(RxWiki News) HER2-positive breast cancer is an aggressive disease that thankfully can be treated with targeted therapies. A new combination regimen was successful in keeping patients in a recent trial disease free.
A phase lll trial found that a combination of medications given after surgery was extremely effective in treating patients with HER2-positive breast cancer, which was likely to spread or return (recur).
Three years after receiving a combination of Taxotere (docetaxel), Paraplatin (carboplatin) and Herceptin (trastuzumab), 92 percent of patients with HER2-positive breast cancer were still alive with no evidence of the disease.
The researchers discovered that highly toxic chemotherapies, which have traditionally been used to treat this form of breast cancer, were unnecessary to achieve this success.
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Dennis J. Slamon, MD, PhD, director of clinical/translational research at the University of California, Los Angeles (UCLA) Jonsson Comprehensive Cancer Center, led this trial. Investigators were evaluating the effectiveness of adding Avastin (bevacizumab) to post-surgery combination regimens for treating HER2-positive breast cancer that had spread to the lymph nodes or was likely to recur.
HER2 stands for human epidermal growth factor receptor 2. It's a cell protein that encourages cancer cells to grow. HER2 plays a role in about 20 percent of invasive breast cancers.
This fast growing cancer has traditionally been treated with chemotherapy agents called anthracyclines, including Adriamycin (doxorubicin) and Ellence (epirubicin).
Dr. Slamon explained in a statement, “Unfortunately, the long-term side effects of anthracyclines in all groups include congestive heart failure and leukemia. We and others have previously shown that adding trastuzumab to anthracycline-based therapy in adjuvant disease [residual disease following surgery] increases this cardiac toxicity between three- to fivefold.”
For this study called the BETH ("bevacizumab and trastuzumab adjuvant therapy in HER2-positive breast cancer") trial, 3,509 patients with HER2-positive breast cancer were enrolled.
The largest group was comprised of 3,231 who were randomly assigned to receive the TCH (Taxoter, carboplatin and Herceptin) regimen alone or with bevacizumab (Avastin). The smaller group of 279 received the anthracycline epirubicin along with trastuzumab (Herceptin) with or without Avastin.
After 38 months of follow-up, the researchers found the disease-free (no evidence of disease) survival was 92 percent in both of the TCH groups. The disease-free survival of the group of patients who took the traditional chemotherapy, along with Herceptin, was 89 percent.
The addition of Avastin did not result in any benefits in any of the groups, the investigators learned.
“It is going to be difficult to develop treatment regimens that have even better response rates than that,” Dr. Slamon said. “While there is some small room for improvement, we now need to further concentrate on improving the safety of adjuvant treatment regimens."
The researchers plan to continue to follow the study members to evaluate long-term results of these therapies.
Results from the BETH trial were presented at the 2013 San Antonio Breast Cancer Symposium.
It should be noted that all research is considered preliminary before being published in a peer-reviewed journal.
This study was supported by funds from Roche/Genentech, the makers of Avastin and Herceptin. Dr. Slamon has served as an adviser to both companies in the past several years, including the time during which the study was conducted.