Endocrine Abstracts

Background: Serum biomarkers which correlate with pituitary tumour growth would be valuable in the treatment and follow-up of patients with pituitary adenomas, particularly non-functioning adenomas. Vascular Endothelial Growth Factor (VEGF) mRNA is upregulated in almost all tumours, whereas matrix metalloproteinases 2 and 9 (MMP 2 and 9) have been demonstrated to be important in tumour vascularisation and invasion, particularly in prolactinomas.

Aim: The objective of this study was to investigate VEGF, MMP 2 and MMP 9 levels before and after pituitary surgery in both patients with acromegaly and non-functioning pituitary adenomas. This would help ascertain whether these biomarkers could be used to assess response to treatment.

Methods: Blood samples were obtained from 29 patients with acromegaly and 12 patients with a non-functioning pituitary adenoma an average of 84 days before and 101 days after surgery. Paired t-tests were used to compare VEGF, MMP 2 and MMP 9 levels before and after surgery.

Results: Mean VEGF levels (± SEM) before and after surgery respectively were 129.5±62 and 134.7±50 pg/ml in acromegaly, 100.1±10.7 and 107.7±14.5 pg/ml in non-functioning adenomas. Mean MMP 2 levels before and after surgery were 176.6±9.7 and 154.5±7.7 ng/ml in acromegaly, 178.8±14.7 and 176.5±10.8 ng/ml in non-functioning adenomas. Mean MMP 9 levels before and after surgery were 160.5±19.5 ng/ml and 186.3±23.3 ng/ml in acromegaly, 337±49.6 ng/ml and 369±50 ng/ml in non-functioning adenomas. No significant difference was seen between VEGF, MMP 2 or MMP 9 levels before or after surgery.

Conclusions: The serum levels of VEGF, MMP 2 and MMP 9 were not altered by debulking of pituitary adenomas, which suggests that these markers do not correlate with changes in tumour size or surgery.