Models of gastroenteropancreatic neuroendocrine neoplasms - Current status and future directions.

Gastroenteropancreatic (GEP) neuroendocrine neoplasms (NEN) are a rare, heterogeneous group of tumors that originate from the endocrine system of the gastrointestinal tract and pancreas. GEP-NEN are subdivided according to their differentiation into well differentiated gastroenteropancreatic neuroendocrine tumors (NET) and poorly differentiated gastroenteropancreatic neuroendocrine carcinomas (NEC). Since GEP-NEN represent rare diseases only limited data from large prospective, randomized clinical trials are available, and recommendations for treatment of GEP-NEN are in part based on data from retrospective analyses or case series. In this context, tractable disease models that reflect the situation in humans and allow to recapitulate the different clinical aspects and diseases stages of GEP-NET or GEP-NEC are urgently needed. In this review, we highlight available data on mouse models for gastroenteropancreatic neuroendocrine neoplasia. We discuss how these models reflect tumor biology of human disease and whether these models could serve as a tool for understanding the pathogenesis of GEP-NEN, for disease modeling and pharmacosensitivity assays facilitating prediction of treatment response in patients. In addition, open issues applicable for future developments will be discussed. The Author(s). Published by S. Karger AG, Basel.