Vascular endothelial growth factor activity after switching of bisphosphonate treatment for metastatic breast cancer
- Dr M Clemons, Medical Oncology, Princess Margaret Hospital (5-205), 610 University Avenue, Toronto, ON M5G 2M9, Canada; mark.clemons{at}uhn.on.ca
- Accepted 18 December 2008
Abstract
Background: Recent data have shown a fall in vascular endothelial growth factor (VEGF) concentrations after bisphosphonate (BP) treatment in BP-naïve patients. It has therefore been proposed that BPs may have in vivo anti-VEGF effects.
Aims: To explore whether VEGF concentrations change after administration of a more potent BP in patients receiving long-term BP treatment.
Methods: 31 patients with breast cancer who had progressive metastatic bone disease despite treatment with early-generation BPs were switched to zoledronic acid. Serum VEGF concentrations were measured at baseline, and weeks 1, 2, 3, 4, 8 and 12.
Results: VEGF concentration per platelet count did not change significantly at any time during the 12 weeks after treatment with zoledronic acid.
Conclusions: Switching to zoledronic acid did not suppress circulating serum VEGF concentrations in BP-pretreated patients. Novel approaches to assess the effect of BPs on the bone milieu may provide further insight into the possible antiangiogenic properties of BPs.
Footnotes
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Competing interests: None.
