Endoscopic Treatment Strategy for Large Laterally Spreading Tumor: Endoscopic Piecemeal Mucosal Resection or Endoscopic Submucosal Dissection

Background/Aims: The therapeutic strategy between endoscopic piecemeal mucosal resection (EPMR) and endoscopic submucosal dissection (ESD) for large laterally spreading tumors (LSTs) has not been clearly defined. The aim of this study was to compare the clinical outcomes between EPMR and ESD in patients with large LST. Methods: From July 2006 to September 2010, 106 patients who underwent endoscopic resection for large (>20 mm) LSTs were included in our retrospective analysis. Results: Baseline characteristics of the patients and tumors were not different between two groups except for location (EPMR-right colon, ESD-rectum). The en bloc resection rate and complete resection rate were significantly higher in the ESD group than those in the EPMR group (EPMR vs. ESD, 53.5% vs. 88.6, P<0.01, 45.1% vs. 71.4%, P=0.01, respectively). However, total procedure time was significantly shorter in the EPMR group (21.3 min vs. 44.4 min, P<0.01). Furthermore, the rates of complication including perforation and bleeding were significantly lower in the EPMR group than those in the ESD group (perforation, 1.4% vs. 11.4%, P=0.02; bleeding, 4.2% vs. 17.1%, P=0.03, respectively). During 19.9 months of follow-up, no significant difference was observed in terms of recurrence (1.5% vs. 3.2%). Non-granular, pseudo-depressed type (LST-PD) showed a significantly higher presence of adenocarcinoma and deeper submucosal invasion than other types of LSTs. Conclusions: The therapeutic strategy for choosing between EPMR and ESD for large LST lesions should be determined based on the macroscopic findings of their subtype. En bloc resection with ESD should be applied to LST-PDs due to their higher rate of submucosal invasion.