New Treatment for Aggressive Breast Cancer Shows Some Promise
Early studies found small improvement with combo therapy for HER2-positive disease
The drawbacks of this combination therapy are cost and side effects, Piccart-Gebhart said. Targeted therapies cost tens of thousands of dollars, and combining the two drugs increases toxic side effects such as diarrhea and rash.
"There is a price to pay in terms of side effects," she said. "There will be a price to pay in terms of drug costs."
This study was supported by funds from GlaxoSmithKline. Piccart-Gebhart has received honoraria from Roche, and her institution has received research funding from GlaxoSmithKline.
The second study involved 156 patients who received chemotherapy and Herceptin before surgery. However, this study focused on the levels of immune cells called lymphocytes that had infiltrated the breast tumors.
For every 10 percent increase in the levels of tumor-infiltrating lymphocytes, there was a 16 percent increase in the number of patients whose breast tumors were eradicated, said lead researcher Dr. Sherene Loi.
Loi is a medical oncologist and head of the translational breast cancer genomics lab at the Peter MacCallum Cancer Center in Melbourne, Australia.
She said Herceptin might serve to activate the immune cells. However, her team found that not all women have high levels of these immune cells in their tumors.
"Previously, breast cancer has not thought to be suitable for immunotherapy approaches," Loi said. "Our results provide evidence that this could be a new strategy for treatment in breast cancer."
The third study compared the effectiveness of a combination chemotherapy using the drugs docetaxel and carboplatin against traditional chemotherapy with medications called anthracyclines.
Anthracyclines are effective in treating HER2-positive breast cancer, but have very toxic side effects that can lead to congestive heart failure and leukemia.
Doctors found that 92 percent of 3,231 women treated with the new combination chemo survived more than three years with no recurrence of their cancer.
These results make the new combination a viable alternative to anthracycline-based chemotherapy, said lead researcher Dr. Dennis Slamon, director of clinical/translational research at the Jonsson Comprehensive Cancer Center at the University of California, Los Angeles.
"It is going to be difficult to develop treatment regimens that have even better response rates than that," said Slamon, who is also chief of hematology/oncology with UCLA's department of medicine