© 2005-2012 American Society of Clinical Oncology (ASCO). All rights reserved worldwide.
The study: Researchers looked at adding the targeted therapy bevacizumab (Avastin) to chemotherapy with docetaxel (Taxotere) for women newly diagnosed with locally advanced or metastatic breast cancer (breast cancer that has spread outside of the breast and nearby lymph nodes). Targeted therapy is a treatment that targets faulty genes or proteins that contribute to cancer growth and development. Bevacizumab blocks angiogenesis (the formation of new blood vessels), which is needed for tumor growth and spread. Paclitaxel (Taxol), a drug similar to docetaxel, is already approved in combination with bevacizumab by the U.S. Food and Drug Administration for the treatment of newly diagnosed metastatic breast cancer.
In this study, 736 women received treatment with either docetaxel alone, a higher dose of bevacizumab plus docetaxel, or a lower dose of bevacizumab plus docetaxel. The higher dose of bevacizumab is the standard established in previous breast cancer studies, and the lower dose is the standard used for colorectal cancer treatment.
The results: After approximately 11 months, women who received the lower dose of bevacizumab were 21% less likely to have their breast cancer grow or spread, and women who received the higher dose of bevacizumab were 28% less likely to have their breast cancer grow or spread, compared with the women who received only docetaxel. Also, this study showed that the tumors shrank in 44% of women who received docetaxel alone, compared with 55% of women who received the lower dose of bevacizumab, and 63% of women who received the higher dose of bevacizumab. Because of the small size of the study, researchers were not able to compare the higher and lower doses.
About three-fourths (75%) of women taking either dose of bevacizumab experienced severe side effects, compared with 67% of women who received docetaxel alone. Although most side effects were from the chemotherapy, the most common side effect of bevacizumab was high blood pressure, which is treatable with medication. Severe bowel perforation (a hole in the intestinal wall), a side effect seen in other bevacizumab studies, occurred in few patients.
What this means for patients
“This study shows that the use of an anti-angiogenic drug to treat breast cancer is effective when combined with either docetaxel or paclitaxel and does not greatly increase the side effects,” said lead author David Miles, MD, Professor and Medical Oncologist at the Mount Vernon Cancer Centre in England. Women with advanced breast cancer should talk with their doctor about this and other treatment options.
What to ask the doctor
- What is the stage of my breast cancer?
- What are my treatment options?
- What are the short-term and long-term side effects of this treatment?
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