Bevacizumab: the first anti-angiogenic agent approved for the treatment of metastatic breast cancer

The complexity of options available for breast cancer treatment dictates that therapeutic decisions are made on an individualised basis. Subsets of tumours defined in part by steroid hormone receptor and human epidermal growth factor receptor 2 (HER2) status have been identified. Endocrine therapy and the HER2- targeted antibody, trastuzumab, have improved the prognosis for those patients whose tumours express the respective targets. Similar therapeutic advances for patients whose tumours lack these markers have not occurred in the metastatic setting. Tumour growth and proliferation is known to be reliant on angiogenesis, and vascular endothelial growth factor (VEGF) is a key pro-angiogenic mediator. Bevacizumab, a humanised anti-VEGF monoclonal antibody, is the first antiangiogenic agent to demonstrate clinical benefit when combined with chemotherapy in metastatic breast cancer, providing a doubling of progression-free survival with a manageable safety profile. This supplement considers the development, mode of action, clinical data and future therapeutic use of this agent in breast cancer.