Comparable Outcomes of Matched Sibling Donor and Matched Unrelated Donor Stem Cell Transplantation in Children With Acute Leukemia in Argentina.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) is an effective mode of consolidation therapy for children with high-risk acute leukemia. In high-income countries, match sibling donor (MSD) and match unrelated donor (MUD) HSCT have similar outcomes, but data are scarce in upper-middle-income countries. Our objective was to compare MSD and MUD HSCT outcomes for children with acute leukemia in Argentina. PATIENTS AND METHODS: This was a single-institution retrospective cohort study. We included children with acute leukemia who underwent HSCT with either MSD or MUD between 2014 and 2019. RESULTS: The study included 45 patients who received MSD (n=27) or MUD (n=18) for acute leukemia. Event-free survival was not significantly different between MSD (62.3±10.7%) versus MUD (54.2±15.0%; P=0.54) at 5 years. Similarly, there was no significant difference in 5-year overall survival between MSD (71.9±9.8%) versus MUD (65.1±13.5%; P=0.38). The cumulative incidence of treatment-related mortality (P=0.31), cumulative incidence of relapse (P=0.99), and proportion with acute-graft-versus-host disease (P=0.76) and chronic-graft-versus-host disease (P=0.68) were also not significantly different. CONCLUSIONS: In Argentina, we did not show significant differences in outcomes between MSD and MUD HSCT for children with high-risk leukemia. Future work should focus on strategies to reduce the relapse risk in children with high-risk leukemia in upper-middle-income countries.