Concordance in measurable residual disease result after first and second induction cycle in acute myeloid leukemia: An outcome- and cost-analysis

Combination of pre-transplant flow cytometry, WT1 expression, and NGS for MRD monitoring is potent in predicting the prognosis of AML receiving allogeneic transplantation

Minimal residual disease (MRD) monitoring has been demonstrated to important in predicting prognosis in acute myeloid leukemia (AML) receiving allogeneic hematopoietic stem cell transplantation (allo-HSCT), but the ideal time point and method remain unclear. Our study compared the prognostic value of multiparameter flow cytometry (MFC)-based and WT1 expression-based MRD a month before allo-HSCT [HSCT(-1 m)] and after allo-HSCT [HSCT(+ 1 m)], as well as next generation sequencing (NGS)-based MRD at HSCT(-1 m), HSCT(+ 1 m), 3 and 6 months after allo-HSCT [HSCT(+ 3 m) and HSCT(+ 6 m)] among 47 AML patients undergoing allo-HSCT. The MRD status by all the methods at HSCT(-1 m) was proved as a superior indicator with prognostic significance for disease progression, compared to that at HSCT(+ 1 m). For the NGS-based MRD, HSCT(+ 6 m) seemed to be the optimal detection time point, as supported by the optimal prognostic discrimination capability and the relatively high sensitivity for disease progression prediction. Moreover, our data showed that each individual method had some limitations in predicting prognosis; however, pre-transplant MRD monitoring by the combination of MFC, WT1 and NGS could greatly increase the sensitivity (100%) of identifying disease progression and greatly improve prognostic stratification. Our study may provide insights into the optimal time point and methodology for MRD monitoring in AML following allo-HSCT.

The Evolution of Treatment Policies and Outcomes for Patients Aged 60 and Older with Acute Myeloid Leukemia: A Population-Based Analysis over Two Decades

BACKGROUND

Acute myeloid leukemia (AML) is a malignancy of the bone marrow with a median age at diagnosis of 70 years. AML is difficult to treat, especially in older patients, among whom outcomes have historically been poor. Over the last two decades, a greater understanding of the molecular mechanisms of the pathology has led to the development of new drugs and multiple updates to treatment guidelines.

METHODS

A population-based retrospective cohort study was conducted for all patients aged 60 and older who were newly diagnosed with AML (n = 370) as defined by the European Leukemia Net 2022 criteria in Friesland, a Dutch province, between 2005 and 2023.

RESULTS

In this cohort of patients with a median age of 73 years, complete bone marrow analysis to classify the AML according to ELN increased in time from 49% (2005-2011) to 86% (2022-2023). The rate of patients receiving antileukemic therapy increased over time (2005-2011: 19%; 2012-2016: 64%; 2017-2021: 75%; 2022-2023: 74%), mainly driven by the introduction of hypomethylating agents. Over these time periods, the use of intensive chemotherapy (13%, 27%, 27%, and 5%) and rates of stem cell transplantation (3%, 9%, 27%, and 14%) underwent similar development as more patients were deemed eligible for these interventions from 2012 onwards, but usage declined again after the introduction of venetoclax in 2022. The median overall survival was 3.7, 7.3, 8.0, and 9.4 months over the four time periods, respectively.

CONCLUSIONS

Our study demonstrates how outcomes of patients with newly diagnosed AML aged 60 and older improved over the last two decades.

Understanding differential technologies for detection of MRD and how to incorporate into clinical practice

Patient- and leukemia-specific factors assessed at diagnosis classify patients with acute myeloid leukemia (AML) in risk categories that are prognostic for outcome. The induction phase with intensive chemotherapy in fit patients aims to reach a complete remission (CR) of less than 5% blasts in bone marrow by morphology. To deepen and sustain the response, induction is followed by consolidation treatment. This postremission treatment of patients with AML is graduated in intensity based on this favorable, intermediate, or adverse risk group classification as defined in the European Leukemia Network (ELN) 2022 recommendations. The increment of evidence that measurable residual disease (MRD) after induction can be superimposed on risk group at diagnosis is instrumental in tailoring further treatment accordingly. Several techniques are applied to detect MRD such as multiparameter flow cytometry (MFC), quantitative (digital) polymerase chain reaction (PCR), and next-generation sequencing. The clinical implementation of MRD and the technique used differ among institutes, leading to the accumulation of a wide range of data, and therefore harmonization is warranted. Currently, evidence for MRD guidance is limited to the time point after induction using MFC or quantitative PCR for NPM1 and core binding factor abnormalities in intermediate-risk patients. The role of MRD in targeted or nonintensive therapies needs to be clarified, although some data show improved survival in patients achieving CR-MRD negativity. Potential application of MRD for selection of conditioning before stem cell transplantation, monitoring after consolidation, and use as an intermediate end point in clinical trials need further evaluation.

Advances in Acute Myeloid Leukemia Classification, Prognostication and Monitoring by Flow Cytometry

Although final classification of acute myeloid leukemia (AML) integrates morphologic, cytogenetic, and molecular data, flow cytometry remains an essential component of modern AML diagnostics. Here, we review the current role of flow cytometry in the classification, prognostication, and monitoring of AML. We cover immunophenotypic features of key genetically defined AML subtypes and their effects on biological and clinical behaviors, review clinically tractable strategies to differentiate leukemias with ambiguous immunophenotypes more accurately and discuss key principles of standardization for measurable residual disease monitoring. These advances underscore flow cytometry's continued growth as a powerful diagnostic, management, and discovery tool.