Mobilization of peripheral blood progenitor cells in patients with breast cancer: a prospective randomized trial comparing rhG-CSF with the combination of rhG-CSF plus rhEpo after VIP-E chemotherapy.

Peripheral blood progenitor cells (PBPC) can be mobilized by chemotherapy, cytokines, or the combination of both. Recently, data from two non-randomized studies were published, showing an advantage for a combination of rhG-CSF plus rhEpo compared to rhG-CSF alone in mobilization of PBPC. To address this question we initiated a prospective, randomized trial in patients with breast cancer. Thirty (28 female, two male) of 32 randomized patients were evaluable. After primary surgery, therapy consisted of two cycles of VIP-E chemotherapy followed by high-dose (HD) chemotherapy with VIC. Mobilization and harvest of PBPC followed cycle 2. Group A received 5 microg rhG-CSF/kg body weight (bw) plus 150 IU rhEpo/kg bw. Group B was treated with 5 microg rhG-CSF/kg bw from dl until end of harvest. In the peripheral blood CD34+ cells as well as colony-forming units (CFU) started to rise on d8 with a peak on d10, followed by a decrease. No significant differences were observed between the groups. Furthermore, there was no significant difference with regard to MNC, CD34+ cells BFU-E and CFU-GM in apheresis products. Transplantation of > 1 x 10(6) CD34+ cells/kg bw after HD chemotherapy resulted in normal hematological recovery of all patients. No differences were observed in time to neutrophil or platelet recovery and need for blood product support. In this study addition of rhEpo to our standard mobilization chemotherapy did not result in improved mobilization of PBPC or in clinical benefits after HD chemotherapy.