Recently, several new therapies have become available to treat patients with myelodysplastic syndromes (MDS). Azanucleosides such as azacitidine (Vidaza, Celgene) and decitabine (Dacogen, Eisai), which exhibit dual properties as pyrimidine analogs and hypomethylating agents, change the natural history of MDS, reduce transfusion requirements, extend survival, and delay progression to acute leukemia. 1-5 Despite improvements in clinical outcomes with azanucleoside treatment, nearly all MDS patients suffer from disease relapse and progression. Thus, the only potentially curative option for most patients with MDS is allogeneic hematopoietic cell transplantation (HCT). 6-10

It is challenging to determine when to proceed to HCT in patients with MDS. In general, younger patients with lower burdens of MDS, fewer comorbidities, and less transfusion dependence tend to achieve better post-transplant outcomes. 11-15 Early studies of pretransplant induction chemotherapy with cytotoxic agents in MDS patients found no clear post-transplant benefits. 13, 16-21 In 2004, a decision model developed by Cutler and colleagues indicated a survival advantage with early HCT among patients classified as intermediate-2 and high-risk MDS based on International Prognostic Scoring System (IPSS) criteria. 22