Autologous stem cell transplantation after first remission induction treatment in multiple myeloma: a report of the French Registry on autologous transplantation in multiple myeloma.

Eighteen French centers reported 133 autologous stem cell transplantations performed after first remission induction in multiple myeloma. The source of stem cell was marrow (81 cases), blood (51 cases) or marrow plus blood (1 case). The immediate outcome after transplantation was 49 (37%) complete remissions (CRs) (13 maintained, 36 achieved), 61 (46%) partial remissions, 17 failures and 5 toxic deaths. With a median follow-up of 35 months, the median remission duration was 33 months, the median time to treatment failure was 22 months. The median survival was 46 months overall, 54 months for the 103 patients responding to primary treatment, and 30 months for the 30 nonresponders. In univariate analysis, the outcome was influenced by age, Ig isotype, initial beta 2 microglobulin level, response to initial chemotherapy, plasma cell marrow involvement at the time of harvest, albumin and beta 2 microglobulin level at the time of transplantation, and CR achievement after transplantation. In multivariate analysis, the most important prognostic factor was the quality of response after transplantation. The conditioning regimen and the source of stem cell had no significant impact on immediate and long-term results. Maintenance therapy with interferon alpha did not appear to prolong remission duration or survival. Autologous stem cell transplantation is an effective consolidation for patients responding to primary treatment and a salvage therapy for some nonresponding patients. This approach has to be compared to conventional chemotherapy in prospective randomized studies. The critical impact of CR achievement on survival implies new strategies to increase the CR rate.