Effect of peg-filgrastim-supported dose-dense adjuvant chemotherapy on the peripheral blood leukocyte phenotype in breast cancer patients

Abstract

Abstract. The aim of this study was to evaluate the effect of dose-dense adjuvant chemotherapy regimens with pegfilgrastim support on the phenotype of peripheral blood leukocytes in breast cancer patients. We evaluated the leukocyte phenotype of 14 patients aged 46-67 years undergoing 4 courses of chemotherapy with either epirubucin/ cyclophosphamide (n=7) or 5-fluorouracil/epirubucin/ cyclophosphamide (n=7) followed by 4 courses of taxol supported by peg-filgrastim (6 mg) administered 72 h after each chemotherapy course. The overall leukocyte number significantly increased from the first treatment course, while total lymphocytes tended to decrease with a negative peak following the 6th course (p=0.03). B (CD19 + , CD20 + ) and early B lymphocyte subsets (CD20 + /CD38 + ) significantly decreased during treatment (p<0.05), while T lymphocyte subsets did not show significant changes, except a decrease in T helper (CD4 + ) cells. Immature T lymphocytes (CD4 + / CD8 + subset), dendritic cells (CD11c + ) and NK cells (CD56 + ) increased with respect to the baseline. Our results suggest that dose-dense chemotherapy programs with the support of pegfilgrastim did not significantly impair the immune system of breast cancer patients and allowed for a rapid restoration of most immune competent cells. These observations may have important clinical implications with a view to vaccination or other immunotherapeutic approaches to solid tumours.