Gastroenteropancreatic neuroectoderm tumor

The majority of gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) are diagnosed at a non-resectable stage due to non-specific clinical syndromes, late manifestations from mass effects, or incidental detection of a clinically silent disease. Management strategies include curative or cytoreduction surgery, imaging-guided intervention, chemotherapy, immunotherapy, and radionuclide therapies. In this step-by-step review, we provide a structured approach for standardized reading and reporting of medical imaging studies covering content and terminology...

PURPOSE OF REVIEW: Gastroenteropancreatic neuroendocrine tumors (GEP NETs) are relatively rare neoplasias arising from the embryonic neural crest, neuroectoderm and endoderm. GEP NETs occur either sporadically or as part of endocrine tumor susceptibility syndromes such as multiple endocrine neoplasia type 1 (MEN1), von Hippel Lindau (VHL) syndrome, neurofibromatosis (NF-1), and possibly tuberous sclerosis (TSC). The overall incidence of GEP NETs shows a significant increase over the past three decades...

INTRODUCTION: Receptor radionuclide therapy is a promising treatment modality for patients with neuroendocrine tumors for whom alternative treatments are limited. The aim of this study was to investigate the incidence of hormonal crises after therapy with the radiolabeled somatostatin analogue [(177)Lu-DOTA(0),Tyr(3)]octreotate ((177)Lu-octreotate). MATERIALS AND METHODS: All (177)Lu-octreotate treatments between January 2000 and January 2007 were investigated. Four hundred seventy-six patients with gastroenteropancreatic neuroendocrine tumors and three patients with metastatic pheochromocytoma were included for analysis...

The BRAF gene, one of the human isoforms of RAF, is activated by ras, leading to cooperative effects in cells responsive to growth factor signals. We studied the frequency of BRAF and k-ras-2 mutations in primary neuroendocrine gastroenteropancreatic (GEP) tumors. Mutation analysis of the BRAF and k-ras-2 genes was performed in 40 primary neuroendocrine tumors of the GEP system. The expression of extracellular signaling-related kinase (ERK) 1/2, an important downstream point of convergence in the ras-RAF-mitogen-activated protein-ERK pathway was analyzed immunohistochemically...

Functional gastroenteropancreatic tumors express all 5 somatostatin receptor subtypes (sst) in different quantities. Octreotide and lanreotide treat patients with these tumors by binding preferentially to sst2 and, to a lesser extent, to sst3 and sst5 receptors, thereby controlling prominent symptoms caused by hormone hypersecretion (diarrhea and flushing). Although symptoms initially improve in most patients, a loss of response occurs in about 50% during continuous treatment. The functional activity at sst receptors of SOM230, a new multiligand somatostatin analog, has been described and compared with that of somatostatin (SRIF-14) and octreotide...