Endocrine Abstracts

BACKGROUND: Antiangiogenic effects have been demonstrated with currently available somatostatin analogues. The mechanism remains unclear, although some studies suggest inhibition of the pro-angiogenic tumour vascular endothelial growth factor (VEGF) production.

OBJECTIVE: To determine whether pre-operative Lanreotide (LAN) in patients with acromegaly influences circulating VEGF.

PATIENTS AND METHODS: Serum samples from six acromegalic patients were taken at 0, 8 and 16 weeks of treatment with LAN prior to surgery, and at 6 and 16 weeks after surgery off treatment. LAN 30 miligrams was administered two weekly and increased to weekly if at week 8 the mean GH was greater than 5 miliunits per litre. VEGF serum levels were determined by ELISA and correlated with mean GH and IGF-I levels.

RESULTS: Despite a weak correlation between suppression of VEGF and GH levels (r=0.28) and suppression of VEGF and IGF-I levels (r=0.36) during treatment with LAN, there was no significant difference between circulating VEGF pre-treatment, on LAN, and following surgery. Mean GH less than 5 miliunits per litre was achieved in 5/6 patients on LAN therapy.

CONCLUSION: Treatment with LAN in acromegalic patients prior to surgery did not decrease VEGF serum levels. Since a tendency to suppression with treatment and an increase with treatment cessation was observed, larger studies are required, to determine whether LAN leads to reduction of the pro-angiogenic VEGF in patients with GH secreting adenomas.