Variant allele frequencies do not correlate well with myeloblast counts in a clinically validated gene sequencing panel for routine acute myeloid leukemia workup

Diagnosis and management of AML in adults: 2022 recommendations from an international expert panel on behalf of the ELN

The 2010 and 2017 editions of the European LeukemiaNet (ELN) recommendations for diagnosis and management of acute myeloid leukemia (AML) in adults are widely recognized among physicians and investigators. There have been major advances in our understanding of AML, including new knowledge about the molecular pathogenesis of AML, leading to an update of the disease classification, technological progress in genomic diagnostics and assessment of measurable residual disease, and the successful development of new therapeutic agents, such as FLT3, IDH1, IDH2, and BCL2 inhibitors. These advances have prompted this update that includes a revised ELN genetic risk classification, revised response criteria, and treatment recommendations.

International Consensus Classification of Myeloid Neoplasms and Acute Leukemias: integrating morphologic, clinical, and genomic data

The classification of myeloid neoplasms and acute leukemias was last updated in 2016 within a collaboration between the World Health Organization (WHO), the Society for Hematopathology, and the European Association for Haematopathology. This collaboration was primarily based on input from a clinical advisory committees (CACs) composed of pathologists, hematologists, oncologists, geneticists, and bioinformaticians from around the world. The recent advances in our understanding of the biology of hematologic malignancies, the experience with the use of the 2016 WHO classification in clinical practice, and the results of clinical trials have indicated the need for further revising and updating the classification. As a continuation of this CAC-based process, the authors, a group with expertise in the clinical, pathologic, and genetic aspects of these disorders, developed the International Consensus Classification (ICC) of myeloid neoplasms and acute leukemias. Using a multiparameter approach, the main objective of the consensus process was the definition of real disease entities, including the introduction of new entities and refined criteria for existing diagnostic categories, based on accumulated data. The ICC is aimed at facilitating diagnosis and prognostication of these neoplasms, improving treatment of affected patients, and allowing the design of innovative clinical trials.

Distinguishing AML from MDS: a fixed blast percentage may no longer be optimal

Patients with acute myeloid leukemia (AML) have conventionally received more intense therapy than patients with myelodysplastic syndrome (MDS). Although less intense therapies are being used more often in AML, the dichotomy between AML and MDS remains, with the presence of ≥20% myeloblasts in marrow or peripheral blood generally regarded as defining AML. Consequently, patients with 19% blasts are typically ineligible for AML studies, and patients with 21% blasts are ineligible for MDS studies. Here we cite biologic and clinical data to question this practice. Biologically, abnormalities in chromosome 3q26 and mutations in NPM1 and FLT3, regarded as AML associated, also occur in MDS. The genetic signatures of MDS, particularly cases with 10% to 19% blasts (MDS-EB2), resemble those of AML following a preceding MDS (secondary AML). Mutationally, secondary AML appears at least as similar to MDS-EB2 as to de novo AML. Patients presenting with de novo AML but with secondary-type AML mutations seem to have the same poor prognosis associated with clinically defined secondary AML. Seattle data indicate that after accounting for European LeukemiaNet 2017 risk, age, performance status, clinically secondary AML, and treatment including allogeneic transplantation, patients with World Health Organization–defined AML (n = 769) have similar rates of overall survival, event-free survival, and complete remission (CR)/CR with incomplete hematologic recovery as patients with MDS-EB2 (n = 202). We suggest defining patients with 10% to 30% blasts (AML/MDS) as eligible for both AML and MDS studies. This would permit empiric testing of the independent effect of blast percentage on outcome, allow patients access to more therapies, and potentially simplify the regulatory approval process.

Mutational spectrum of de novo NPM1-mutated acute myeloid leukemia patients older than 75 years

AML with mutated NPM1 occurs in all age groups. Yet, the mutational pattern is not extensively studied in the very old, which may hamper appropriate risk assessment. Herein we examined 22 cases of NPM1-mutated de novo AML in patients older than 75, with a median age of 84. All diagnostic samples were sequenced aiming for coverage of the most relevant AML-associated mutations. For comparison with younger patients, we used already published data on several cohorts. A total of 76 mutations including 50 different variants were identified in 16 recurrently mutated AML genes. Compared with younger patients, a significant enrichment of TET2 and SRSF2 was observed, together with a reduced frequency of DNMT3A mutations. Our results indicate that the mutational pattern may be different in the very old as compared to younger patients with NPM1-mutated AML.HighlightsThe mutational spectrum of NPM1-mutated AML in patients above 75 years displays distinct features.A significant enrichment of TET2 and SRSF2 mutations together with a reduced frequency of DNMT3A mutations was observed in the elderly.NPM1 mutation is a secondary event in the development of AML in the very old.