Treatment of gastroenteropancreatic neuroendocrine tumours with octreotide LAR

BACKGROUND: Octreotide long acting repeteable (LAR) is a new somatostatin analogue whose activity lasts 28 days. AIM: To assess its therapeutic efficacy, tolerability, and safety in patients with gastroenteropancreatic neuroendocrine tumours. METHODS: A total of 16 patients were studied; 10 patients with carcinoid tumours, three with non-functioning pancreatic tumours, two with Zollinger-Ellison syndrome associated with multiple endocrine neoplasia type 1, and one with glucagonoma were studied. Octreotide LAR was administered intramuscularly at a dose of 20 mg every 28 days for a mean of 10.7 months (range 6-15 months). RESULTS: In carcinoid tumour patients, octreotide LAR normalized bowel movements in nine out of 10 cases, and flushing episodes disappeared in seven out of eight cases. Even in the remaining six patients the symptoms disappeared. In carcinoid tumour patients, urinary 5-hydroxyindoleacetic acid decreased significantly. In the two patients with Zollinger-Ellison syndrome/multiple endocrine neoplasma type 1 and in the patient with glucagonoma, serum gastrin and plasma glucagon, respectively, decreased considerably. Tumour size remained unchanged in 14 out of 16 patients, and increased in the remaining two. No side-effects were observed. CONCLUSIONS: Octreotide LAR appears to have a good therapeutic efficacy, tolerability and safety in the treatment of neuroendocrine tumours. Its effects are similar to those of octreotide and lanreotide. However, because it only needs to be administered once every 28 days, it is preferable in clinical practice.