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 sho rtened in patients who receive peripheral blood progenitor cells (PBPC ). To estimate the clinical value of granulocyte colony-stimulating fa ctor, we examined a cohort of 26 consecutive patients with advanced br east cancer who received one or two cycles of high-dose chemotherapy w ith PBPC rescue with or without filgrastim. Thirty-five courses of hig h-dose ICE (ifosfamide, carboplatin, etoposide) chemotherapy were admi nistered and evaluated. All patients received PBPC rescue. Sixteen pat ients (21 courses) received subcutaneous filgrastim (5 mg/kg) followin g 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 rece ived filgrastim versus 10 days among patients who received standard su pport care only (P<0.01). The administration of filgrastim was not ass ociated with a reduction in the duration of hospitalization, in the to tal 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 do se administered in the study. Therefore, any effect of filgrastim was probably masked by the use of a large number of PBPC. Larger prospecti ve randomized studies, specifically focused on the utility of the admi nistration of growth factors following high-dose chemotherapy and PBPC rescue, may be warranted to know whether the administration of filgra stim after PBPC transplantation is really necessary.