M-protein kinetics in multiple myeloma treated with melphalan, ifosfamide, prednisolone, nitrosourea and vincristine in combination.

Patients with multiple myeloma were treated chemotherapeutically with a combination of melphalan, ifosfamide, prednisolone, nitrosourea and vincristine (MIP-NV therapy). The M-protein kinetics during the course of MIP-NV therapy was studied. The kinetics of serum and urinary M-protein in the first cycle of the chemotherapy was classified into four patterns, and the mode of change in the M-protein level over the entire course of chemotherapy was classified into four prototypes. There were intimate relationships among M-protein kinetics patterns in the first cycle of the chemotherapy, the effect of the chemotherapy on M-protein reduction, maturity of myeloma cells, pretreatment labeling index and clinical stage of the disease. Moreover, analyzing the prototypes, it was found that both the time for maximum M-protein reduction and the rate of increase in the M-protein level after maximum M-protein reduction affected the survival time. To predict the effect of the chemotherapy on M-protein reduction and survival time, it was useful to analyze subgroups, which were classified according to the M-protein kinetics pattern in the first cycle, the time for maximum M-protein reduction and the rate of increase in the M-protein level after maximum M-protein reduction.