Molecular targeted therapies in the treatment of gastroenteropancreatic neuroendocrine tumors

Gastroenteropancreatic neuroendocrine tumors (GEPNETs) are rare neoplasms that require a multidisciplinary approach for an optimal management. The traditional cytotoxic agents are of limited efficacy in the treatment of these tumors. A better understanding of the molecular pathways that characterize tumor growth has provided novel targets in cancer treatment. Several proteins have been implicated as having a crucial role in GEPNETs. Several proangiogenic molecules are overexpressed in GEPNETs including vascular endothelial growth factor (VEGF) and its receptors, and related signaling pathway components such as epidermal growth factor receptor (EGFR), insulin growth factor-I receptor (IGF-IR) and PI3K-AKT-mTOR pathway. In this article we aim to review the recent development of the main molecules that target these proteins and have showed promising activity in the treatment of GEPNETs.