Comparison of Conventional and Modified Endoscopic Mucosal Resections for the Treatment of Rectal Neuroendocrine Tumors.

Background/Aims Small rectal neuroendocrine tumors (NETs) can be resected endoscopically. This study aimed to determine whether modified endoscopic mucosal resections (EMRs), including EMR with ligation (EMR-L), EMR with precutting (EMR-P), and strip biopsy, are superior than the conventional EMR (cEMR) in achieving histological complete and curative resections for the treatment of rectal NETs. Methods The medical records of 215 patients who were treated with endoscopic resections for well-differentiated rectal NETs <1.5 cm in size between January 2011 and July 2017 were retrospectively evaluated. Of the patients, 110, 33, 29, and 43 were treated with cEMR, EMR-P, EMR-L, and strip biopsy, respectively. For each method, histological complete resection (negative resection margin) and curative resection rates (negative resection margin with no lymphovascular invasion) were calculated. Results The histological complete resection rates for cEMR, EMR-P, EMR-L, and strip biopsy were 74.5%, 90.9%, 93.1%, and 90.7%, respectively, and the cEMR was significantly inferior to the modified EMRs (p=0.045 for cEMR vs EMR-P, p=0.031 for cEMR vs EMR-L, p=0.027 for cEMR vs strip biopsy, and p=0.001 for cEMR vs modified EMRs). The curative resection rates were 58.2%, 84.8%, 82.8%, and 76.7% for cEMR, EMR-P, EMR-L, and strip biopsy, respectively, and cEMR was significantly inferior to the modified EMRs (p=0.006 for cEMR vs EMR-P, p=0.018 for cEMR vs EMR-L, p=0.041 for cEMR vs strip biopsy, and p=0.000 for cEMR vs. modified EMRs) (Table 1). No significant differences were observed in en bloc resection (p=0.096) and complication rates (p=0.071) but EMR-P required longer procedure time (p=0.000). Conclusions The modified EMR techniques were better than the conventional EMR in accomplishing histological complete and curative resections for the endoscopic treatment of rectal NETs. [ABSTRACT FROM AUTHOR]