The pediatric DRI stratified children with AML and ALL into clinically distinct risk groups based on pre-transplantation information
Risk stratification was based on age at transplant, cytogenetics, and disease status including minimal residual disease at transplant
A disease risk index (DRI) that was developed for adults with hematologic malignancy undergoing hematopoietic cell transplant is also being used to stratify children and adolescents by disease risk. Therefore, in this study, we analyzed 2569 patients aged <18 years with acute myeloid (AML; n=1224) or lymphoblastic (ALL; n=1345) leukemia undergoing hematopoietic cell transplant to develop and validate a DRI that may be used to stratify those with AML and ALL by their disease risk. Training and validation subsets for each disease were generated randomly with 1:1 assignment to the subsets and separate prognostic models were derived for each disease. For AML, four risk groups were identified based on age, cytogenetic risk, and disease status including minimal residual disease status at transplantation. The 5-year leukemia-free survival for low (0 points), intermediate (2, 3, 5), high (7, 8), and very high (>8) risk groups were 78%, 53%, 40%, and 25%, respectively, p<0.0001. For ALL, three risk groups were identified based on age and disease status including minimal residual disease status at transplantation. The 5-year leukemia-free survival for low (0 points), intermediate (2-4), and high (≥5) risk groups were 68%, 51%, and 33%, respectively, p<0.0001. We confirmed the risk groups can be applied for overall survival with 5-year survival ranged from 80% to 33% and 73% to 42% for AML and ALL, respectively (p<0.0001). This validated pediatric DRI that includes age and residual disease status can be used to facilitate prognostication and stratification of children with AML and ALL for allogeneic transplantation.