Less Toxic Treatment for Aggressive Breast Cancers?
Newer Chemo Regimen, With Added Herceptin, May Be Less Damaging to the Heart
Adding Herceptin to Chemotherapy continued...
The study randomly assigned 3,222 women with early-stage HER-2 positive tumors to one of three treatment groups. The first group was given a standard cocktail of three chemotherapy drugs that all slow or stop the growth of rapidly dividing cells -- doxorubicin and cyclophosphamide, followed by docetaxel.
Doxorubicin is a type of drug called an anthracycline, and it's sold under the brand names Adriamycin, Doxil, and Rubex. Like Herceptin, doxorubicin can damage the heart. Using the two drugs together increases that danger.
The second group got the same three-drug regimen along with a year of Herceptin.
The third group was given docetaxel and a newer drug called carboplatin along with a year of Herceptin.
The study found that adding Herceptin increased the odds that a woman would still be alive and cancer-free more than five years after treatment. It didn't seem to matter whether she was on the standard, more toxic regimen or the newer, less toxic drugs.
Overall, 87% of the women on the standard, three-drug combination were still alive and 75% were cancer-free more than five years later, while 92% of the women were still alive and 84% were cancer-free when Herceptin was added to that treatment.
Of the women on the newer, two-drug regimen with added Herceptin, 91% were still alive and 81% were cancer-free more than five years later.
The differences between the two groups that got Herceptin were not statistically significant.
The benefit for Herceptin was seen whether tumors were small or large and even in women who had positive lymph nodes, indicating that their cancer had spread.
Fewer Side Effects
The biggest difference came when researchers looked at side effects patients experienced.
Patients on the newer, two-drug combination had less joint and muscle pain, less irritation and peeling of the skin and mucous membranes, and less vomiting. There were also fewer reports of low white blood cell counts in the group on the two-drug regimen.
Seven patients on the three-drug regimen developed leukemia, compared to one patient on the newer regimen, but that patient had received another drug, an agent linked with leukemia, outside the study to treat another cancer that arose after her breast cancer.