Clinical application of growth factors for collection of circulating hematopoietic progenitors in breast cancer patients treated with high-dose cyclophosphamide

Seventy-seven (68 operable breast cancer with > 9 metastatic axillary nodes and 9 inflammatory breast cancer) entered this study. During hematopoietic recovery after cancer therapy with high-dose cyclophosphamide (7 g/m2; HD-CTX) circulating hematopoietic progenitors were collected by leukapheresis (LK) in all patients and then cryopreserved for autologous transplantation. Following HD-CTX, 70 patients were treated with hematopoietic growth factor(s) for 14 days: 38 with rhGM-CSF (group a), 16 with rhIL-3 (group b), 11 with sequential rhIL-3 and rhGM-CSF (group c), 5 with sequential rhIL-3 and rhG-CSF (group d). Seven control patients (group e) did not receive any growth factor. Leukaphereses, carried out over 2-4 consecutive days per patient, were started earlier in group c and in group d patients (mean day: +12 after HD-CTX). The sequential administration of rhIL-3 and rhG-CSF (group d) resulted in clearly higher yield of CFU-GM and CD34+ cells per leukapheresis (65.9 x 10(4)/Kg versus 20.9 x 10(6)/Kg, respectively) if compared with other groups of treatment.