Gastroenteropancreatic Neuroendocrine Tumors: Update on Therapeutics

Abstract

To review the available literature addressing the treatment of pancreatic neuroendocrine tumors (PNETs) and carcinoid tumors. Relevant literature was identified by a PubMed search (January 1977-December 2011) of English-language literature using the terms gastroenteropancreatic neuroendocrine tumor, pancreatic neuroendocrine, carcinoid, and pancreatic islet cell tumor. All published studies and abstracts, as well as relevant consensus guidelines, evaluating the current literature about PNETs and carcinoid tumors were included. Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a genetically diverse group of complex malignancies with varying biological and clinical courses. Historically believed to be rare, recent epidemiologic data suggest their incidence is rising. Two of the most commonly diagnosed GEP-NETs are PNETs and carcinoid tumors. Both subtypes are well-differentiated tumors and present as low or intermediate grade. The systemic manifestations of PNETs and carcinoid tumors are diverse and are related to the secretion of affected hormones and biogenic amines. Surgical resection of localized disease remains the only curative option. However, the utility of this approach is limited because most patients are diagnosed with advanced disease. Recent advances have led to an improvement in outcomes in patients with PNETs and carcinoid tumors. This review describes traditional therapies as well as emerging strategies being investigated to help manage these cancers. Treatment of poorly differentiated GEP-NETs is beyond the scope of this review. The advent of new therapies for PNETs and carcinoid tumors has introduced a paradigm shift in the management of this heterogeneous malignancy.