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 b lood stem cells (PBSC) has been performed for the treatment of advanced tes ticular cancer patients. Recently, it has been reported that, in healthy do nors, a large quantity of stem cells can be transferred to peripheral blood using granulocyte-colony-stimulating factor (G-CSF) alone. Therefore, it w as decided to try to harvest PBSC from three patients having testicular can cers 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, respec tively, but no radiation therapy. Granulocyte colony-stimulating factor was subcutaneously injected (250 mu g) into each patient twice per day for 6 d ays. Peripheral blood stem cells were harvested for 3 days (days 4-6) and m ononuclear cells (MNC), CD34-positive cells and colony-forming units of gra nulocyte-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 (ran ge, 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)/k g (range, 0.25-3.0 x 10(5)/kg). Conclusion: After mobilization of peripheral blood stem cells with G-CSF al one, sufficient amounts of MNC were obtained from testicular cancer patient s who had undergone chemotherapy several times. However, sufficient amounts of CD34-positive cells and CFU-GM could not be obtained. These results sug gested that the G-CSF dose was not adequate for harvesting sufficient amoun ts of CD34-positive cells and CFU-GM.