Background and aims
Endoscopic resection is recommended for the treatment of rectal neuroendocrine tumors (NET) ≤ 10 mm. However, there is no consensus on the preferred endoscopic modality for NET confirmed after biopsy, which may result in scar formation. This randomized study aimed to compare the efficacy of modified endoscopic mucosal resection (m-EMR) and endoscopic submucosal dissection (ESD) for treating rectal NET ≤ 10 mm, confirmed after biopsy.
METHODS
A multicenter, randomized controlled trial comparing m-EMR and ESD was done for rectal NET which was confirmed through forcep biopsy. The m-EMR technique included cap assisted EMR (EMR-C) and EMR with ligation (EMR-L). Primary endpoint was the rate for en bloc resection and curative resection, defined as achieving a clear resection margin with no lymphovascular invasion.
RESULTS
A total of 132 participants were randomized in a 1:1 into m-EMR and ESD group. Among them, tumors were not found after endoscopic resection in 20 patients. A total of 112 participants were included in the per protocol analysis: EMR-C, EMR-L; ESD. Safety was evaluated for all participants who were randomized. The rate for en bloc resection was 93.1% and 96.6% in the m-EMR and ESD group, respectively (p=679). The rate for curative resection was 86.2% and 93.1% in the m-EMR and ESD group, respectively (p=361). There was no incidence of perforation or delayed bleeding in either group.
CONCLUSIONS
For rectal NET ≤ 10 mm confirmed by biopsy, m-EMR demonstrated non-inferiority to ESD concerning en bloc resection and curative resection. The m-EMR is effective treatment modality for the treatment of rectal NET ≤ 10 mm confirmed by biopsy (trial number: KCT0006881).

Tae-Geun Gweon

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