Long-term outcome of endoscopic and surgical resection for foregut neuroendocrine tumors

OBJECTIVE: Endoscopic resection (ER) of foregut neuroendocrine tumors (NETs) is increasingly performed instead of surgery. This study aimed to compare the long-term therapeutic outcomes of ER and surgical resection (SR) for foregut NETs. METHODS: From 2002 to 2012, a total of 49 patients with histologically confirmed foregut NETs were treated by ER (n = 33) and SR (n = 16). The clinicopathological characteristics and therapeutic outcomes were evaluated. RESULTS: Of the 33 patients who underwent ER [ endoscopic mucosal resection (n = 26), endoscopic mucosal dissection(n = 7)], 32 were diagnosed as NET-G1 and NET-G2, and the other as neuroendocrine carcinoma (NEC). Of the 16 patients who underwent SR, 10 were diagnosed as NET-G1, 2 as NET-G2 and 4 as NEC. The median tumor size was significantly smaller in the ER group compared with the SR group (7 mm vs 19 mm, P = 0.001). In almost all patients treated with ER (32/33), NET invasion was limited to the mucosa and submucosa. Non-curative resections were observed in 24.2% of the patients in the ER group (8/33) and 25.0% in the SR group (4/16). No recurrence occurred in NET cases with positive resection margins by ER. However, all cases of non-curative resection with lymphatic invasion (one in the ER group and four in the SR group) developed liver metastasis during the follow-up despite complete resection, and all these five patients has histologically confirmed NECs. CONCLUSION: NET patients treated by ER may have a good prognosis if the tumor size is small and histologically low grade without lymphatic invasion.