Clinical Outcomes of Patients with Small Rectal Neuroendocrine Tumors Treated Using Endoscopic Submucosal Resection with a Ligation Device

Abstract

Background/Aims: The therapeutic strategies for small rectal neuroendocrine tumors (NETs) have not been standardized. We examined the efficacy and safety of endoscopic submucosal resection with a ligation device (ESMR-L) and the long-term outcomes after endoscopic treatment. Methods: A total of 181 patients with rectal NETs <10 mm who were treated between May 2002 and May 2017 were retrospectively enrolled. All the lesions had been resected using ESMR-L, and the follow-up strategies were determined according to the pathological examinations. The long-term outcomes after a 53-month follow-up period were also evaluated. Results: R0 resection was achieved in 180 cases (99.4%). Lymphovascular invasion was confirmed in 67 cases (37.0%), while a curative resection was achieved in 114 cases (63.0%). One perforation (0.6%) and 11 cases with delayed bleeding (6.1%) were observed. A multivariate logistic regression analysis revealed that a tumor size > 5 mm (OR 2.06; 95% CI 1.04–4.08, p = 0.04) was a significant independent predictor of the presence of lymphovascular invasion. Of the 67 patients with non-curative resections, 11 patients underwent additional surgery; lymph node metastasis was confirmed in 2 cases (18.2%). No local or distant metastases were observed during the follow-up period in 77 patients with a curative resection, 9 patients who received additional surgery, and 50 patients with non-curative resections. Conclusion: ESMR-L is an easy, safe and effective treatment for rectal NETs <10 mm in diameter, and the prognosis of patients seems to be good, despite a relatively high rate of lymphovascular invasion.

Management of Gastrointestinal Neuroendocrine Tumors

“…Complete gross and microscopic resection was achieved in 180 cases (99.4%), and 77 patients out of a total of 136 patients had curative resection at long-term follow-up. 105 Endoscopic submucosal dissection has advantage over EMR of en bloc resection of lesions regardless of size and including some tumors extending into the submucosa. However, ESD is associated with a higher perforation rate compared with EMR.…”

“…Complete gross and microscopic resection was achieved in 180 cases (99.4%), and 77 patients out of a total of 136 patients had curative resection at long-term follow-up. 105…”

Relevant risk factors and the prognostic impact of positive resection margins after endoscopic resection of gastrointestinal neuroendocrine tumors.

“…As a minimally invasive technique, endoscopic resection may benefit patients diagnosed with gastrointestinal neuroendocrine tumors. Recently, endoscopic submucosal dissection has been adopted as treatment for digestive tract submucosal tumors and was found to be effective [6,7]. However, a significant difference was observed in the occurrence rate of positive resection margins after endoscopic resection.…”

Modified endoscopic mucosal resection techniques for treating precancerous colorectal lesions

“…Similar conclusions were reached by a prospective, multicenter trial where ESMR-L not only achieved a significantly higher complete resection rate compared to C-EMR (42/45, 93.3% vs. 36/55, 65.5%, P=0.001) for same-size tumors, but also an equivalent complication rate (2/45, 4.4% vs. 0/55, 0.0%, P=0.2) [ 73 ]. In another study, ESMR-L once again outperformed C-EMR in terms of histologically complete resection (27/29, 93.1% vs. 82/110, 74.5%, P=0.03) for rectal neuroendocrine tumors with average size 7 mm, while at the same time the technique also showed valuable results in the long term [ 74 , 75 ]. Preliminary data suggested that the method even achieves at least equal resection outcomes to ESD for rectal carcinoid tumors <10 mm in size (complete resection rate 24/29, 82.8% vs. 25/31, 80.6% P=0.83) [ 76 ]; however, more recently it was shown that ESMR-L may in fact be even more superior to ESD for similar lesions, with respect to therapeutic outcomes and procedure time (95.5% vs.75.0%, P=0.02 for complete resection rate and 7.1±4.5 vs. 24.2±12.1 min, P<0.001, for resection time, respectively) [ 77 ].…”