Phase II study of sunitinib in Japanese patients with unresectable or metastatic, well-differentiated pancreatic neuroendocrine tumor - Ito, T; Okusaka, T; Nishida, T; Yamao, K; Igarashi, H; Morizane, C; Kondo, S; Mizuno, N; Hara, K; Sawaki, A; Hashigaki, S; Kimura, N; Murakami, M; Ohki, E; Chao, R C; Imamura, M (Invest New Drugs, 2013)