Pamidronate induces modifications of circulating angiogenetic factors in cancer patients

Purpose: Recently, new experimental data suggested that, besides inhibiting osteoclasts, bisphosphonate may also have an antitumor effect. Antiangionetetic activity is one of the possible mechanisms of anticancer activity attributed to bisphosphonates. The purpose of this study was to evaluate the modifications in angiogenic cytokines levels after pamidronate infusion. Experimental Design: Twenty-five consecutive cancer patients with bone metastases treated monthly with disodium pamidronate infusion were evaluated prospectively for circulating levels of vascular endothelial growth factor (VEGF), gamma-IFN, interleukin (IL)-6, and IL-8 at different time points: just before and after 1, 2, and 7 days after pamidronate infusion. Results: Basal VEGF levels decreased significantly 1, 2, and 7 days after pamidronate infusion. gamma-IFN and IL-6 levels increased 1 day after the infusion but rapidly decreased after 2 days. Moreover, our data showed a statistically significant negative correlation between VEGF and gamma-IFN levels (P < 0.0001) and a positive correlation between VEGF and IL-8 (P = 0.04). Conclusions: This study confirms that pamidronate could have antiangiogenic properties through a significant and lasting decrease of VEGF serum levels.