Progress in hematopoietic stem cell transplantation in multiple myeloma.

Purpose Of Review: An attempt is made to value the place of autologous and allogeneic hematopoietic stem cell transplantation in the treatment of multiple myeloma. Recent progress with each treatment modality has significantly changed the outcome for myeloma patients.

Recent Findings: The gold standard for conditioning treatment before autologous transplantation is melphalan 200 mg/m, and the use of peripheral blood stem cells is superior to that of bone marrow. Tandem autologous transplantation is superior to single autologous transplantation, at least for patients who do not respond with complete remission to the first transplant. Allogeneic transplantation using standard high-dose myeloablative conditioning reduces the relapse rate in comparison with autologous transplantation; however, treatment-related mortality is significantly higher. Progress in allogeneic transplantation has been significant, and transplant-related mortality has been reduced. The recent use of nonmyeloablative reduced-intensity conditioning has significantly decreased transplant-related mortality; however, the relapse rate is higher than with standard conditioning, and therefore no significant improvement in overall survival has as yet been seen. Relapse following allogeneic transplantation can be counteracted by donor lymphocyte infusions, but the survival results are so far inconclusive.

Summary: Autologous transplantation is still the first choice for most myeloma patients, but it does not seem to be curative. Therefore, allogeneic transplantation should be continued in clinical trials exploring new conditioning methods, the graft-versus-myeloma effect of new cell types, and its combination with new targeted drugs such as bortezomib and lenalidomide.