HOUSTON The first study to look at "real world" use of Herceptin in advanced breast cancer patients found a higher incidence of cardiac toxicity − 28 percent of patients treated − than clinical trials of the drug have reported to date, but also concluded that the majority of this heart damage could be reversed with treatment.
The study, published online August 14 in the Journal of Clinical Oncology, concludes that use of Herceptin in patients with metastatic breast cancer "is an acceptable risk," says the study's lead author, Francisco J. Esteva, M.D., Ph.D., an associate professor in the Department of Breast Medical Oncology at The University of Texas M. D. Anderson Cancer Center.
Herceptin, also known as trastuzumab, was approved for use in 1998 for women whose advanced breast cancer is HER2-positive. Approximately 30 percent of metastatic breast cancer cells produce an excess amount of the HER2 growth protein on their surface, which makes the cancer more aggressive. Herceptin is a monoclonal antibody that latches on to these proteins and inhibits tumor growth.
Other clinical trials testing Herceptin in combination with chemotherapy have found that between 10-26 percent of patients experienced cardiac toxicity, depending on the treatment protocol. That led to an FDA warning in 2003 that Herceptin use can result in congestive heart failure, leading to inability to pump enough blood throughout the body, or dysfunction in the heart's ventricle chamber, which pumps blood out of the heart.
According to Esteva, before this study, no one had looked at what happened to patients treated in a clinic, outside of an organized trial, after they used Herceptin for at least a year. "We often give it for several years if patients are responding to the treatment, so we set out to quantify the risks," he says.
The study followed 173 patients with metastatic breast cancer treated at M. D. Anderson. Patients were enrolled in t
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Contact: Laura Sussman
lsussman@mdanderson.org
713-745-2457
University of Texas M. D. Anderson Cancer Center
14-Aug-2006