Collection of peripheral blood stem cells with granulocyte-colony-stimulating factor alone in testicular cancer patients.

BACKGROUND: High-dose chemotherapy with the transplantation of peripheral blood stem cells (PBSC) has been performed for the treatment of advanced testicular cancer patients. Recently, it has been reported that, in healthy donors, a large quantity of stem cells can be transferred to peripheral blood using granulocyte-colony-stimulating factor (G-CSF) alone. Therefore, it was decided to try to harvest PBSC from three patients having testicular cancers with G-CSF alone. METHODS: The three patients with testicular cancer were 26, 56 and 62-years-old. They had undergone five, two and three cycles of chemotherapy, respectively, but no radiation therapy. Granulocyte colony-stimulating factor was subcutaneously injected (250 microg) into each patient twice per day for 6 days. Peripheral blood stem cells were harvested for 3 days (days 4-6) and mononuclear cells (MNC), CD34-positive cells and colony-forming units of granulocyte-macrophage (CFU-GM) in PBSC collected by apheresis were measured. RESULTS: Apheresis showed that the total MNC count was 20.2 x 10(8)/kg (range, 10.6-25.9 x 10(8)/kg), the CD34-positive cell count was 0.98 x 10(6)/kg (range, 0.75-1.4 x 10(6)/kg) and the total CFU-GM count was 1.36 x 10(5)/kg (range, 0.25-3.0 x 10(5)/kg). CONCLUSION: After mobilization of peripheral blood stem cells with G-CSF alone, sufficient amounts of MNC were obtained from testicular cancer patients who had undergone chemotherapy several times. However, sufficient amounts of CD34-positive cells and CFU-GM could not be obtained. These results suggested that the G-CSF dose was not adequate for harvesting sufficient amounts of CD34-positive cells and CFU-GM.