Background: Neuroendocrine tumors (NETs) of the diffuse neuroendocrine cell system often present a considerable diagnostic and therapeutic challenge.
Methods: We have reviewed the literature on NET treatment between 1979 and 2008 (PubMed search: carcinoid or neuroendocrine tumor/tumour + treatment or management), and summarized current therapeutic options and recommendations.
Results: The majority of tumors are diagnosed at a stage that the only curative treatment, radical surgical intervention, is no longer an option. Biotherapy with somatostatin analogs is currently the most efficient treatment to achieve palliation. The interferon class of agents may have a role in selected individuals but substantial adverse events often limit their use. Conventional chemotherapy has minimal efficacy but may have some utility in undifferentiated or highly proliferating neuroendocrine carcinomas and pancreatic NETs. Hepatic metastases, depending on size, location and number, may be amenable to surgical resection, embolization or radio-frequency ablation. Peptide receptor targeted radiotherapy may lead to reduction in tumor size but in most circumstances has a tumor-stabilizing effect. A variety of antiangiogenesis and growth factor-targeted agents have been evaluated but to date the results have failed to meet expectations. Thus, long-acting somatostatin analogs remain the only effective pharmacotherapeutic option that improves symptomatology and quality of life with minimal adverse effects.