ELN2017 risk stratification improves outcome prediction when applied to the prospective GIMEMA AML1310 protocol

Abstract

The 2017 version of the European LeukemiaNet (ELN) recommendations, by integrating cytogenetics and mutational status of specific genes, divides patients with acute myeloid leukemia into 3 prognostically distinct risk categories: favorable (ELN2017-FR), intermediate (ELN2017-IR), and adverse (ELN2017-AR). We performed a post hoc analysis of the GIMEMA (Gruppo Italiano Malattie EMatologiche dell'Adulto) AML1310 trial to investigate the applicability of the ELN2017 risk stratification to our study population. In this trial, after induction and consolidation, patients in complete remission were to receive an autologous stem cell transplant (auto-SCT) if categorized as favorable risk or an allogeneic stem cell transplant (allo-SCT) if adverse risk. Intermediate-risk patients were to receive auto-SCT or allo-SCT based on the postconsolidation levels of measurable residual disease as measured by using flow cytometry. Risk categorization was originally conducted according to the 2009 National Comprehensive Cancer Network recommendations. Among 500 patients, 445 (89%) were reclassified according to the ELN2017 criteria: ELN2017-FR, 186 (41.8%) of 455; ELN2017-IR, 179 (40.2%) of 445; and ELN2017-AR, 80 (18%) of 455. In 55 patients (11%), ELN2017 was not applicable. Two-year overall survival (OS) was 68.8%, 51.3%, 45.8%, and 42.8% for the ELN2017-FR, ELN2017-IR, ELN2017-not classifiable, and ELN2017-AR groups, respectively (P < .001). When comparing the 2 different transplant strategies in each ELN2017 risk category, a significant benefit of auto-SCT over allo-SCT was observed among ELN2017-FR patients (2-year OS of 83.3% vs 66.7%; P = .0421). The 2 transplant procedures performed almost equally in the ELN2017-IR group (2-year OS of 73.9% vs 70.8%; P = .5552). This post hoc analysis of the GIMEMA AML1310 trial confirms that the ELN2017 classification is able to accurately discriminate patients with different outcomes and who may benefit from different transplant strategies. This trial was registered as EudraCT number 2010-023809-36 and at www.clinicaltrials.gov as #NCT01452646.

© 2022 by The American Society of Hematology. Licensed under Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0), permitting only noncommercial, nonderivative use with attribution. All other rights reserved.

Figures

Graphical abstract

Figure 1.

Spine plot for each NCCN showing the proportion of adverse (red), intermediate (blue), and favorable (light green) risk. A small proportion of NCCN2009 patients (75 of 188 [39%]) remained classified as high risk according to ELN2017. A high proportion of NCCN2009-PR cases were redistributed across all ELN2017 risk groups, with 38 (20.2%), 55 (29.2%), and 20 (10.6%) of 188 NCCN2009-PR patients now being reclassified as ELN2017-FR, ELN2017-IR, and ELN2017-NC, respectively. At variance, 132 (95.6%) of 138 NCCN-FR cases and 120 (68.9%) of 174 NCCN-IR cases remained classified as ELN2017-FR and ELN2017-IR, respectively.

Figure 2.

Patient outcome according to ELN2017 risk stratification and FLT3/NPM1 gene interactions. (A) Two-year OS was 68.8%, 51.3%, 42.8%, and 45.8% for patients belonging to the ELN2017-FR, ELN2017-IR, ELN2017-AR, and ELN2017-NC categories, respectively. (B) Two-year DFS was 59.9%, 54.2%, 45.5%, and 40.3% for the ELN2017-FR, ELN2017-IR, ELN2017-AR, and ELN2017-NC patients.

Figure 3.

Correlation between postconsolidation strategy and outcome for each ELN2017 risk category. (A) Benefit of auto-SCT in the ELN2017-FR category (2-year OS of 83.3% vs 66.7% for auto-SCT vs allo-SCT). (B) Almost equal performance of allo-SCT and auto-SCT in the ELN2017-IR category (2-year OS of 70.8% and 73.9%, for allo-SCT and auto-SCT, respectively).