Long-term follow-up of two patients with metastatic neuroendocrine tumours treated with octreotide.

Two patients are described with metastatic neuroendocrine tumours of the pancreas head and region of Vater. After surgery, administration of the long-acting somatostatin analogue octreotide was started. In the first patient we found an IgG-lambda paraproteinaemia and a parathyroid hormone-related protein (PTHrP) driven hypercalcaemia. By increasing the dose of octreotide the paraproteinaemia disappeared. In the second patient with a metastasized somatostatin producing neuroendocrine tumour, octreotide showed a long-term stabilizing effect on symptoms and progression of disease. The role of octreotide in the induction of changes in biological behaviour of malignant neuroendocrine cells is discussed.