Medical Treatment of Gastroenteropancreatic (GEP) Neuroendocrine Tumors

Abstract

Neuroendocrine tumors (NETs) are a heterogeneous group of neoplasms that arise from the diffuse endocrine system present in various organs. These tumors are classified as functioning and nonfunctioning due to the presence of a specific syndrome determined by the production of some peptides and, due to the low incidence, they are considered rare. This landscape is going to change due to the steadily rising prevalence and incidence as reported by a recent SEER database analysis. The first aim of the treatment of patients with diagnosis of NETs is to cure, and this goal could be achieved by surgery. If patients are not suitable for surgery with curative intent, a medical management for symptom and disease is required. Somatostatin analogues are the backbone of the treatment of symptoms; a few years later after their introduction in clinical practice, the antiproliferative effects were demonstrated by two clinical trials. Significant clinical activity was also achieved with two different oral target therapies: everolimus (mTOR inhibitor) and sunitinib (multi-targeted receptor tyrosine kinase inhibitor). Chemotherapy maintains a significat role for the most aggressive variants such as neuroendocrine cancers (NECs). At last, the peptide receptor radiotherapy is an innovative therapeutic approach for somatostatin receptor-positive inoperable and metastatic NETs.