1279 Re-Classification of Acute Myeloid Leukemia Based on Latest World Health Organization & International Consensus Classifications and Its Clinical Impact in a Population-Based Comparative Study

Document Type

Conference Proceeding

Publication Date

3-24-2025

Publication Title

Lab Invest

Keywords

acute myeloid leukemia, adult, clinical outcome, comparative study, conference abstract, consensus, female, genetic risk, high risk population, human, karyotype, major clinical study, male, overall survival, treatment response, World Health Organization

Abstract

Disclosures: Hira Qadir: None; Kedar Inamdar: None; Sharmila Ghosh: None; Yulei Shen: None; Juan Gomez-Gelvez: None; Philip Kuriakose: None; Wei Liu: None Background: Significant changes in acute myeloid leukemia (AML) classification were made in the latest World Health Organization and International Consensus 2022 classifications (WHO22 and ICC22), underpinning the biology of diseases. Whether the classification is in line with clinical outcomes has yet to be fully elucidated. Design: From a pathology database,116 consecutive AML cases with complete data from 1/1/2020 to 12/31/2022 were reclassified based on WHO22 and ICC22. The clinical impact, with a focus on AML-MRC (renamed as AML-MR), was assessed, correlating with ELN2022 genetic risk stratification, post-induction therapy responses and overall survivals. Results: Of 116 AML patients (median age 67, M/F=1:1), 46 (39.7%) were with recurrent genetic abnormalities (RGA), 44 AML-MRC (37.9%), and 26 AML-NOS (22.4%) by WHO2016, most changes in the latter two categories. AML-NOS narrowed down to include 21 patients by WHO22, 17 by ICC22. 54 patients (46.6%) were reclassified as AML-MR by WHO22, including 10 previously classified as AML-NOS (rAML-MR). Most (53.7%, n=29) had both cytogenetic and molecular abnormalities, while 15 had only molecular, 7 had only cytogenetic changes, and 3 neither. Complex karyotype (43.3%, n=26) and ASXL1 mutation (30.2%, n=13) were the most common. Under ICC22, 39 patients (33.6%, also including 10 rAML-MR) were reclassified as AML-MR, 19 patients (16.3%) as AML-TP53, in comparison to WHO22 showing similar genetic composition (data not included). Under WHO22, rAML-MR (n=10) showed significantly higher rate of non-response to treatment than that of AML-NOS (66.6% vs 0%, p=0.0015) while no difference than that of remainder AML-MR (60.0%, p=0.68), with all (100%) concordantly classified in the adverse risk group by ELN2022 (vs 28.6% AML-NOS [p<0.0001] and vs 90.9% remainder AML-MR [p>0.9999]). Of note, while overall survival (OS) was significantly different by WHO22 among AML-NOS, rAML-MR and remainder AML-MR (42 vs undefined vs 704 days, p=0.001), no significance reached between AML-NOS and rAML-MR (p=0.16). Results from ICC22 were similar in addition to that AML-TP53 showed the shortest OS than those with rAML-MR, remainder AML-MR and AML-NOS subgroups (42 vs undefined vs 133 vs 488 days, p=0.0005). Conclusions: While rAML-MR showed significantly worse treatment response and associated with adverse risk by ELN2022, OS was not significantly different from that of AML-NOS. Additional studies are warranted.

Volume

105

Issue

3

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