Researchers in the Ohio State University Comprehensive Cancer Center Arthur G. James Cancer Hospital and Richard J. Solove Research Institute studied 227 women enrolled in a multi-year study examining the relationship between stress and immunity in women with breast cancer. They divided the group into women who received taxanes as part of their treatment (55) and those who did not (172).
Researchers took blood from the patients and measured levels of key markers of the patients' immune status at two points in time, immediately after the women joined the study and one year following completion of treatment. Their analysis of the blood looked at the activity of the patient's T cells (white blood cells that can fight infections and cancer cells) and natural killer (NK) cells (another type of white blood cell that can kill cancer cells and cells infected with viruses).
They found that T cell growth was 37 percent higher and that the cancer killing activity of the NK cells was 39 percent higher in women receiving taxanes versus those who did not.
Scientists controlled for multiple variables that might contribute to the strength of the patients' immune function, including age, menopausal status, hormone receptor status, treatment, hormonal therapy at 12 months and cell counts, among others.
"This was totally unexpected," says Dr. William Carson, a surgeon and associate director of clinical research for the OSUCCC-James. "Most oncologists believe taxanes just like the rest of the chemotherapeutic agents we use suppress the immune system, not enhance it."
The study is published in the May 15 issue of Clinical Cancer Research.