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.