Triple-negative breast cancer is cancer that is estrogen-receptor-negative, progesterone-receptor-negative, and HER2-negative. Triple-negative breast cancer is less common than other types of breast cancer. Triple-negative breast cancer tends to be more aggressive than hormone-receptor-positive breast cancer and more resistant to the treatment options available.
Hormonal therapy medicines and HER2 targeted therapy medicines such as Herceptin (chemical name: trastuzumab) and Tykerb (chemical name: lapatinib) usually don't work on triple-negative breast cancer.
Another targeted therapy medicine, Avastin (chemical name: bevacizumab), and the chemotherapy Taxol (chemical name: paclitaxel) are sometimes used together to treat metastatic breast cancer, including triple-negative metastatic cancer. Metastatic breast cancer is cancer that has spread to areas of the body away from the breast, such as the bones or liver. Using Avastin to treat metastatic breast cancer is currently approved by the U.S. Food and Drug Administration (FDA) for women who haven't already been treated with chemotherapy.
A German study has found that some women diagnosed with triple-negative metastatic breast cancer who were treated with the Avastin and Taxol benefited from the treatment. Still, the women diagnosed with triple-negative metastatic breast cancer didn't get as much benefit from the Avastin-Taxol combination as women diagnosed with metastatic breast cancer that wasn't triple-negative.
The results were presented at the September 2011 European Multidisciplinary Cancer Conference (ECCO-ESMO).
From a larger study looking at using Avastin and Taxol as the first treatment for metastatic breast cancer, the researchers focused on 154 women diagnosed with triple-negative metastatic breast cancer. The researchers compared the outcomes of the women diagnosed with triple-negative cancer to the outcomes of women diagnosed with cancer that wasn't triple-negative.
Overall, 51% of the women diagnosed with triple-negative cancer had some response to the treatment compared to 65% of the women diagnosed with cancer that wasn't triple-negative.
The length of time that the women lived without the cancer growing (progression-free survival) was about 8 months for women diagnosed with triple-negative cancer compared to 10.1 months for women diagnosed with cancer that wasn't triple-negative.
The length of time the women lived with or without the cancer growing (overall survival) was about 16 months for the women diagnosed with triple-negative cancer compared to 22.9 months for the women diagnosed with cancer that wasn't triple-negative.
Both Avastin and Taxol can cause bothersome and sometimes serious side effects. Side effects were about the same in both groups of women.
Since the beginning of 2011, the FDA has been considering removing the breast cancer indication for Avastin; a final decision is expected by the end of 2011.
In June 2011, an FDA expert panel recommended that the breast cancer indication for Avastin be removed. The panel's recommendation came after 2 days of hearings that were part of an appeal by Genentech, the company that makes Avastin. In December 2010, another FDA expert panel made the same recommendation and Genentech had asked the FDA to reconsider.
Both FDA expert panels concluded that Avastin has not been shown to be safe and effective for treating metastatic breast cancer. The FDA experts noted that in studies combining Avastin with one of several chemotherapy medicines to treat metastatic breast cancer, the time before the cancer grew or spread (progression-free survival) increased only a little and Avastin also didn't increase overall survival. This means that women in the studies lived for about the same amount of time whether or not they got Avastin. This is why the FDA experts recommended that the breast cancer indication be withdrawn.
Many doctors believe that the benefits of Avastin for certain women diagnosed with metastatic breast cancer are worth the risks and cost of treatment. In July 2011, a committee of experts from the National Comprehensive Cancer Network (NCCN) -- an alliance of 21 of the world's leading cancer centers -- voted to continue to support the current approval of Avastin in combination with Taxol to treat metastatic, HER2-negative breast cancer that hasn't been treated with chemotherapy. Doctors can choose to use Avastin to treat metastatic breast cancer whether or not that particular use is officially approved by the FDA.
The FDA doesn't have to follow the recommendation of its expert panels, but it usually does. Margaret Hamburg, FDA commissioner, will make the final decision about withdrawing the breast cancer indication for Avastin.
An FDA decision to withdraw the Avastin breast cancer indication will not affect the approvals of Avastin to treat advanced cancers of the lung, colon, and rectum. Still, it would make it less likely that insurers will pay for Avastin to treat breast cancer. Even before the FDA decision, a number of U.S. health insurance companies already have decided not to cover the cost of Avastin treatment for breast cancer. The insurers will continue to pay for Avastin to treat the other cancers it's approved to treat.
Encouragingly, the day after the June 2011 FDA expert panel's recommendation, a spokesperson for Medicare announced that even if the Avastin breast cancer indication is removed, Medicare will continue to pay for Avastin to treat metastatic breast cancer. Medicare's announcement is important because many insurers follow Medicare's payment policies. Medicare and insurance companies often pay for treatments prescribed by doctors for a condition even if the treatment isn't FDA-approved for that specific use. The NCCN's continued support for Avastin to treat metastatic breast cancer also should make it more likely that many insurers will continue to pay for it even if the FDA removes the breast cancer indication.
If you've been diagnosed with triple-negative metastatic breast cancer, you and your doctor will develop a treatment plan that may include Avastin in combination with chemotherapy. Or your treatment plan already may include Avastin. This study suggests that Avastin could be beneficial for you.
If you're already getting Avastin and are responding to treatment, you may want to ask your doctor about both the FDA and the NCCN experts' recommendations. It's likely that your doctor will recommend that you stick with your treatment plan unless it stops being effective or unacceptable side effects develop.
Stay tuned to Breastcancer.org Research News for more information about the final FDA decision on Avastin.