Chemotherapy Dose Does Not Differ Between Black Women and White Women with Breast Cancer

May 14, 2005A new study from the National Surgical Adjuvant Breast and Bowel Project (NSABP) shows that higher rates of breast cancer deaths for black women are not due to lower doses of chemotherapy. Black women are more likely to die from breast cancer than white women, but the reasons are unknown.Previous research shows that black people tend to have lower numbers of white blood cells (WBCs) than white people. Some chemotherapy drugs further reduce the number of WBCs, which increases the chance of developing a serious infection while receiving chemotherapy. The researchers thought that doctors may be giving black women lower doses of chemotherapy to avoid dangerous drops in white blood cell counts, and this difference might explain why black women are more likely to die from breast cancer than white women.In this study, doctors compared the WBC count and dose of the chemotherapy drugs doxorubicin (Adriamycin) and cyclophosphamide (Cytoxan, Neosar) given to 1,041 black women and 9,639 white women. Although the initial WBC counts were slightly lower in blacks compared with whites, the total dose of chemotherapy was similar."Our study shows that chemotherapy dosing is equal for white and black women, and that chemotherapy dose is not the likely cause of the difference in survival between black and white women with breast cancer," said Charles R. Thomas, Jr., MD, Professor and Vice Chairman, Department of Radiation Oncology and Professor of Medical Oncology, University of Texas Health Science Center, speaking on behalf of the NSABP.What this means for patientsAlthough black women may have fewer WBCs before starting chemotherapy treatment, this condition does not have to affect overall chemotherapy dose. Differences in breast cancer mortality cannot be attributed to chemotherapy dose, and more research is needed to learn why more black women die from breast cancer.