Hematopoietic stem cell transplantation (HSCT) remains the only curative treatment in patients with higher risk myelodysplastic syndrome (MDS), but the choice of the optimal alternative stem cell source is still a subject of debate in patients lacking an HLA-matched sibling donor. Here, we report on a large series of patients with MDS (N = 631) transplanted either with mobilized peripheral stem cells (PBs) from unrelated donors (n = 502) or with umbilical cord blood transplant (UCB, n = 129) as alternative grafts after reduced-intensity conditioning. Neutrophil engraftment was higher after PB (98% versus 78%, P < .0001). Acute graft-versus-host disease (GVHD) was similar after PB (31%) and UCB (29%), and chronic GVHD incidence was higher after PB (41% versus 23%). Two-year nonrelapse mortality was lower after PB (31% versus 42% P = .03). There was a better overall survival (OS) and disease-free survival (DFS) after PB (49% ± 2% versus 30% ± 4%, P < .0001 and 44% ± 2% versus 28% ± 4%, P < .0001). Multivariate analysis confirmed the advantage of PB for treatment-related mortality, OS, and DFS, whereas relative risk of chronic GVHD was similar. A multivariate analysis comparing PB from a 10/10 HLA-matched donor, PB from a 9/10 HLA-matched donor, and UCB showed an advantage on treatment-related mortality, DFS, and OS only in 10/10 PB. We conclude that in MDS patients lacking an HLA-matched sibling donor, PB from a 10/10 HLA-matched unrelated donor is the preferred source of hematopoietic stem cells. HLA-mismatched unrelated donor or cord blood seem to give similar inferior results except for neutrophil engraftment, which is delayed after UCB.
Keywords: Alternative donors; Cord blood transplant; Myelodysplastic syndrome; Reduced-intensity conditioning regimen.
Copyright © 2015 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.