Cho JW, et al. Clin Endosc. 2014 Nov;47(6):523-529. http://dx.doi.org/10.5946/ce.2014.47.6.523

Background and study aims: Rectal carcinoid tumors are often found incidentally during screening colonoscopy and can be resected using various endoscopic techniques. This study aimed to compare the safety and efficacy of endoscopic submucosal dissection (ESD) with endoscopic mucosal resection (EMR) for rectal carcinoid tumors. Patients and methods: Between January 2003 and June 2009, 74 patients (74 lesions) underwent either EMR (n = 28) or ESD (n = 46) for rectal carcinoid tumors. The rate of endoscopic complete resection, pathological complete resection, procedure complications, and tumor recurrence were analyzed retrospectively. Results: The endoscopic complete resection rate was significantly higher in the ESD group (46 lesions, 100 %) compared with the EMR group (25 lesions, 89.3 %) (P = 0.049). The pathological complete resection rate was higher in the ESD group (38 lesions, 82.6 %) compared with the EMR group (18 lesions, 64.3 %); however, this difference was borderline significant (P = 0.067). Overall complication rate was not significantly different between the EMR group (3.6 %) and the ESD group (6.3 %). There was one case of remnant lesion in the EMR group, which was managed by ESD, and no recurrence has been detected in either the EMR or ESD groups. Conclusion: This study suggests that ESD might be a feasible treatment technique for small rectal carcinoid tumors. It showed superior efficacy and comparable safety to EMR.

Background and aim: Endoscopic mucosal resection (EMR) is currently not accepted as an alternative treatment to surgery in early gastric cancer (EGC) of the undifferentiated histologic type. The present retrospective analysis examined the correlation of various histologic factors with the presence of lymph node metastasis (LNM). Patients and methods: A retrospective analysis on 234 patients with poorly differentiated EGC who underwent radical gastrectomy with D2 lymph node dissection was undertaken. Several clinicopathologic factors were investigated to identify predictive factors for LNM: age, sex, type of operation, tumor location, tumor size, gross type, ulceration, lymphatic invasion, and depth of invasion. Results: Of the 234 lesions with poorly differentiated EGC, half (n = 116) already showed submucosal invasion in the resection specimen; 25.9 % of those (30/116) were limited to the upper third (SM1). Of the lesions confined to the mucosa, LNM was found in 3.4 % (4/118). With minor submucosal infiltration (SM1), the LNM rate was lower (0/30) in our patient population. Only with SM2/3 infiltration did the LNM rate sharply rise to around 30 %. The cut-off for submucosal infiltration depth was 500 μm (0/32 LNM), above which LNM rates were substantial (31.2 %; 24/77). There was limited correlation between the SM1-3 classification and actual measurement of submucosal infiltration depth. In a multivariate analysis, tumor size (P = 0.033), depth of invasion (P = 0.004), and lymphatic invasion (P < 0.001) were associated with LNM. Conclusion: Poorly differentiated EGC confined to the mucosa or with minimal submucosal infiltration (≤ 500 μm) could be considered for curative EMR due to the low risk of LNM. Given the limited case number of subgroups, these findings should be confirmed by more data from other centers, which should also focus on local recurrence after EMR in poorly differentiated EGC.

To clarify the short and long-term results and to prove the usefulness of endoscopic resection in type 3 gastric neuroendocrine tumors (NETs). Of the 119 type 3 gastric NETs diagnosed from January 1996 to September 2011, 50 patients treated with endoscopic resection were enrolled in this study. For endoscopic resection, endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) was used. Therapeutic efficacy, complications, and follow-up results were evaluated retrospectively. EMR was performed in 41 cases and ESD in 9 cases. Pathologically complete resection was performed in 40 cases (80.0%) and incomplete resection specimens were observed in 10 cases (7 vs 3 patients in the EMR vs ESD group, P = 0.249). Upon analysis of the incomplete resection group, lateral or vertical margin invasion was found in six cases (14.6%) in the EMR group and in one case in the ESD group (11.1%). Lymphovascular invasions were observed in two cases (22.2%) in the ESD group and in one case (2.4%) in the EMR group (P = 0.080). During the follow-up period (43.73; 13-60 mo), there was no evidence of tumor recurrence in either the pathologically complete resection group or the incomplete resection group. No recurrence was reported during follow-up. In addition, no mortality was reported in either the complete resection group or the incomplete resection group for the duration of the follow-up period. Less than 2 cm sized confined submucosal layer type 3 gastric NET with no evidence of lymphovascular invasion, endoscopic treatment could be considered at initial treatment.