Clinical outcomes of endoscopic mucosal resection for rectal neuroendocrine tumor

Abstract

BackgroundThe incidence of rectal neuroendocrine tumors (NETs) is rapidly increasing because of the frequent use of endoscopic screening for colorectal cancers. However, the clinical outcomes of endoscopic resection for rectal NETs are still unclear. The aim of this study was to assess the rates of histologically complete resection (H-CR) and recurrence after endoscopic mucosal resection (EMR) for rectal NETs.MethodsA retrospective analysis was performed on patients who underwent EMR for rectal NETs between January 2002 and March 2015 at Seoul National University Hospital. Primary outcomes were H-CR and recurrence rates after endoscopic resection. H-CR was defined as the absence of tumor invasion in the lateral and deep margins of resected specimens.ResultsAmong 277 patients, 243 (88%) were treated with conventional EMR, 23 (8%) with EMR using a dual-channel endoscope, and 11 (4%) with EMR after precutting. The median tumor size was 4.96 mm (range, 1–22) in diameter, and 264 (95%) lesions were confined to the mucosa and submucosal layer. The en-bloc resection rate was 99% and all patients achieved endoscopically complete resection. The H-CR rates were 75, 74, and 73% for conventional EMR, EMR using a dual-channel endoscope, and EMR after precutting, respectively. Multivariate analysis showed that H-CR was associated with tumor size regardless of endoscopic treatment modalities (p = 0.023). Of the 277 patients, 183 (66%) underwent at least 1 endoscopic follow-up. Three (2%) of these 183 patients had tumor recurrence, which was diagnosed at a median of 62.5 months (range 19–98) after endoscopic resection. There was 1 case of disease-related death, which occurred 167 months after endoscopic treatment because of bone marrow failure that resulted from tumor metastasis.ConclusionsAlthough the en-bloc resection rate was 99% in rectal NETs, H-CR rates were 72–74% for various EMR procedures. H-CR may be associated with tumor size regardless of endoscopic treatment modalities.

O 6-Methylguanine DNA Methyltransferase and Glucose Transporter 2 in Foregut and Hindgut Gastrointestinal Neuroendocrine Neoplasms

“…These results were also consistent with the association of MGMT downregulation with progression of malignant tumors [20,22]. In GI-NET patients, less invasive therapy such as endoscopic submucosal dissection or mucosal resection have often been administered [34] It is therefore important to predict the clinical course of these patients, especially with respect to the status of lymph node metastasis, during histological evaluation of biopsy specimens. MGMT scoring system could therefore contribute to stratify the clinical outcome of GI-NET G1 patients.…”

The outcomes of modified endoscopic mucosal resection and endoscopic submucosal dissection for the treatment of rectal neuroendocrine tumors and the value of endoscopic morphology classification in endoscopic resection

“…However, the outcomes of different ER techniques have been shown to vary in different studies [11,12], and the optimal type of ER is still controversial. M-EMR was developed from EMR and includes EMR with cap (EMR-C), EMR with ligation (EMR-L), EMR with circumferential incision (EMR-CI) and EMR using a dual-channel endoscope; these have all been proven to be safe and effective methods for treating rectal NETs [13][14][15][16][17] and have been widely used around the world. ESD has also been reported to have higher en bloc and complete resection rates than conventional EMR [9], although ESD is slightly more complicated and time consuming than EMR and m-EMR.…”

“…These factors should be considered in the preoperative evaluation combined with examinations such as EUS, CT, and MRI to identify muscularis invasion as well as lymph node or distant metastasis before ER. Factors associated with incomplete resection represent another aspect that should be highlighted, and these factors include lesion size [15], central depression on the surface [20] and location [21]. Of note, endoscopic appearance is related to both metastasis and incomplete resection.…”

Effectiveness of underwater endoscopic mucosal resection versus conventional endoscopic mucosal resection for 10 to 20 mm colorectal polyps

“…[ 5 – 7 ] While conventional EMR has some limitations. [ 8 – 12 ] Submucosal injection may displace the polyp into a less accessible location and constrict the lumen, making it more difficult to access the lesion. [ 8 , 9 ] Incidence of residual or recurrent after conventional EMR is remarkably high.…”

“…[ 10 ] It mandates subsequent more frequent surveillance colonoscopy and increases financial burden for patients. [ 11 , 12 ]…”