Neuroendocrine tumors of the stomach: chemotherapy with cisplatin plus irinotecan is effective for gastric poorly-differentiated neuroendocrine carcinoma

Neuroendocrine tumors (NETs) occur in various primary sites, but rarely in the stomach. NETs are classified into three types, carcinoids, malignant carcinoids and poorly differentiated neuroendocrine carcinomas (PNECs), whose clinical behavior is different. Currently, clinical outcomes and standard chemotherapy for NETs of the stomach remain unclear. We conducted a retrospective review of histopathologically confirmed NETs of the stomach at our hospital between January 2000 and August 2006. Thirty-seven NETs were identified. Fifteen patients had carcinoids while 22 had PNECs. Among the carcinoid patients, 7 underwent endoscopic mucosal resection and 5 had gastrectomy as first-line treatment. Three patients were observed without intervention. All patients were alive after an average follow-up period of 27 months. Among the 22 PNEC patients, 3 had no metastasis, 11 had regional lymph node metastasis, and 8 had distant metastasis. Eight of 14 patients relapsed at a median of 177 days (range 120-1459 days) after curative surgery. Twelve patients with metastatic or recurrent disease received palliative cisplatin plus irinotecan chemotherapy. The response rate was 75%, the median progression-free survival time was 212 days, and median survival time was 679 days. Gastric PNEC patients with distant metastasis had poor outcomes. Regimens containing cisplatin plus irinotecan produced a good response in gastric PNEC.