Section Review: Oncologic, Endocrine & Metabolic: Immunoneuroendocrine therapy for endocrine tumours: recent developments

Abstract

Immunoneuroendocrine therapy for endocrine tumours represents a therapeutic strategy capable of inhibiting endocrine cancer growth by acting simultaneously on both endocrine and immune mechanisms. This strategy is realised by the administration of cytokines able to induce both endocrine and immune effects and/or neurohor-mones with immunomodulating properties in addition to their neuroendocrine activity. In terms of their effects on endocrine tumours, interferon-α (IFNα) and interleukin-2 (IL-2) are the most investigated cytokines; the long-acting somatostatin analogue, octreotide, and the pineal hormone, melatonin (MLT), are the correspondingly most interesting neurohormones. At present, there are clinical data concerning the efficacy of IFN alone and octreotide alone, whereas only Imited data are available concerning the effects of IL-2 alone or IL-2 plus MLT. IFN alone and octreotide alone seem to be the most effective drugs in the control of the cell proliferation and clinical symptomatology, respectively, of gastroenteropancreatic (GEP) endocrine tumours. Moreover, their association would be expected to improve treatment efficacy further. On the contrary, the efficacy of IFN or octreotide in endocrine neoplasms other than GEP tumours, such as medullary thyroid carcinoma, phaeochromocytoma and adrenal cancers, remains to be established. IL-2 in association with MLT has been proven to induce objective tumour regressions in endocrine neoplasms previously unresponsive to standard therapies. IL-2 alone seems to be less effective. Future advances in the knowledge of immunoneuroendocrine interactions will allow us to improve the clinical results of immunoneuroendocrine therapy for endocrine tumours.