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.