Piecemeal endoscopic mucosal resection (pEMR) is the best approach to resect large lateral spreading tumors (LST, > 20 mm width). However, it is associated with early recurrence (ER) and late recurrence (LR). This study aims to assess the risk factors associated with ER and LR and to validate different predictive scores (SMSA, SERT, and BCM) in identifying the risk of ER and LR after LST resected by pEMR in a European cohort.

Retrospective observational cohort study, based on a prospectively collected database, of large LST submitted to pEMR.

A total of 108 patients were included in the study and the incidence rates of ER and LR were 22 % and 8 %, respectively. The lesion's size, SERT, and BCM scores were independent predictor factors of ER (p-value < 0.05), while the lesion's site and BCM score were independent predictor factors of LR (p-value < 0.05). For the prediction of ER, the SERT score (cut-off > 1) presented the highest AUROC (0.758 vs 0.697 from BCM and 0.647 from SMSA). Regarding LR, the BCM model (cut-off > 2) presented the highest AUROC (0.817 vs 0.708 from SERT and 0.691 from SMSA).

We present the first external validation of the three scores mentioned in an European cohort. SERT and BCM scores had an acceptable performance in predicting ER and LR. However, the BCM model was the only score that proved to be an independent predictor of both ER and LR, proving to be valuable for both applications.

1:  ESGE recommends cold snare polypectomy (CSP), to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of diminutive polyps (≤ 5 mm).Strong recommendation, high quality of evidence. 2:  ESGE recommends against the use of cold biopsy forceps excision because of its high rate of incomplete resection.Strong recommendation, moderate quality of evidence. 3:  ESGE recommends CSP, to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of small polyps (6-9 mm).Strong recommendation, high quality of evidence. 4:  ESGE recommends hot snare polypectomy for the removal of nonpedunculated adenomatous polyps of 10-19 mm in size.Strong recommendation, high quality of evidence. 5:  ESGE recommends conventional (diathermy-based) endoscopic mucosal resection (EMR) for large (≥ 20 mm) nonpedunculated adenomatous polyps (LNPCPs).Strong recommendation, high quality of evidence. 6:  ESGE suggests that underwater EMR can be considered an alternative to conventional hot EMR for the treatment of adenomatous LNPCPs.Weak recommendation, moderate quality of evidence. 7:  Endoscopic submucosal dissection (ESD) may also be suggested as an alternative for removal of LNPCPs of ≥ 20 mm in selected cases and in high-volume centers.Weak recommendation, low quality evidence. 8:  ESGE recommends that, after piecemeal EMR of LNPCPs by hot snare, the resection margins should be treated by thermal ablation using snare-tip soft coagulation to prevent adenoma recurrence.Strong recommendation, high quality of evidence. 9:  ESGE recommends (piecemeal) cold snare polypectomy or cold EMR for SSLs of all sizes without suspected dysplasia.Strong recommendation, moderate quality of evidence. 10:  ESGE recommends prophylactic endoscopic clip closure of the mucosal defect after EMR of LNPCPs in the right colon to reduce to reduce the risk of delayed bleeding.Strong recommendation, high quality of evidence. 11:  ESGE recommends that en bloc resection techniques, such as en bloc EMR, ESD, endoscopic intermuscular dissection, endoscopic full-thickness resection, or surgery should be the techniques of choice in cases with suspected superficial invasive carcinoma, which otherwise cannot be removed en bloc by standard polypectomy or EMR.Strong recommendation, moderate quality of evidence.

To systematically review and meta-analyze the efficacy and safety of salvage endoscopy for residual or recurrence of colorectal tumors after endoscopic resection.

Multiple databases including PubMed, EMBASE and the Cochrane Library were searched to screen for eligible studies and perform data extraction and pooled analysis.

Sixteen studies on salvage endoscopy for residual or recurrent colorectal cancer after endoscopic resection were included, covering approximately 994 patients. The results of the meta-analysis demonstrated that salvage endoscopic therapy for residual or recurrent colorectal tumors following endoscopic resection achieved an en bloc resection rate of 92% (95% CI 0.85-0.97; I2 = 91%) and an R0 resection rate of 82% (95% CI 0.75-0.87; I2 = 78%). The rates of intraoperative or postoperative bleeding and perforation were 10%/1% and 5%/2%, and the recurrence rate was 2%.

Salvage endoscopic resection is an effective and safe treatment strategy for residual or recurrent colorectal tumors after endoscopic resection.

Polyp recurrence is common after endoscopic mucosal resection (EMR) of non-pedunculated colonic polyps ≥ 20 mm. Two models haven been published for polyp recurrence prediction: Sydney EMR recurrence tool (SERT) and the size, morphology, colonic site, and access to target (SMSA) score. None of these models have been evaluated in a real-world United States (U.S.) cohort. We aimed to evaluate the external validity of these two models and develop a new model.

Retrospective cohort study of patients with non-pedunculated polyps ≥ 20 mm that underwent EMR between 1/1/2012 and 6/30/2020. Univariate and multivariate analysis were performed to identify predictors of polyp recurrence to build a new model. Receiver Operating Characteristic (ROC) curves for the new model, SERT and a modified version of SMSA were derived and compared.

A total of 461 polyps from 461 unique patients were included for analysis. The average polyp size was 29.1 ± 12.4 mm. Recurrence rate at first or second surveillance colonoscopy was 29.0% at a 15.6 months median follow up (IQR 12.3-17.4). A model was created with 4 variables from index colonoscopy: size > 40 mm, tubulovillous adenoma histology, right colon location and piecemeal resection. ROC curves showed that the Area Under the ROC (AUC) for the new model was 0.618, for SERT 0.538 and for mSMSA 0.550.

SERT score and mSMSA have poor external validity to predict polyp recurrence after EMR of non-pedunculated polyps > 20 mm. Our new model is simpler and performs better in this multiethnic, non-referral cohort from the U.S.

In the last years, endoscopic techniques gained a crucial role in the treatment of colorectal flat lesions. At the same time, the importance of a reliable assessment of such lesions to predict the malignancy and the depth of invasion of the colonic wall emerged. The current unsolved dilemma about the endoscopic excision techniques concerns the necessity of a reliable submucosal invasive cancer assessment system that can stratify the risk of the post-procedural need for surgery. Accordingly, this narrative literature review aims to compare the available diagnostic strategies in predicting malignancy and to give a guide about the best techniques to employ. We performed a literature search using electronic databases (MEDLINE/PubMed, EMBASE, and Cochrane Library). We collected all articles about endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) registering the outcomes. Moreover, we analyzed all meta-analyses comparing EMR vs ESD outcomes for colorectal sessile or non-polypoid lesions of any size, preoperatively estimated as non-invasive. Seven meta-analysis studies, mainly Eastern, were included in the analysis comparing 124 studies and overall 22954 patients who underwent EMR and ESD procedures. Of these, eighty-two were retrospective, twenty-four perspective, nine case-control, and six cohorts, while three were randomized clinical trials. A total of 18118 EMR and 10379 ESD were completed for a whole of 28497 colorectal sessile or non-polypoid lesions > 5-10 mm in size. In conclusion, it is crucial to enhance the preoperative diagnostic workup, especially in deciding the most suitable endoscopic method for radical resection of flat colorectal lesions at risk of underlying malignancy. Additionally, the ESD necessitates further improvement because of the excessively time-consuming as well as the intraprocedural technical hindrances and related complications. We found a higher rate of en bloc resections and R0 for ESD than EMR for non-pedunculated colorectal lesions. Nevertheless, despite the lower local recurrence rates, ESD had greater perforation rates and needed lengthier procedural times. The prevailing risk for additional surgery in ESD rather than EMR for complications or oncologic reasons is still uncertain.