The breast cancer drug Herceptin prevents breast cancer from coming back in some women, new research shows.

Moreover, Herceptin works just as well with and without Adriamycin, a chemotherapy drug commonly used to treat breast cancer, says researcher Dennis Slamon, MD, PhD, director of clinical and translational research at UCLA’s Jonsson Comprehensive Cancer Center.

That’s important because when paired with Herceptin, Adriamycin can cause permanent heart damage, he says.

“The benefits of Herceptin are significant,” Slamon tells WebMD. “But when used with Adriamycin, we may be causing more problems that we are fixing."

“The new results tell us that by using Herceptin with chemotherapy regimens that do not include Adriamycin, we can get just as good results -- without causing potentially fatal heart problems,” he says.

The findings were presented at the San Antonio Breast Cancer Symposium.

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Safer for the Heart

The new findings come from a study of more than 3,200 women with early breast cancer who were HER2 positive. Herceptin, an antibody therapy, targets the HER2 protein, which plays a role in cell growth. These women tend to develop aggressive, faster growing tumors.

The participants in the study received one of three treatments:

The standard therapy of Adriamycin and Cytoxan followed by Taxotere. An experimental regimen of Adriamycin and Cytoxan followed by Taxotere and one year of Herceptin. An experimental regimen of Taxotere and Paraplatinwith one year of Herceptin.

The results showed that after three years, women who took either of the Herceptin-containing regimens were about one-third less likely to suffer a recurrence of breast cancer than those who took standard therapy.

Additionally, the risk of dying was reduced by a third or more in women taking Herceptin.

The researchers then looked at side effects in women taking the two Herceptin-containing treatments. They found that women who took Adriamycin were five times more likely to develop heart failure than those who did not take Adriamycin.

“There was also a doubling of loss of some heart function among the women in the Adriamycin group, and some developed leukemia, while none of the women on the non-Adriamycin arm did,” Slamon says.

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'Practice-Changing' Findings

Slamon says the findings are significant enough to change the way doctors treat women with early breast cancer who carry the HER2/neu gene, the gene that produces HER2.

“We should move Adriamycin out of this setting and reserve it for women with metastatic disease if they have run out of other options. The preferred treatment of choice is Herceptin in combination with a non-Adriamycin-containing regimen such as Taxotere and/or carboplatin,” he says.

There doesn’t seem to be much benefit to offering the Adriamycin-Herceptin combo to these women, says William Gradishar, MD, a breast cancer specialist at Northwestern University in Evanston, Ill.

“If we can use an alternative recipe with Herceptin and get the same results, there may not be any upside to using Adriamycin in women with the HER2/nue gene,” he tells WebMD.

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By Charlene Laino, reviewed by Brunilda Nazario, MD

SOURCES: San Antonio Breast Cancer Symposium, Dec. 14-17, 2006. Dennis Slamon, MD, PhD, director, clinical and translational research, UCLA’s Jonsson Comprehensive Cancer Center. William Gradishar, MD, Northwestern University, Evanston, Ill.