The Prognostic Value of Minimal Residual Disease Assessed During the Remission Induction Stage in Acute Myeloid Leukemia Patients

BACKGROUND. The assessment of minimal residual disease (MRD) in acute myeloid leukemias (AML) is an important tool for predicting treatment outcomes, especially in patients with favorable and intermediate cytogenetic/molecular risk. MRD assessed by multicolor flow cytometry (MFC) allows to identify patients with high relapse risk. MRD-positive status after the second chemotherapy cycle is associated with low long-term survival rates. AIM. To assess the long-term therapy outcomes in AML patients with vs. without MRD measured during the remission induction stage. MATERIALS & METHODS. The study enrolled 73 AML patients treated at the National Research Center for Hematology from 2017 to 2021. They were aged 17 to 58 years (median 37 years); there were 45 women and 28 men. Patients were treated with the ‘ОМЛ-17’ and ‘mОМЛ-17’ regimens. MRD was measured by MFC after the first and second induction chemotherapy cycles. RESULTS. After 2 induction cycles, complete remission was achieved in 89.1 % (65/73) of patients. After the first cycle, MRD-negative status was confirmed in 66.7 % (38/57) of patients and after the second one it was documented in 74.6 % (44/59) of patients. MRD-positive status after the first and the second chemotherapy cycles was associated with the lowest rates of overall and disease-free survival as well as higher relapse risk. Multivariate analysis confirmed MRD-negative status in the period of complete remission to be a key factor in reducing the relapse risk and mortality. CONCLUSION. The present study demonstrates that MRD status at two end-points of the program AML therapy (after the first and second induction cycles) serves as an optimal basis for predicting treatment outcomes. MRD-positive status at each of these end-points is associated with a high relapse risk and worse survival. Therefore, MRD monitoring during the remission induction stage is a powerful tool for personalizing the therapy and improving the prognosis of AML patients.