Optimal endoscopic treatment for rectal neuroendocrine tumors, confirmed after forceps biopsy: A Korean Association for the Study of Intestinal Diseases multicenter, randomized non-inferiority trial

Abstract

Background and aims: Insufficient submucosal lifting because of pretreatment with forceps biopsy frequently complicates endoscopic treatment of rectal neuroendocrine tumors (NETs) and potentially affects procedural outcomes. Despite advances in endoscopic techniques, the optimal approach for achieving R0 resection in such cases remains to be clarified. This study aimed to investigate the optimal endoscopic technique for treating biopsy-proven rectal NETs ≤10 mm.

Methods: A multicenter, randomized noninferiority study was conducted to evaluate the noninferiority of modified EMR (m-EMR), including cap-assisted EMR and EMR with ligation, compared with endoscopic submucosal dissection (ESD), in achieving complete resection of small rectal NETs that were confirmed with forceps biopsy. The primary outcome was the complete resection rate, with a noninferiority margin of -10%. Secondary outcomes included adverse events and procedural time.

Results: Of the 132 participants randomized into 2 groups, 116 were included in the final analysis (m-EMR, n = 56; ESD, n = 60). The complete resection rate was 85.7% (48/56) for m-EMR and 91.7% (55/60) for ESD (rate difference: -6.0%; 95% CI, -17.5% to 5.6%), which failed to demonstrate noninferiority. No perforation or delayed bleeding events were observed in either group.

Conclusions: The m-EMR did not demonstrate noninferiority to ESD for complete resection of biopsy-proven rectal NETs ≤10 mm. Thus, when both m-EMR and ESD are accessible, m-EMR may not be the preferred resection modality in patients subjected to preresection forceps biopsy. Further studies are needed to explore the potential role of m-EMR in resource-limited settings (trial number: KCT0006881).