Current status of pretransplant intensive chemotherapy or hypomethylating agents for myelodysplastic syndrome

Myelodysplastic syndrome is a heterogeneous disease with survival probabilities ranging from a few months to several years. Allogeneic hematopoietic cell transplantation (HCT) remains the only curative treatment. Although access (up to 75 years) and outcome of HCT have improved steadily in recent years, high relapse rates and, to a lower extent, treatment related mortalities are a persisting problem. Reduction of tumor burden before HCT has been shown to decrease relapse incidence and often overall survival (OS) in hematological malignancies but the role of pretransplant therapy in MDS remains controversial. We reviewed the role of pretransplant therapy on outcome in MDS patients. No prospective randomized trial addressed this issue so far. Retrospective studies have shown that pretransplant therapy reduces the risk of relapse, but does not improve survival. In addition, registry studies from diagnosis with standard protocols are proposed in order to exclude patient selection. With the availability of new, more effective and low-toxicity therapies, it may be possible to achieve a significant improvement of OS in the future.