Study Released at ASCO Finds Longest Survival to Date for Stage 4 HER-2 Positive Breast Cancer
MAYWOOD, Ill. - Researchers using a new cocktail of cancer treatment drugs are reporting the best survival rate to date in patients with an aggressive type of advanced breast cancer.
Results were announced at the 2008 meeting of the American Society of Clinical Oncology (ASCO) in Chicago.
The study included 76 patients from 28 centers who had HER-2 positive breast cancer, in which the cancer had spread to distant sites such as bones, liver, lungs or brain. Their ages ranged from 33 to 78. The median age was 50.
Patients received trastuzumab (HerceptinÂ®) which targets HER-2 positive cancer cells, in combination with two chemotherapy drugs: docetaxel (TaxotereÂ®) and vinorelbine (NavelbineÂ®). Ninety-three percent of these patients survived for at least one year. The median time the spread of cancer was held in check was 21 months, and the median survival was 39 months. By comparison, in previous studies on similar patients, median survivals ranged from 18.4 months to 38 months, and the median length of time the cancer was held in check ranged from 3 months to 13.8 months.
"I think doctors will start to use this combination once they see these results," said Dr. Kathy Albain of Loyola University Medical Center, a co-author and member of the national leadership team that designed the study.Albain is a professor in the division of hematology/oncology, Department of Medicine at Loyola University Chicago Stritch School of Medicine.
HER2-positive breast cancer is a type of cancer that tests positive for a receptor on the surface of the cancer cell called HER2. This protein interacts with other proteins to promote the growth of cancer cells. HER2-positive breast cancers tend to be more aggressive than those that do not have HER2 on the surface of the cell.
Previously, doctors have combined the chemotherapy drugs docetaxel and vinorelbine. Doctors also have used either docetaxel or vinorelbine with trastuzumab. The new study marks the first time all three drugs have been used together, Albain said.
In the phase II study, 21 percent of patients went into complete remission for a period of time and 52 percent showed a partial response to the drugs.
Side effects included high blood sugar, low white blood cell count, fatigue and infections. But overall, the regimen was well tolerated, Albain said. The study regimen also included a self-administered daily shot to boost the white blood cell count and keep infection rates low.
Researchers are discussing plans for a larger follow-up study in which patients who receive the new drug regimen would be compared with a control group of patients who receive standard therapy.
The study was primarily funded by the National Cancer Institute, with additional support from Amgen. The research was conducted by the Southwest Oncology Group, a cooperative organization of researchers that conducts clinical trials supported by the cancer institute.
Other authors of the study are J. Kash, Edward Hospital in Naperville, Il.; W.E. Barlow, Cancer Research and Biostatistics in Seattle; J. R. Garlow, Seattle Cancer Care Alliance; D. Lew, Southwest Oncology Group Statistical Center in Seattle; L. E. Flaherty, Wayne State University in Detroit; M.E. Royce, University of New Mexico; G. N. Hortobagyi, M.D. Anderson Cancer Center in Houston and R. B. Livingston, Arizona Cancer Center in Tucson.