Trends in patient outcome over the past two decades following allogeneic stem cell transplantation for acute myeloid leukaemia: an ALWP/EBMT analysis

Background: Outcomes for patients with acute myeloid leukaemia (AML) undergoing allogeneic stem cell transplantation (allo-SCT) have significantly improved in recent years. Objectives: To assess the incremental improvement of transplanted AML patients in the last two decades. Methods: Patients included in this analysis were adult AML patients who underwent allo-SCT from an HLA-matched sibling donor (MSD) or HLA-matched unrelated donor (MUD) in first remission. Patient outcomes were assessed between three cohorts according to the year of transplant (1993–2002, 2003–2007 and 2008–2012). Results: The analysis comprised a total of 20 187 patients of whom 4763 were transplanted between 1993 and 2002, 5835 in 2003 and 2007, and 9589 in 2008 and 2012. In multivariate analysis, leukaemia-free survival (LFS) rates were significantly improved in more recently transplanted patients compared to patients transplanted in 1993–2002 [Hazard ratio (HR) = 0.84, confidence interval (CI) 95%, 0.77–0.92; P = 0.003], a benefit which also extended to improved overall survival (OS; HR = 0.8, CI 95%, 0.73–0.89; P < 0.0001), and decreased nonrelapse mortality (NRM) rates (HR = 0.65, CI 95%, 0.56–0.75; P < 0.0001). Subset analysis revealed that in MSD, the rates of LFS, NRM and OS significantly improved in patients in the more recent cohort with similar results also seen in MUD. Finally, the incidence of acute graft-versus-host disease (GVHD) was significantly reduced leading to improved GVHD-free/relapse-free survival (GRFS) rates in more recently transplanted patients. Conclusion: Outcome of allo-SCT for AML patients has markedly improved in the last two decades owing to decreased nonrelapse mortality and improved rates of leukaemia-free survival resulting in significantly longer survival.