Endocrine tumours of the gastrointestinal tract. Biotherapy for metastatic endocrine tumours.

Somatostatin analogues have been the mainstay of symptomatic management of patients with neuroendocrine tumours (NETs) for two decades with the main mechanism of action being inhibition of peptide release. Evidence base for interferon use is perhaps less clear. It may contribute to symptom control by abrogating peptide release, and there is some evidence that it has an anti-proliferative action. Combination of somatostatin analogues and interferon provides symptom control, mainly by effecting a reduction in the amount of circulating, physiologically active, peptide hormones. Treatment can also provide disease stabilisation in a proportion of patients. In a minority of patients treatment may lead to partial response.