American Cancer Society answered:
Tumors need to develop and maintain new blood vessels in order to grow. Drugs that target new blood vessels (angiogenesis) are proving to be helpful against a variety of cancers, including breast cancer.
Bevacizumab (Avastin®) is a monoclonal antibody that may be used in patients with metastatic breast cancer. This antibody is directed against vascular endothelial growth factor, a protein that helps tumors form new blood vessels.
Bevacizumab is given by intravenous (IV) infusion. It is most often used in combination with the chemotherapy drug paclitaxel (Taxol). It has also been studied for use against breast cancer in combination with capecitabine (Xeloda).
Rare, but possibly serious side effects include bleeding, holes forming in the colon (requiring surgery to correct), and slow wound healing.
More common side effects include high blood pressure, tiredness, blood clots, low white blood cell counts, headaches, mouth sores, loss of appetite, and diarrhea. High blood pressure is very common, so it very important that your doctor watches your blood pressure carefully during treatment.
Bevacizumab was first approved by the Food and Drug Administration (FDA) as part of the treatment for metastatic breast cancer in 2008. The approval was based on a study in which the women that received bevacizumab with chemo had a longer time without their cancers growing than the women who received chemo alone. New study results that were presented at a recent FDA meeting (in July, 2010) did not show a real benefit for the women receiving bevacizumab as a part of their treatment. At this time, the role of this drug in treating breast cancer is not clear.Tumors need to develop and maintain new blood vessels in order to grow. Drugs that target new blood vessels (angiogenesis) are proving to be helpful against a variety of cancers, including breast cancer. Bevacizumab (Avastin®) is a monoclonal... More