Myeloablative unrelated cord blood transplantation in adolescents and young adults with acute leukemia

ABSTRACT Outcomes for adolescents and young adults (AYA) with leukemia differ from other age groups but are still underrepresented in clinical research. The aim of this study was to analyze outcomes of umbilical cord blood transplant (UCBT) in AYA with acute leukemia reported to Eurocord/EBMT. Patients (n=504) had acute lymphoblastic (59%) or myeloid leukemia (41%), were aged 15-25 years, and received UCBT after myeloablative conditioning regimens between 2004 and 2016. Primary endpoint was 3-year overall survival (OS). Median follow-up was 3.9 years. Transplant was single in 58% and double UCBT in 42%. Three-year OS was 45% and leukemia free survival (LFS) was 41%. Cumulative incidence functions (CIF) of non-relapse mortality (NRM) and relapse were 31% and 28%, respectively. CIF of acute GVHD grade II-IV at day-100 was 28%. Three-year CIF of chronic GVHD was 25%. In adjusted analysis, better disease status at UCBT (HR 2.74, p The risk of acute GVHD grade II-IV increased with the use of double UCBT (HR 1.65, p =0.02) and decreased with more recent transplantation period (HR 0.65, p=0.02) and ATG use (HR 0.55, p =0.01). Outcomes of AYA UCBT improved in more recent years becoming comparable to pediatric results. Demonstrating the feasibility of UCBT in AYA facilitates stem cell source selection and provides the basis for future prospective studies.