Abstract
Background: To evaluate the modifications of circulating angiogenic factors, metalloproteinases and acute-phase cytokines after the first single zoledronic acid (ZA) intravenous infusion. Experimental Design: Eighteen consecutive breast cancer patients with bone metastases were evaluated for circulating levels of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), metalloproteinase 1 (MMP-1), metalloproteinase 2 (MMP-2), interleukins 1β, 6 and 8 (IL-1β, IL-6, IL-8), interferon γ, tumor necrosis factor α (TNF-α) and transforming growth factor β1 just before and 2 and 7 days after ZA infusion. Results: The MMP-2 basal value showed a statisticallysignificant decrease 48 h after ZA (p = 0.01), being at 7 days higher than the day 2 value (p = 0.03). The VEGF basal value showed a statisticallysignificant decrease 48 h after ZA infusion (p = 0.03), increasing above the basal level at 7 days (p = 0.07). The bFGF basal level almost significantly decreased 2 days after infusion (p = 0.06), being at 7 days higher than the basal value (p = 0.09). Comparing the day 2 values with basal ones, the linear regression model showed a significantpositive correlation between IL-8 and bFGF (p = 0.02), IL-8 and TNF-α (p < 0.0001), bFGF and TNF-α (p = 0.01), MMP-1 and TNF-α (p = 0.02). Conclusions: ZA could exert an antiangiogenic activity and inhibition of tumor cell bone invasiveness by a transient reduction of VEGF, bFGF and MMP-2 circulating levels after infusion.