2021 Update on MRD in acute myeloid leukemia: a consensus document from the European LeukemiaNet MRD Working Party.
ABSTRACT: Measurable residual disease (MRD) is an important biomarker in acute myeloid leukemia (AML) that is used for prognostic, predictive, monitoring, and efficacy-response assessments. The European LeukemiaNet (ELN) MRD Working Party evaluated standardization and harmonization of MRD in an ongoing manner and has updated the 2018 ELN MRD recommendations based on significant developments in the field. New and revised recommendations were established during in-person and online meetings, and a 2-stage Delphi poll was conducted to optimize consensus. All recommendations are graded by levels of evidence and agreement. Major changes include technical specifications for next-generation sequencing-based MRD testing and integrative assessments of MRD irrespective of technology. Other topics include use of MRD as a prognostic and surrogate end point for drug testing; selection of the technique, material, and appropriate time points for MRD assessment; and clinical implications of MRD assessment. In addition to technical recommendations for flow- and molecular-MRD analysis, we provide MRD thresholds and define MRD response, and detail how MRD results should be reported and combined if several techniques are used. MRD assessment in AML is complex and clinically relevant, and standardized approaches to application, interpretation, technical conduct, and reporting are of critical importance.
Project description:Measurable residual disease (MRD; previously termed minimal residual disease) is an independent, postdiagnosis, prognostic indicator in acute myeloid leukemia (AML) that is important for risk stratification and treatment planning, in conjunction with other well-established clinical, cytogenetic, and molecular data assessed at diagnosis. MRD can be evaluated using a variety of multiparameter flow cytometry and molecular protocols, but, to date, these approaches have not been qualitatively or quantitatively standardized, making their use in clinical practice challenging. The objective of this work was to identify key clinical and scientific issues in the measurement and application of MRD in AML, to achieve consensus on these issues, and to provide guidelines for the current and future use of MRD in clinical practice. The work was accomplished over 2 years, during 4 meetings by a specially designated MRD Working Party of the European LeukemiaNet. The group included 24 faculty with expertise in AML hematopathology, molecular diagnostics, clinical trials, and clinical medicine, from 19 institutions in Europe and the United States.
Project description:The first edition of the European LeukemiaNet (ELN) recommendations for diagnosis and management of acute myeloid leukemia (AML) in adults, published in 2010, has found broad acceptance by physicians and investigators caring for patients with AML. Recent advances, for example, in the discovery of the genomic landscape of the disease, in the development of assays for genetic testing and for detecting minimal residual disease (MRD), as well as in the development of novel antileukemic agents, prompted an international panel to provide updated evidence- and expert opinion-based recommendations. The recommendations include a revised version of the ELN genetic categories, a proposal for a response category based on MRD status, and criteria for progressive disease.
Project description:The revised 2017 European LeukemiaNet (ELN) recommendations for genetic risk stratification of acute myeloid leukemia have been widely adopted, but have not yet been validated in large cohorts of AML patients. We studied 1116 newly diagnosed AML patients (age range, 18-86 years) who had received induction chemotherapy. Among 771 patients not selected by genetics, the ELN-2017 classification re-assigned 26.5% of patients into a more favorable or, more commonly, a more adverse-risk group compared with the ELN-2010 recommendations. Forty percent of the cohort, and 51% of patients ?60 years, were classified as adverse-risk by ELN-2017. In 599 patients <60 years, estimated 5-year overall survival (OS) was 64% for ELN-2017 favorable, 42% for intermediate-risk and 20% for adverse-risk patients. Among 517 patients aged ?60 years, corresponding 5-year OS rates were 37, 16, and 6%. Patients with biallelic CEBPA mutations or inv(16) had particularly favorable outcomes, while patients with mutated TP53 and a complex karyotype had especially poor prognosis. DNMT3A mutations associated with inferior OS within each ELN-2017 risk group. Our results validate the prognostic significance of the revised ELN-2017 risk classification in AML patients receiving induction chemotherapy across a broad age range. Further refinement of the ELN-2017 risk classification is possible.
Project description:Patients with acute myeloid leukemia (AML) harboring FLT3 internal tandem duplications (ITDs) have poor outcomes, in particular AML with a high (?0.5) mutant/wild-type allelic ratio (AR). The 2017 European LeukemiaNet (ELN) recommendations defined 4 distinct FLT3-ITD genotypes based on the ITD AR and the NPM1 mutational status. In this retrospective exploratory study, we investigated the prognostic and predictive impact of the NPM1/FLT3-ITD genotypes categorized according to the 2017 ELN risk groups in patients randomized within the RATIFY trial, which evaluated the addition of midostaurin to standard chemotherapy. The 4 NPM1/FLT3-ITD genotypes differed significantly with regard to clinical and concurrent genetic features. Complete ELN risk categorization could be done in 318 of 549 trial patients with FLT3-ITD AML. Significant factors for response after 1 or 2 induction cycles were ELN risk group and white blood cell (WBC) counts; treatment with midostaurin had no influence. Overall survival (OS) differed significantly among ELN risk groups, with estimated 5-year OS probabilities of 0.63, 0.43, and 0.33 for favorable-, intermediate-, and adverse-risk groups, respectively (P < .001). A multivariate Cox model for OS using allogeneic hematopoietic cell transplantation (HCT) in first complete remission as a time-dependent variable revealed treatment with midostaurin, allogeneic HCT, ELN favorable-risk group, and lower WBC counts as significant favorable factors. In this model, there was a consistent beneficial effect of midostaurin across ELN risk groups.
Project description:The European LeukemiaNet (ELN) recommendations for diagnosis and management of acute myeloid leukemia (AML) have become an important tool to assess patients' prognosis and guide treatment. We tested the prognostic impact of the 2017 ELN classification in a large cohort of 863 AML patients aged <60 years similarly treated on Cancer and Leukemia Group B/Alliance for Clinical Trials in Oncology studies. Based on multivariable models within each ELN genetic-risk group, we identified additional gene mutations that may refine the 2017 ELN risk classification. BCOR- or SETBP1-mutated favorable-risk patients with non-core-binding factor AML and IDH-mutated adverse-risk patients had intermediate-risk outcomes. Outcomes of NPM1/WT1 co-mutated patients and those of ZRSR2-mutated patients resembled outcome of adverse-risk patients. Moreover, FLT3-ITD<sup>high</sup> allelic ratio conferred adverse rather than intermediate-risk irrespective of the NPM1 mutation status, and DNMT3A mutations associated with very poor survival. Application of these refinements reclassified 9% of current favorable-risk patients and 53% of current intermediate-risk patients to the adverse-risk group, with similar poor survival as current adverse-risk patients. Furthermore, 4% of current favorable-risk patients and 9% of adverse-risk patients were reclassified to the intermediate-risk group.
Project description:BACKGROUND:The revised 2017 European LeukemiaNet (ELN) classification (ELN-2017) of acute myeloid leukemia (AML) divides patients into 3 prognostic risk categories, with additional factors such as the fms-like tyrosine kinase 3 (FLT3)-internal tandem duplication (ITD) allele ratio (AR) considered for risk stratification. To the best of the authors' knowledge, the prognostic usefulness of ELN-2017 in comparison with ELN-2010 in younger patients with AML has not been validated to date. METHODS:The authors performed a retrospective study on patients aged <60 years who received idarubicin plus cytarabine (IA)-based induction chemotherapy for newly diagnosed AML. RESULTS:According to ELN-2017 criteria, the number of patients in the favorable (Fav), intermediate (Int), and adverse (Adv) risk categories was 192 patients (27%), 331 patients (46%), and 192 patients (27%), respectively. Overall survival probabilities at 5 years in the Fav, Int, and Adv groups were 57%, 37%, and 18%, respectively. In comparison, the 5-year overall survival probabilities in the Fav (169 patients), intermediate (IR)-1 (80 patients), IR-2 (306 patients), and Adv (160 patients) ELN-2010 categories were 59%, 32%, 40%, and 14%, respectively. Although ELN-2010 historically distinguishes prognosis into IR-1 and IR-2 categories in younger patients, this difference was nullified in the current study cohort. When comparing patients with a low FLT3-ITD AR with those with a high FLT3-ITD AR, no significant differences in survival were noted among patients with nucleophosmin 1 (NPM1)-mutated AML (P = .28) or wild-type NPM1 (P = .35), and in those treated with IA alone (P = .79) or those treated with IA and a FLT3 inhibitor (P = .10). CONCLUSIONS:The ELN-2017 more accurately distinguishes prognosis in patients with newly diagnosed AML. The lack of prognostic significance for the FLT3-ITD AR needs further evaluation in different treatment settings.
Project description:We evaluated the prognostic significance of a modified European LeukemiaNet (ELN) classification for patients with acute myelogenous leukemia (AML) undergoing hematopoietic stem cell transplantation (HSCT) while in first complete remission (CR1). We analyzed 464 AML patients with matched related (n = 211, 45.5%), matched unrelated (n = 176, 37.9%), and mismatched donors (n = 77, 16.6%). Patients were classified into 4 modified ELN risk groups (favorable, intermediate-I, intermediate-II, and adverse) separately for 354 patients age < 60 years and 110 patients age ? 60 years. In this modified version of ELN classification, patients with normal cytogenetic were classified by FLT3-ITD mutational status: favorable risk if FLT3-ITDwild and intermediate-I if FLT3-ITDmut. The best outcomes occurred in the ELN favorable and intermediate-II groups in younger AML patients and in the favorable and intermediate-I groups in older AML patients. Older AML patients had worse transplant outcomes within each modified ELN risk group except intermediate-I when compared with younger patients; leukemia-free survival at 3 years was 67.8% versus 49.8% in favorable, 53.4% versus 50.7% in intermediate-I, 65.7% versus 20.2% in intermediate-II, and 44.6% versus 23.8% in adverse group younger and older patients, respectively. Among lesion-specific abnormalities, del5q/-5 and abnl(17p) had the worse transplant outcomes, with 3-year leukemia-free survival rates of 18.4% and 20% in younger CR1 patients. In conclusion, the modified ELN prognostic classification developed for chemotherapy outcomes also identifies prognostic groups for HSCT, which is useful for a selection of patients for post-transplant strategies to improve outcomes.
Project description:<h4>Purpose</h4>To determine the frequency of TET2 mutations, their associations with clinical and molecular characteristics and outcome, and the associated gene- and microRNA-expression signatures in patients with primary cytogenetically normal acute myeloid leukemia (CN-AML).<h4>Patients and methods</h4>Four-hundred twenty-seven patients with CN-AML were analyzed for TET2 mutations by polymerase chain reaction and direct sequencing and for established prognostic gene mutations. Gene- and microRNA-expression profiles were derived using microarrays.<h4>Results</h4>TET2 mutations, found in 23% of patients, were associated with older age (P < .001) and higher pretreatment WBC (P = .04) compared with wild-type TET2 (TET2-wt). In the European LeukemiaNet (ELN) favorable-risk group (patients with CN-AML who have mutated CEBPA and/or mutated NPM1 without FLT3 internal tandem duplication [FLT3-ITD]), TET2-mutated patients had shorter event-free survival (EFS; P < .001) because of a lower complete remission (CR) rate (P = .007), and shorter disease-free survival (DFS; P = .003), and also had shorter overall survival (P = .001) compared with TET2-wt patients. TET2 mutations were not associated with outcomes in the ELN intermediate-I-risk group (CN-AML with wild-type CEBPA and wild-type NPM1 and/or FLT3-ITD). In multivariable models, TET2 mutations were associated with shorter EFS (P = .004), lower CR rate (P = .03), and shorter DFS (P = .05) only among favorable-risk CN-AML patients. We identified a TET2 mutation-associated gene-expression signature in favorable-risk but not in intermediate-I-risk patients and found distinct mutation-associated microRNA signatures in both ELN groups.<h4>Conclusion</h4>TET2 mutations improve the ELN molecular-risk classification in primary CN-AML because of their adverse prognostic impact in an otherwise favorable-risk patient subset. Our data suggest that these patients may be candidates for alternative therapies.
Project description:<h4>Purpose</h4>To evaluate the prognostic significance of the international European LeukemiaNet (ELN) guidelines for reporting genetic alterations in acute myeloid leukemia (AML).<h4>Patients and methods</h4>We analyzed 1,550 adults with primary AML, treated on Cancer and Leukemia Group B first-line trials, who had pretreatment cytogenetics and, for cytogenetically normal patients, mutational status of NPM1, CEBPA, and FLT3 available. We compared complete remission (CR) rates, disease-free survival (DFS), and overall survival (OS) among patients classified into the four ELN genetic groups (favorable, intermediate-I, intermediate-II, adverse) separately for 818 younger (age < 60 years) and 732 older (age ? 60 years) patients.<h4>Results</h4>The percentages of younger versus older patients in the favorable (41% v 20%; P < .001), intermediate-II (19% v 30%; P < .001), and adverse (22% v 31%; P < .001) genetic groups differed. The favorable group had the best and the adverse group the worst CR rates, DFS, and OS in both age groups. Both intermediate groups had significantly worse outcomes than the favorable but better than the adverse group. Intermediate-I and intermediate-II groups in older patients had similar outcomes, whereas the intermediate-II group in younger patients had better OS but not better CR rates or DFS than the intermediate-I group. The prognostic significance of ELN classification was confirmed by multivariable analyses. For each ELN group, older patients had worse outcomes than younger patients.<h4>Conclusion</h4>The ELN classification clearly separates the genetic groups by outcome, supporting its use for risk stratification in clinical trials. Because they have different proportions of genetic alterations and outcomes, younger and older patients should be reported separately when using the ELN classification.
Project description:Measurable residual disease (MRD) in AML, assessed by multicolor flow cytometry, is an important prognostic factor. Progenitors are key populations in defining MRD, and cases of MRD involving these progenitors are calculated as percentage of WBC and referred to as white blood cell MRD (WBC-MRD). Two main compartments of WBC-MRD can be defined: (1) the AML part of the total primitive/progenitor (CD34+, CD117+, CD133+) compartment (referred to as primitive marker MRD; PM-MRD) and (2) the total progenitor compartment (% of WBC, referred to as PM%), which is the main quantitative determinant of WBC-MRD. Both are related as follows: WBC-MRD = PM-MRD × PM%. We explored the relative contribution of each parameter to the prognostic impact. In the HOVON/SAKK study H102 (300 patients), based on two objectively assessed cut-off points (2.34% and 10%), PM-MRD was found to offer an independent prognostic parameter that was able to identify three patient groups with different prognoses with larger discriminative power than WBC-MRD. In line with this, the PM% parameter itself showed no prognostic impact, implying that the prognostic impact of WBC-MRD results from the PM-MRD parameter it contains. Moreover, the presence of the PM% parameter in WBC-MRD may cause WBC-MRD false positivity and WBC-MRD false negativity. For the latter, at present, it is clinically relevant that PM-MRD ≥ 10% identifies a patient sub-group with a poor prognosis that is currently classified as good prognosis MRD<sup>negative</sup> using the European LeukemiaNet 0.1% consensus MRD cut-off value. These observations suggest that residual disease analysis using PM-MRD should be conducted.