Measurable residual disease recurrence as early warning of relapse in acute myeloid leukemia

Abstract

To investigate the clinical features and outcomes of measurable residual disease recurrence (MRD-R) by multiparameter flow cytometric in acute myeloid leukemia (AML). We retrospectively analyzed clinical characteristic, residual disease status and outcomes of 767 newly diagnosed AML patients achieving complete remission within two cycles of induction at our center. Totally, 171 (22.3%) patients experienced MRD-R during follow-up. Patients with MRD-R had inferior outcomes compared to those without MRD-R, with 3-year cumulative incidence of morphologic relapse (CIR), relapse-free survival (RFS) and overall survival (OS) at 63.6% vs. 30.6% (P<0.001), 13.9% vs. 67.2% (P<0.001) and 39.0% vs. 79.2% (P<0.001), respectively. The outcomes for patients from the minute (<0.1%) and overt (≥0.1%) MRD-R groups were comparable, with 3-year CIR, RFS and OS at 65.2% vs. 68.2% (P=0.76), 28.9% vs. 27.5% (P=0.85), and 44.8% vs. 38.9% (P=0.39). Early intervention at the time of MRD-R postponed morphologic relapse (MOR-R) with median interval from MRD-R to MOR-R at 4.2 months vs. 1.7 months without intervention (P=0.033). Taken together, MRD-R indicated higher incidence of relapse and poorer outcomes and it could serve as an early warning event for relapse in clinical practice. Early intervention could delay relapse, thereby creating a time window for transplantation.