Allogeneic haematopoietic cell transplantation for patients with myelodysplastic syndrome (MDS)

Allogeneic hematopoietic cell transplantation (HCT) is a curative treatment option for patients with myelodysplastic syndromes (MDS). Although improvements in donor selection, supportive therapy and post-grafting immunosuppression have been achieved throughout the last two decades, allogeneic HCT after standard conditioning remains restricted to a small minority of patients. The long-term success of allogeneic HCT depends on several disease and patient specific risk factors, leading to probabilities of disease-free survival after three years between 20% and 65%. Early transplantation seems to be warranted especially in patients with intermediate-2 and high-risk IPSS scores as defined by marrow blasts and cytogenetics. The outcome of grafts from matched unrelated donors is comparable to that from matched sibling donors. Many investigators favour the use of peripheral blood stem cells instead of marrow grafts. Given that most patients with MDS are older than 60 years, the development of less toxic conditioning regimens has allowed patients with a higher comorbidity score to be transplanted with similar results as with standard conditioning in younger cohorts. Still, a reduced-intensity of the preparative regimen increases the risk of relapse. Therefore current clinical trials focus on the relevance of pretransplant induction therapy and the direct comparison of standard-intensity with reduced-intensity conditioning. Additional efforts will be made to integrate new pharmacological strategies in order to reduce the risk of relapse. Further improvements are needed before allogeneic HCT will become the standard therapy for high-risk MDS.