[Effect of bortezomib-based induction therapy on the peripheral blood stem cell harvest in multiple myeloma].

A high dose of melphalan followed by autologous stem cell transplantation (ASCT) is considered as the standard therapy for multiple myeloma. For induction therapy, 78 patients received conventional regimens (control group) and 32 patients received bortezomib-containing regimens (bortezomib group). We retrospectively compared the yield of harvested CD34+ cells between the two groups. In order to mobilize CD34+ cells, 83% of the control group and 63% of the bortezomib group received a high dose of cyclophosphamide followed by G-CSF, and 12% of the control group received a high dose of etoposide instead of cyclophosphamide. Furthermore, 5% of the control group and 38% of the bortezomib group received G-CSF alone for CD34+ cell mobilization. Overall, the yield of CD34+ cells was higher in the control group than in the bortezomib group (7.4 vs. 5.2×10(6)/kg, P=0.004). Regarding the patients mobilized by a high dose of cyclophosphamide followed by G-CSF, the rate of achieving CD34+ cells >2.0×10(6) cells/kg was similar. Bortezomib did not significantly affect the successful collection of at least CD34+ cells > 2.0×10(6) cells/kg after mobilization with a high dose of cyclophosphamide followed by G-CSF.