ATU-05 Experience of endoscopic submucosal dissection (ESD) for treatment of gastrointestinal neuroendocrine tumors (NETs)

Introduction Although endoscopic submucosal dissection (ESD) of gastrointestinal (GI) neuroendocrine tumor (NETs) is an increasingly performed minimally invasive technique allowing complete en-bloc resection of mucosal and submucosal lesions, efficacy and safety outcome is limited. The aim of this study is to review two European centers experience of endoscopic treatment of superficial GI NET by ESD. Methods Clinical and technical data of patients treated by ESD from two tertiary European centers were prospectively collected from October 2014 to February 2019. Complete resection (R0) was defined as clear lateral and vertical margins. Results Twenty-four ESDs of NET were performed in 22 patients (females 59%), mean age of 54.8 years. Fifteen NETs (66%) were removed from the stomach, 6 from the rectum (25%), 1 from the esophagus (4%) and 1 from the duodenum (4%). 87.5% of gastric NETs were associated with atrophic gastritis (86.6% of which of autoimmune etiology) and 56% with previous history of multiples NETs. En-bloc resection was achieved in all patients (100%). R0 resection rate was 75% (91.6% clear lateral and 79% clear vertical margins). Lymphovascular infiltration was seen in one case (4%). Median ESD duration time was 77 min (20–240). Two cases presented small perforations, treated conservatively by antibiotics and clip closure. The median specimen size was of 25 mm (12–50). Pathological examination showed 58.3% grade 1, 37.5% grade 2 and 4% grade 3 NETs. Sixteen lesions were characterized as pT1 (72.7%). Three patients were candidates for additional treatment: one had endoscopic mucosal resection for additional known lesions, one underwent surgery with oncological lymph node resection (finally pT2N1) and one refused systemic therapy. At the end of a median follow-up of 18 months, two cases of recurrence were identified: one was managed endoscopically, the second refused treatment. Conclusions Our series of ESD for selected GI NETs showed favorable results in term of efficacy and safety. However, further studies are needed to determine the role of ESD compared to other resection modalities.