[A case report of a well-differentiated neuroendocrine tumor in which sunitinib treatment resulted in stable disease].

A 52-year-old woman had a primary neuroendocrine tumor, Grade 2(NET G2)with multiple liver metastases and a mesenteric tumor. Since no drugs were approved for NET at that time in Japan, we treated her with sunitinib after approval by the Ethics Committee of Mie University Hospital and obtaining informed consent. Sunitinib was administered at a daily dose of 37.5mg/day, but the dose was reduced to 12.5mg/day because of thrombocytopenia(G3)and neutropenia(G3). CT revealed stable disease after 3 months of treatment, but disease progression was observed after 11 months. The non-hematological toxicity was hypertension(G3), which was controlled with antihypertensive agents. Although there are no previous reports of the treatment of well-differentiated NET with sunitinib in Japan, sunitinib may be effective against this disease.