THURSDAY, Nov. 2, 2006 (HealthDay News) -- For women with early-stage breast cancer, adding the anthracycline drug epirubicin to the standard chemo "cocktail" is superior to using the cocktail alone, British researchers report.
As reported in the Nov. 2 New England Journal of Medicine, an analysis of two trials shows that the addition of epirubicin provides a 30 percent reduction in the risk of relapse and death, said lead researcher Dr. Christopher J. Poole, Macmillan Senior Lecturer in Medical Oncology at the University of Birmingham.
The study is expected to have more of an impact in Europe and elsewhere, since epirubicin is more commonly used overseas than in the United States or Canada, said Dr. Mark Levine, a professor of clinical epidemiology and biostatistics and oncology at McMaster University in Hamilton, Ontario.
Len Lichtenfeld, deputy chief medical officer for the American Cancer Society, agreed with Levine that the findings aren't likely to change the choice of treatments used in the United States.
North American patients often do receive a standard drug "cocktail," dubbed CMF because of its three components -- cyclophosphamide, methotrexate and fluorouracil.
"Several anthracycline-containing regimens are currently considered to be standard adjuvant treatment options available to women with primary breast cancer," Lichtenfeld explained. The findings don't mean the regimen used is the only one or the best, he added.
"This trial contributes to our knowledge of how to combine CMF and epirubicin in sequence," said Levine, who co-authored an editorial accompanying the report.
So, he said, "the [study's] take-home message depends on where you live. If you're in the U.S. or Canada, this trial doesn't really change anything." That's because the more popular chemotherapy regimens used in both those countries involve other drugs, not epirubicin, added on to the cocktail, he said.
In their study, the British group analyzed data from the National Epirubicin Adjuvant Trial (NEAT), begun in 1994, as well as the BR9601 Trial, begun in 1995. Funding for both came from Pfizer (then Pharmacia), which makes epirubicin, as well as government agencies.
The goal of both trials was the same: to determine the effectiveness of a group of chemo drugs called anthracyclines, such as epirubicin, as adjuvant treatment for early breast cancer.
Poole put the trials in perspective.
"One of the most significant advances in the treatment of breast cancer over the last 25 or 30 years has been in the development of adjuvant chemotherapy [given after other treatments, such as surgery] for women with early-stage disease to address the risk of microscopic metastatic spread of tumor," he said.
By the mid-70s, CMF was regarded as the "industry standard," Poole said. "And in the 1980s, the research focus changed to improving its efficacy by adding or substituting new drugs."
In the NEAT trial, more than 2,000 patients were assigned, randomly, to the epirubicin-plus-CMF treatment or just CMF. In the BR9601 trial, 374 patients were assigned to epirubicin plus a modified CMF treatment or just a modified CMF treatment.
Median follow-up was 48 months. At two years, the relapse-free survival was 91 percent in the combined groups from both trials vs. 85 percent in the CMF alone group. At five years, the overall survival was 82 percent of the combined group and 75 percent of the CMF-only group.
Adverse side effects were higher in the combination treatment group, Poole found. For instance, more patients in the NEAT trial group that got CMF plus epirubicin reported severe hair loss, nausea, vomiting and constipation.
Epirubicin has been associated with serious side effects, including treatment-related leukemias. The follow-up period was too brief to assess the incidence of secondary leukemias, the researchers wrote, and so far the trials have yielded just one case of leukemia.
According to Levine, the new study is not the first trial to show that regimens that contain epirubicin are better than CMF alone for patients with early breast cancer, but it helps confirm prior data.
To learn more about chemotherapy, visit the American Cancer Society.