Persistence of minimal residual disease assessed by multiparameter flow cytometry is highly prognostic in younger patients with acute myeloid leukemia

BACKGROUND: Predicting outcomes for patients with acute myeloid leukemia (AML) on the basis of pretreatment predictors has been the cornerstone of management. Posttreatment prognostic factors are increasingly being evaluated. METHODS: ) and idarubicin-based induction chemotherapy and achieved remission, 186 were assessed for minimal residual disease (MRD) with an 8-color multiparameter flow cytometry panel performed on bone marrow specimens with a sensitivity of 0.1% or higher. RESULTS: One hundred sixty-six patients had samples available 1 to 2 months after induction at the time of complete remission (CR), and 79% became negative for MRD, with an MRD-negative status associated with an improvement in relapse-free survival (RFS; P = .0002) and overall survival (OS; P = .0002). One hundred sixteen were evaluated for their MRD status during consolidation, and 86% were negative, with an MRD-negative status associated with a significant improvement in RFS (P < .0001) and OS (P < .0001). Sixty-nine patients were evaluated for their MRD status after completion of all therapy, and 84% were negative, with an MRD-negative status associated with an improvement in RFS (P < .0001) and OS (P < .0001). In a multivariate analysis including age, cytogenetics, response (CR vs CR with incomplete platelet recovery/incomplete blood count recovery), and MRD, achieving an MRD-negative status was the most important independent predictor of RFS and OS at response (P = .008 and P = .0008, respectively), during consolidation (P < .0001 for both), and at the completion of therapy (P < .0001 and P = .002, respectively). CONCLUSIONS: Achieving an MRD-negative status according to multiparameter flow cytometry is associated with a highly significant improvement in the outcomes of younger patients with AML receiving cytosine arabinoside plus idarubicin-based induction and consolidation regimens. Cancer 2017;123:426-435.