Endocrine Abstracts

Neuroendocrine gastro-enteropancreatic tumors constitute a diverse group of malignant neoplasms with a common feature of hormone production and release. The incidence and prevalence have constantly increased over the last decades with an incidence of about 6/100 000 and a prevalence of 35/100 000 inhabitants. The majority of patients present a metastatic disease at diagnosis. The most common subtypes of GEP-NETs are small intestinal NETs (carcinoids) followed by pancreatic and rectal NETs. The diagnosis is based on histopathology verification of neuroendocrine features such as positive immunohistochemical staining for CgA, synaptophysin and NSE. The proliferation is determined by the antibody MIB-1 (Ki-67). The biochemical workup includes a general tumor marker such as CgA, which is complemented by peptides and amines related to clinical symptoms (i.e. u-5HIAA, gastrin, glucagon). Localisation procedure include standard radiology, such as CT/MRI, US and endoscopic US. The majority of GEP-NETs express somatostatin type 2 receptors, whereby staging and localisation can be performed by somatostatin receptor scintigraphy with 111Indium-DTPA-Octreotide as well as PET-scanning with 68Ga-DOTATATE. The treatment of neuroendocrine GEP tumors includes surgery as well as debulking procedures such as RFA, embolization (plain or radio-embolization). Peptide receptor radiotherapy is more and more applied using radioactive 177Lutetium-DOTATATE or 90Yttrium-DOTATOC. The medical treatment includes biotherapy such as somatostatin analogs, interferons but also cytotoxic agents, including streptozotocin, 5FU, cisplatinum, etoposide, temozolomide + capecitabine. Most recently pancreatic NETs have been successfully treated with tyrosine kinase inhibitors, sunitinib, as well as the mTOR inhibitor, everolimus (Afinitor). The treatment is based on tumor type, stage and grade. In the future a more personalized treatment will be developed, based on information from molecular genetics and tumor biology.

Declaration of interest: The author declares that there is a conflict of interest.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.