Prognostic significance of measurable residual disease based on multiparameter flow cytometry in childhood acute myeloid leukemia.

Objectives: To study the prognostic value of measurable residual disease (MRD) for childhood acute myeloid leukemia (AML) by analyzing MRD-guided risk stratification therapy.

Methods: A total of 93 children with AML were prospectively enrolled in this study. Chemotherapy with the 2015-AML-03 regimen was completed according to the risk stratification determined by genetic abnormality at initial diagnosis and MRD and bone marrow cytology after induction therapy I. Multiparameter flow cytometry was used to dynamically monitor MRD and analyze the prognostic effect of MRD on 3-year cumulative incidence of recurrence (CIR) rate, event-free survival (EFS) rate, and overall survival (OS) rate.

Results: The 93 children with AML had a 3-year CIR rate of 48%±6%, a median time to recurrence of 11 months (range 2-32 months), a 3-year OS rate of 65%±6%, and a 3-year EFS rate of 50%±5%. After induction therapy I and intensive therapy I, the MRD-positive children had a significantly higher 3-year CIR rate and significantly lower 3-year EFS and OS rates than the MRD-negative children (<0.05). There were no significant differences in 3-year CIR, EFS, and OS rates between the MRD-positive children with a low risk at initial diagnosis and the MRD-negative children after adjustment of chemotherapy intensity (>0.05). The multivariate analysis showed that positive MRD after intensive treatment I was a risk factor for 3-year OS rate in children with AML (<0.05).

Conclusions: MRD has predictive value for the prognosis of children with AML. Based on the MRD-guided risk stratification therapy, reasonable application of chemotherapy may improve the overall prognosis of children with AML.