Onkológia 4/2006

SYSTEMIC THERAPY OF NEUROENDOCRINE TUMORS

Gastroenteropancreatic neuroendocrine tumors (NET-s) constitute a heterogeneous group of neoplasms that are often associated with typical symptoms due to excessive and uncontrolled release of hormones. NET-s are rare tumours and may present at different disease stages with either hormonal or hormone related symptoms/syndromes or without hormonal excretion. They may occur either sporadically or as a part of hereditary syndromes. Because these tumors are usually slow growing, surgery is the cornerstone of treatment. however, these rare tumors can present with rapid progression that requires aggressive systemic therapy or as diffuse metastatic disease not amenable to surgical palliation. For most patients, medical approaches are necessary at some point in the course of their disease, especially since most tumors are at an advanced stage at the time of diagnosis. Most gastroenteropancreatic neuroendocrine tumors express high levels of somatostatin receptors, which are bound by somatostatin or its synthetic analogues. Somatostatin analogues have been the mainstay of symptomatic management of patients with NETs for two decades with the main mechanism of action being inhibition of peptide release. These agents or the other therapies, such as interferon, chemotherapy or radioisotopes are therefore used frequently to control hormone-related symptoms and for some patients, the growth of the disease itself. Evidence base for interferon use is perhaps less clear.

Keywords: Neuroendocrine tumours, carcinoid, surgery, chemotherapy, somatostatin analogues, octreotide, lanreotide, interferon.