Is the adult EBMT risk score valid and relevant for hematopoietic stem cell transplantation in children acute leukemia?

The EBMT risk score, incorporating five factors to estimate the risks associated with haematopoietic stem cell transplantation (HSCT) in adult patients, has not been validated in children. This study aims to assess this score in 9447 children undergoing allogeneic HSCT for acute lymphoblastic or myeloid leukemia (ALL/AML) between 2010 and 2021. Risk factors were coded according to the original EBMT score. In both ALL (n = 5774) and AML (n = 3673), only disease status and the time from diagnosis to HSCT significantly impacted all the outcomes in the multivariable analysis. The combination of female donors and male recipients did not affect overall survival (OS), relapse incidence (RI), non-relapse mortality (NRM), and leukemia-free survival (LFS). Additionally, the prognostic impact of donor type was not evident; when viewed as two modalities, the impact of MSD versus non-MSD on different outcomes in ALL was inconsistent with those observed in AML. Consequently, in both ALL and AML, scores ranging from 3 to 5 significantly affected all outcomes, whereas a score of 2 did not significantly impact NRM or RI in AML. Therefore, this analysis demonstrates that the adult EBMT risk score is not entirely reliable in children with acute leukemia, highlighting the need for a new pediatric-specific prognostic score.