Comparison of long-term outcome for AML patients alive free of disease 2 years after allogeneic hematopoietic cell transplantation with umbilical cord blood versus unrelated donor: a study from the ALWP of the EBMT.

Since cord blood transplantation (CBT) has been associated with high graft-versus-leukemia effects and a low incidence of chronic graft-versus-host disease (GVHD), we hypothesized that long-term outcomes might be better in CBT patients than in those given grafts from unrelated donors (UD). Therefore, we performed a landmark study comparing long-term outcomes in acute myeloid leukemia (AML) patients alive and disease-free 2 years after transplantation who received grafts from either CBT or UD. A total of 364 CBT recipients, 2648 UD 10/10 patients and 681 patients given grafts from UD 9/10 were included. Median follow-up was 6.0 years. Five-year leukemia-free survival (LFS) from transplantation was 86% in CBT patients, 84% in UD 10/10 patients (P = 0.36) and 84% in UD 9/10 patients (P = 0.86). On multivariate analysis, donor type had no impact on LFS. Similarly, no impact of donor type was observed on relapse incidence or non-relapse mortality. Factors associated with poorer LFS on multivariate analysis included higher age at transplantation (P < 0.001), male gender (P < 0.001), second complete remission (CR2) versus CR1 (P = 0.05), secondary AML (P = 0.01), antecedent of chronic GVHD (P < 0.001) and poor-risk cytogenetics (P = 0.01). In conclusion, our study shows that long-term outcome for AML patients in CR two years after transplantation is not impacted by donor type.