This analysis of three large studies found that Avastin (chemical name: bevacizumab) and chemotherapy improved the length of time women lived without newly diagnosed metastatic breast cancer growing by about 31% compared to chemotherapy alone. The results were reported at the 2010 European Breast Cancer Conference.
Metastatic breast cancer is cancer that has spread outside the breast to another part of the body.
Avastin is anti-angiogenesis targeted therapy. Avastin works by blocking the growth of new blood vessels that cancer cells depend on to grow and function. The vascular endothelial growth factor (VEGF) protein makes new blood vessels grow in cancer cells. Avastin blocks the VEGF protein.
Avastin is approved by the U.S. Food and Drug Administration to be used in combination with Taxol (chemical name: paclitaxel) to treat metastatic HER2-negative breast cancer that hasn't been treated with chemotherapy. Avastin also is used to treat advanced-stage lung, colon, and kidney cancer. Avastin is given intravenously.
The analysis is called a meta-analysis because it analyzes the results of several different studies. All the studies compared how metastatic breast cancer responded to chemotherapy with or without Avastin as the first treatment. Each study used different chemotherapy medicines. The combinations were:
- Taxol (chemical name: paclitaxel) alone, compared to Avastin and Taxol
- Taxotere (chemical name: docetaxel) alone, compared to Avastin and Taxotere
- An anthracycline chemotherapy medicine alone or a taxane chemotherapy medicine alone, compared to Avastin and an anthracycline or a taxane
- Adriamycin (chemical name: doxorubicin)
- Doxil (chemical name: doxorubicin)
- daunorubicin (brand names: Cerubidine, DaunoXome)
- Ellence (chemical name: epirubicin)
- mitoxantrone (brand name: Novantrone)
- Abraxane (chemical name: albumin-bound paclitaxel)
Almost 2,700 women diagnosed with metastatic breast cancer participated in the studies. None of the women had previously been treated for metastatic breast cancer.
Women who got Avastin and chemotherapy lived 21% to 40% longer (an average of 31% longer) without the cancer growing (called progression-free survival) compared to women who got only chemotherapy.
Women who got Avastin and chemotherapy also were 85% more likely to have a response to treatment compared to women who got only chemotherapy.
Overall survival (with or without the cancer growing) was 12% better in women who got Avastin and chemotherapy compared to women who got chemotherapy alone. This difference in overall survival wasn't significant, which means that it could have been due to chance and not because of the difference in treatment.
Common side effects of Avastin include high blood pressure, nosebleeds, and extra protein in the urine. Avastin also may cause weakness, pain, and diarrhea. Avastin may cause other serious side effects, including a higher risk of stroke or heart problems, kidney malfunction, and reduced white blood cell count. In the three studies, women who got Avastin were more likely to have high blood pressure, protein in the urine, heart problems, and nerve pain.
These results suggest adding Avastin to chemotherapy as the first treatment for metastatic breast cancer has some benefits. Still, some doctors believe that the benefits are small and may be outweighed by the risk of serious side effects from Avastin. Avastin also is expensive: treatment can cost $30,000 to $40,000 per month. Insurance coverage varies, but some people receiving Avastin may have to pay part of the cost.
If you've been diagnosed with metastatic breast cancer, together you and your doctor will develop a treatment plan that will likely include chemotherapy and possibly hormonal therapy and/or targeted therapy medicines such as Avastin. As you talk about your treatment, ask your doctor:
- the reasons for each treatment recommendation (including any combinations)
- the order and timing of each treatment
- the expected benefits, risks, and side effects of each treatment
With all the information, you and your doctor can decide on a treatment plan that makes the most sense for you and your unique situation.
Learn more about Avastin, how it works, and how it's used to treat advanced-stage breast cancer in the Breastcancer.org Targeted Therapies section.