MOBILIZATION, COLLECTION, AND CHARACTERIZATION OF PERIPHERAL-BLOOD HEMATOPOIETIC PROGENITORS AFTER CHEMOTHERAPY WITH EPIRUBICIN, PACLITAXEL, AND GRANULOCYTE-COLONY-STIMULATING FACTOR ADMINISTERED TO PATIENTS WITH METASTATIC BREAST-CARCINOMA

BACKGROUND, As single agents, both paclitaxel and epirubicin in combin ation with cytokines can mobilize peripheral blood progenitor cells (P BPCs). The authors have demonstrated previously that the combination o f epirubicin and paclitaxel is very active against metastatic breast c arcinoma and tolerated by patients. METHODS, Twenty-one patients with metastatic breast carcinoma received epirubicin 90 mg/m(2) in combinat ion with paclitaxel 200 mg/m(2) given as a 3-hour infusion, and granul ocyte-colony stimulating factor (G-CSF) starting 24 hours after chemot herapy to mobilize PBPCs. An immunophenotypic analysis for CD3, CD4, C D8, CD19, CD33, CD34, and CD38 antigen expression was performed on aph eresis products. Eighteen patients underwent high dose chemotherapy an d were engrafted with PBPCs primed with paclitaxel, epirubicin, and G- CSF. RESULTS, The median number of circulating CD34+ cells at peak was 70/mu L; in the patients less heavily pretreated, it was 106.7/mu L. The mean number of CD34+, CD34+/CD33-, and CD34+/CD38- cells/kg collec ted per apheresis was 6.3 x 10(6), 2.0 x 10(6), and 0.18 x 10(6), resp ectively. The mean number of CD34+ cells/kg per apheresis was 7.8 x 10 (6) when the preleukapheresis CD34+ cell count was more than 50/mu L a nd 0.9 x 10(6) when the CD34+ cell count was less than 50/mu L. The me an number of CD3+, CD4+, and CD8+ cells/kg collected per apheresis was 90 x 10(6), 50 x 10(6), and 30 x 10(6), respectively. CONCLUSIONS, Ep irubicin plus paclitaxel in combination with G-CSF mobilizes PBPCs, in cluding more primitive progenitors capable of supporting myeloablative treatment. Moreover, the mononuclear cells collected in this study co ntained high levels of cytotoxic effector cells suitable for ex vivo m anipulation to augment the antitumor effect. (C) 1998 American Cancer Society.