Predictive value of post-transplant bone marrow plasma cell percent in multiple myeloma patients undergone autologous transplantation.

Autologous stem cell transplantation (ASCT) has become the treatment of choice for patients with multiple myeloma (MM). Studies have shown that maintenance treatment with interferon-alpha is associated with improved survival rates following ASCT. However, despite these recent advances in regimes, relapses are inevitable; thus, the prediction of relapse following ASCT requires assessment.We retrospectively analyzed 39 patients who received ASCT between 2003 and 2008. All patients received chemotherapy with vincristine, adriamycin, and dexamethasone (VAD), and ASCT was performed following high-dose melphalan conditioning therapy. We evaluated the influence of the post-transplant day +14 (D+14) bone marrow plasma cell percent (BMPCp) (≥ 2 vs. < 2%), international scoring system (ISS) stage (II vs. III), response after 3 cycles of VAD therapy (complete response [CR] vs. non-CR), deletion of chromosome 13q (del[13q]) (presence of the abnormality vs. absence), and BMPCp at diagnosis (≥ 50 vs. < 50%) on progression-free survival (PFS) and overall survival (OS).During the median follow-up of 28.0 months, the median PFS and OS were 29.1 and 42.1 months, respectively. By univariate analysis, ISS stage III at diagnosis, BMPCp ≥ 50% at diagnosis, CR after 3 cycles of VAD therapy, del (13q) by fluorescence in situ hybridization, and BMPCp ≥ 2% at post-transplant D+14 were correlated with PFS and OS. A multivariate analysis revealed that a post-transplant D+14 BMPCp ≥ 2% (PFS, hazard ratio [HR] = 4.426, p = 0.008; OS, HR = 3.545, p = 0.038) and CR after 3 cycles of VAD therapy (PFS, HR = 0.072, p = 0.014; OS, HR = 0.055, p = 0.015) were independent prognostic parameters.Post-transplant D+14 BMPCp is a useful parameter for predicting the outcome for patients with MM receiving ASCT.