Oct. 5, 2011 -- For women with certain kinds of aggressive breast tumors, treatment has often come with a significant trade-off: The drugs that kill their cancer can sometimes permanently damage the heart.
"Those are patients, many of whom are going to be cured of their breast cancer, but now they've got symptomatic heart failure. And that's typically a long-term problem," says Amelia Zelnak, MD, a breast oncologist and assistant professor of hematology and oncology at Emory University's Winship Cancer Institute in Atlanta.
Now a new study shows that a shorter, less toxic chemotherapy regimen that includes the drug Herceptin appears to be just as effective in women with HER-2 positive breast cancer as using a standard three-drug therapy with Herceptin, a strategy that can be harder on the heart.
Zelnak says the study, which has been presented at several large cancer conferences, has already changed clinical practice. She says many doctors have begun offering the less toxic combination along with Herceptin as "one of our standards of care," particularly for women who have a low risk of recurrence. She was not involved in the research.
About one in five women with breast cancer test positive for a protein called HER-2. HER-2 spurs the growth of cancer cells, making these types of tumors particularly quick to spread.
Previous studies have shown that the drug Herceptin, which directly interferes with a cell's ability to be stimulated by the HER-2 protein, can slow or stop the growth of these cancers when they have spread beyond the breast.
As effective as it can be, Herceptin can also cause serious side effects, including damage to the heart muscle that can lead to heart failure. It can also cause serious and life-threatening breathing problems.
For that reason, doctors have been unsure whether Herceptin is safe enough to use in women with early-stage cancers.
The new study, which is published in the New England Journal of Medicine, is one of four large clinical trials designed to see if the benefits of Herceptin might outweigh the risks if the drug was used earlier in the course of cancer treatment.
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.