Endoscopic treatment for rectal neuroendocrine tumor: which method is better?

Abstract

Recently, research on rectal neuroendocrine tumors (NETs) has increased during the last few decades. Rectal NETs measuring <10 mm without atypical features and confined to the submucosal layer have only 1% risk of metastasis, and the long-term survival probability of patients without metastasis at the time of diagnosis is approximately 100%. Therefore, the current guidelines suggest endoscopic resection of rectal NETs of <10 mm is regarded as a safe therapeutic option. However, there are currently no clear recommendations for technique selection for endoscopic resection. The choice of treatment modality for rectal NETs should be based on the lesion size, endoscopic characteristics, grade of differentiation, depth of vertical involvement, lymphovascular invasion, and risk of metastasis. Moreover, the complete resection rate, complications, and experience at the center should be considered. Modified endoscopic mucosal resection is the most suitable resection method for rectal NETs of <10 mm, because it is an effective and safe technique that is relatively simple and less time-consuming compared with endoscopic submucosal dissection. Endoscopic submucosal dissection should be considered when the tumor size is >10 mm, suctioning is not possible due to fibrosis in the lesion, or when the snaring for modified endoscopic mucosal resection does not work well.

Treatment strategy and post‐treatment management of colorectal neuroendocrine tumor

“…13,[17][18][19] It is also reported that EMR-C can provide similarly high R0 resection rate for rectal NETs <10 mm. 13,19,20 Notably, the simpler EMR-C method, which does not require submucosal injection, has recently been proposed by a Chinese group, and its usefulness for rectal NET sized ≤10 mm has been demonstrated by a randomized noninferiority trial. 21 They compared the simplified EMR-C and ESD and proved the noninferiority of the EMR-C compared with ESD in terms of complete resection rate (EMR-C [38 cases] vs. ESD [41 cases]: 97.4% vs. 92.7%).…”

“…In addition to ESMR-L and EMR-C, several other procedures have been developed as modified EMR techniques for colorectal NETs, including EMR with circumferential incision/precutting, anchored snaretip EMR, and underwater EMR, and their usefulness has been reported. 13,19,[22][23][24][25] Despite ESMR-L and EMR-C's usefulness, the effectiveness and safety of these procedures are not guaranteed when the lesion size is larger than can be aspirated into a suction device or when a lesion is located in the colon with a risk of perforation. In this case, ESD can be useful.…”

Treatment of localized well-differentiated rectal neuroendocrine tumors: A focused review

“…[80] Reliable endoscopic resection should be performed using appropriate methods based on an accurate preoperative diagnosis. [81]…”

“…[80] Reliable endoscopic resection should be performed using appropriate methods based on an accurate preoperative diagnosis. [81] A multicenter prospective case accumulation is ongoing in Japan. Over 3 years from 2017 to 2019, 500 patients with colorectal NETs were enrolled, and 95.4% underwent endoscopic treatment.…”

A Review of Colonoscopy in Intestinal Diseases

“…mEMR includes EMR after circumferential precutting, EMR with cap, anchored snare-tip EMR, EMR with band ligation, and EMR using a dual-channel endoscope. mEMR overcomes the limitations of polypectomy and conventional EMR by capturing and excising the deep submucosa [ 128 ]. The type of endoscopic resection should be selected differently according to the size and shape of the lesion and invasion depth.…”