Long-term follow up of endoscopic resection for type 3 gastric NET

Abstract

Aim: To clarify the short and long-term results and to prove the usefulness of endoscopic resection in type 3 gastric neuroendocrine tumors (NETs).

Methods: 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.

Results: 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.

Conclusion: 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.

Keywords: Carcinoid; Endoscopic resection; Neuroendocrine tumor; Stomach; Treatment.

Figure 1

Flow chart of type 3 gastric neuroendocrine tumors. Of all type 3 gastric neuroendocrine tumors (NETs) (n = 119), 39 patients were treated with surgery, 50 patients were treated using an endoscopic method, and 15 patients were followed up only by observation. In the endoscopic treatment group, 41 patients were treated with endoscopic mucosal resection (EMR), and nine patients were treated with endoscopic submucosal dissection (ESD). Upon analysis of the resected specimens, histologically incomplete resections were found in seven cases in the EMR group and three cases in the ESD group, and lymphovascular invasion was found in one case in the EMR group and two cases in the ESD group. All cases of lymphovascular invasion were treated with an additional operation. During the median follow-up duration (46 mo), there was no recurrence of gastric NETs in the endoscopic resection group.