Stem cell transplantation for patients with myelodysplastic syndrome and secondary leukemias

Most patients with myelodysplastic syndrome (MDS) are too old to be conside red for intensive treatment, such as stem cell transplantation (SCT). Allog eneic SCT from an HLA-identical sibling donor is the curative treatment opt ion for a relatively young patient (younger than 60 years) with MDS or seco ndary acute myeloid leukemia. Older age and lack of sibling donors limit th is application. Alternative stem cell sources, such as unrelated donors, no nidentical family members, or autologous transplants, have been used more r ecently. Most patients may benefit optimally from an allogeneic SCT when th e transplant is performed as soon as an HLA-identical family member has bee n identified. Progression to more advanced leukemia conditions will be asso ciated with a higher failure rate due to increased relapse rate after SCT a nd higher treatment-related mortality. Delay of the transplant may be justi fied in a minority of patients with refractory anemia or refractory anemia with ringed sideroblasts without profound cytopenias or complex cytogenetic abnormalities and no need for erythrocyte transfusions. The present data f rom patients transplanted with sources of hematopoietic stem cells other th an histocompatible sibling donors give an indication of the potential of ot her forms of transplantation. The disease-free survival of patients transpl anted with histocompatible sibling donors was significantly better than the outcome of patients transplanted with other sources of stem cells. About o ne-third of the patients transplanted with stem cells from histocompatible siblings and about one-quarter of the patients with stem cells from other s ources may be free of disease for 3 years or longer. The results of these t reatment forms have improved considerably, but the continuing high treatmen t-related mortality warrants that these patients should be treated within i nvestigational protocols. Int J Hematol. 2000;72:151-156. (C) 2000 The Japa nese Society of Hematology.