Plasmablastic morphology is an independent predictor of poor survival after autologous stem-cell transplantation for multiple myeloma

Purpose: To study the prognostic value of plasmablastic morphology after au tologous stem-cell transplantation for relapsed or primary refractory myelo ma. Patients and Methods: Seventy-five patients were studied, Investigators bli nded to the clinical derails of the individual cases reviewed bone marrow a spirate slides to determine plasmablastic classification. Plasma-blasts wer e defined using strict, well-described criteria. Plasmablastic morphology w as considered to be present (plasmablastic myeloma) when 2% or more plasma- blasts were present in the plasma-cell population. Results: Patients underwent transplantation 5 to 88 months (median, 20 mont hs) after the initial diagnosis of myeloma. Twenty-eight percent of patient s had plasmablastic morphology. A significantly greater proportion of patie nts with plasmablastic morphology had abnormal cytogenetics compared with t hose with non-plasmablastic classification (73% v31%, respectively; P =.003 ). The overall survival rate measured from the time of transplantation was significantly worse in patients with plasmablastic morphology compared with those without (median survival time, 5 months v 24 months, respectively; P <.001). Progression-free survival time was shortened also, with ct median time of 4 months compared with 12 months, respectively (P <.001). In the mu ltivariate analysis, plasmablastic classification was the most powerful pro gnostic factor after transplantation for both overall (P =.001)and progress ion-free survival rates (P <.001). We also identified three risk groups bas ed on plasmablastic morphology: plasma-cell labeling index, lactate dehydro genase, and cytogenetics. The median overall survival time was 38 months wh en none of these factors was abnormal, 17 months with one abnormal factor, and 8 months with two or more abnormal factors (P <.001), Conclusion: Plasmablastic morphology is a powerful independent predictor of poor survival rate after autologous stem-cell transplantation for relapsed or primary refractory myeloma. J Clin Oncol 17:1551-1557, (C) 1999 by Amer ican Society of Clinical Oncology.