Hematopoietic cell transplantation for adult patients with myelodysplastic syndromes and myeloproliferative disorders.

Hematopoietic cell transplantation (HCT) is currently the only treatment with curative potential for myelodysplastic syndromes (MDS) and myeloproliferative disorders (MPD). Among patients with less advanced MDS, 3-year survival rates of 65% to 75% are achieved with HLA-identical related and unrelated donors. The probability of relapse is less than 5%. Among patients with advanced MDS (> or = 5% marrow blasts), about 35% to 45% who receive transplants from related donors and 25% to 30% who receive transplants from unrelated donors are in remission beyond 3 years. The incidence of posttransplantation relapse is 10% to 35%. Criteria of the International Prognostic Scoring System (originally developed for nontransplant patients) also predict relapse and survival after HCT. Transplantation is successful in 50% to 80% of patients with MPD if performed before leukemic transformation. Depending on the individual risk profile, a considerable number of patients with MDS or MPD are cured by allogeneic HCT. However, HCT should be performed before disease progression. Outcome of patients with treatment-related MDS or with relapse after transplantation remains poor. At present, no definite conclusions can be made with regard to reduced-intensity transplantation regimens.