Stable hematopoietic recovery after peripheral blood stem cell transplantation in patients receiving high-dose chemotherapy for advanced germ cell tumors.

Aim: The objective of this study was to evaluate the utility of CD34-positive peripheral blood stem cell transplantation (PBSCT) in the hematopoietic recovery, in patients receiving high-dose chemotherapy (HDCT), for advanced germ cell tumor (GCT).

Materials And Methods: This study included 41 patients with advanced GCT, who were treated with HTCT combined with PBSCT. PBSCs were harvested after conditioning chemotherapy followed by the administration of granulocyte colony-stimulating factor. A retrospective analysis of a total of 86 PBSCTs was carried out focusing on the effects of several factors, including age (<35 years versus > or = 35 years), CD34-positive cell dose (<5.0 x10(6)/kg versus > or =5.0 x10(6)/kg), indication of HDCT (first-line versus salvage) and previous history of HDCT before PBSCT (with versus without), on hematopoietic recovery after PBSCT.

Results: The median number of CD34-positive PBSCs collected during a single apheresis and the median cumulative number of CD34-positive PBSCs from each patient were 8.3x10(6)/kg and 23.2x10(6)/kg, respectively. The median number of PBSCT performed in each patient was two and the median number of CD34-positive cells transplanted during a single course was 5.7x10(6)/kg. The median recovery times to white blood cells (WBC) greater than 500/microl, 1000/microl and 2000/microl were 8, 9 and 10 days, respectively, following PBSCT, while that to neutrophils greater than 500/microl and that to platelets greater than 50000/microl were 9 and 13 days, respectively, following PBSCT Only the recovery time to platelet count greater than 50000/microl was significantly affected by age; however, there were no significant differences in the recovery of WBC, neutrophils and platelets in relation to several parameters examined.

Conclusion: These findings suggest that CD34-positive PBSCT may facilitate stable hematopoietic recovery after HDCT in patients with advanced GCT, and that HDCT, if combined with PBSCT, could be performed with comparative safety in such patients, irrespective of their individual characteristics.