Kinetics of PBPC mobilization by cyclophosphamide, as compared with that by epirubicin/paclitaxel followed by G-CSF support: implications for optimal timing of PBPC harvest.
BACKGROUND
Limited information is available on the mobilization kinetics of autologous PBPCs after induction with various chemotherapy regimens. With PBPC mobilization in patients with breast cancer used as a model for chemotherapy-induced PBPC recruitment, the kinetics of progenitor cells mobilized either with cyclophosphamide (CY) or epirubicin/paclitaxel (EPI-TAX) followed by the administration of G-CSF was compared.


METHODS
The study included a total of 86 patients with breast cancer (stage II-IV) receiving either CY (n = 39) or EPI-TAX (n = 47), both followed by G-CSF support. The progenitor cell content in peripheral blood and apheresis components was monitored by flow cytometric enumeration of CD34+ cells. PBPC collection was started when the threshold of >20 x 10(6) CD34+ cells per L of peripheral blood was reached.


RESULTS
The PBPC collection was begun a median of 9 days after the administration of EPI-TAX followed by G-CSF support, as compared to a median of 13 days after mobilization with CY plus G-CSF. After treatment with CY, the total numbers of PBPCs peaked on Day 1 of apheresis, and they rapidly declined thereafter. In contrast, treatment with EPI-TAX followed by G-CSF administration led to a steady mobilization of CD34+ cells during leukapheresis. The difference in the mobilization patterns with CY and EPI-TAX resulted in a greater yield of CD34+ cells per L of processed blood volume. Compared to EPI-TAX, mobilization with CY required the overall processing of 30 percent less whole-blood volume to reach the target yield of > or = 10 x 10(6) CD34+ cells per kg of body weight. After a median of three apheresis procedures, however, both CY+G-CSF and EPI-TAX+G-CSF were equally effective in obtaining this target yield.


CONCLUSIONS
These results imply that specific PBPC mobilization as part of a given chemotherapy regimen should be taken into consideration before the planning of a PBPC harvest.
Dettke
M
M
Departments of Blood Group Serology and Transfusion Medicine and of Internal Medicine I, Bone Marrow Transplantation Unit, University Hospital of Vienna, Austria. markus.dettke@univie.ac.at
Greinix
H T
HT
Kalhs
P
P
Kührer
I
I
Worel
N
N
Höcker
P
P
D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000494:pharmacology*; D001810:Blood Volume; D001943:Breast Neoplasms / Q000097:blood / Q000628:therapy*; D003520:Cyclophosphamide / Q000494:pharmacology*; D015251:Epirubicin / Q000008:administration & dosage; D005260:Female; D016179:Granulocyte Colony-Stimulating Factor / Q000494:pharmacology*; D019650:Hematopoietic Stem Cell Mobilization; D006801:Humans; D007937:Leukapheresis; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D017239:Paclitaxel / Q000008:administration & dosage; D013997:Time Factors
D016179:Granulocyte Colony-Stimulating Factor; D015251:Epirubicin; D003520:Cyclophosphamide; D017239:Paclitaxel