and validated on the remaining 691 patients (validation cohort) who had undergone SC1. Kaplan Meier curves (figure 3) were used to determine the predicted incidence of recurrence at various points in time after EMR on the validation cohort (figure 4). The strength of SERT lies in predicting the absence of recurrence, with negative predictive value of 92.6% at first surveillance colonoscopy. While this score was not derived from patients treated with SCAR technique, it is expected that the stratification of lesions by SERT will continue to be valid with lower overall rates.