Susumu Hijioka, Waki Hosoda, Chigusa Morizane, Nobumasa Mizuno, Kazuo Hara, Takuji Okusaka
Pancreatic neuroendocrine carcinoma (panNEC; pancreatic neuroendocrine neoplasm NEN-G3) is expected to be divided into neuroendocrine tumor-G3 and neuroendocrine carcinoma-G3 in the World Health Organization 2017 classification of tumors of endocrine organs. The distinction is clinically important because the response to chemotherapy differs between the two. Evidence is accumulating on the molecular features of NET-G3, which supports the view that NET-G3 is more closely related to well-differentiated NET. Several molecular markers can be useful in predicting the effectiveness of platinum-based chemotherapies, including high Ki67 labeling index, loss of Rb expression, or KRAS mutation. However, appropriate chemotherapy for NET-G3 remains unclear. Appropriate classification of NET-G3/NEC-G3 and the adequacy of standard treatments depending on this classification are expected in the future with the accumulation of further cases.