The use of granulocyte colony-stimulating factors following peripheral blood progenitor cell rescue after high-dose chemotherapy for advanced breast cancer: A prospective study

The use of high-dose chemotherapy followed by hematopoietic rescue is increasing worldwide for solid tumors. Several studies have suggested that the period of absolute neutrophil count (ANC, <500/ml) may be shortened in patients who receive peripheral blood progenitor cells (PBPC). To estimate the clinical value of granulocyte colony-stimulating factor, we examined a cohort of 26 consecutive patients with advanced breast cancer who received one or two cycles of high-dose chemotherapy with PBPC rescue with or without filgrastim. Thirty-five courses of high-dose ICE (ifosfamide, carboplatin, etoposide) chemotherapy were administered and evaluated. All patients received PBPC rescue. Sixteen patients (21 courses) received subcutaneous filgrastim (5 mg/kg) following PBPC infusion. Recovery to greater than or equal to 500 ANC occurred at a median time of 7 days post PBPC infusion among patients who received filgrastim versus 10 days among patients who received standard support care only (P<0.01). The administration of filgrastim was not associated with a reduction in the duration of hospitalization, in the total number of days on nonprophylactic antibiotics, number of red blood cell transfusions, time to platelet engraftment, or number of febrile days. This could be the consequence of the high hematopoietic cell dose administered in the study. Therefore, any effect of filgrastim was probably masked by the use of a large number of PBPC. Larger prospective randomized studies, specifically focused on the utility of the administration of growth factors following high-dose chemotherapy and PBPC rescue, may be warranted to know whether the administration of filgrastim after PBPC transplantation is really necessary.