Comparison of the 2022 world health organization classification and international consensus classification in myelodysplastic syndromes/neoplasms.

In 2022, two novel classification systems for myelodysplastic syndromes/neoplasms (MDS) have been proposed: the International Consensus Classification (ICC) and the 2022 World Health Organization (WHO-2022) classification. These two contemporary systems exhibit numerous shared features but also diverge significantly in terminology and the definition of new entities. Thus, we retrospectively validated the ICC and WHO-2022 classification and found that both systems promoted efficient segregation of this heterogeneous disease. After examining the distinction between the two systems, we showed that a peripheral blood blast percentage ≥ 5% indicates adverse survival. Identifying MDS/acute myeloid leukemia with MDS-related gene mutations or cytogenetic abnormalities helps differentiate survival outcomes. In MDS, not otherwise specified patients, those diagnosed with hypoplastic MDS and single lineage dysplasia displayed a trend of superior survival compared to other low-risk MDS patients. Furthermore, the impact of bone marrow fibrosis on survival was less pronounced within the ICC framework. Allogeneic transplantation appears to improve outcomes for patients diagnosed with MDS with excess blasts in the ICC. Therefore, we proposed an integrated system that may lead to the accurate diagnosis and advancement of future research for MDS. Prospective studies are warranted to validate this refined classification.

Dysregulated immune and metabolic pathways are associated with poor survival in adult acute myeloid leukemia with CEBPA bZIP in-frame mutations.

Acute myeloid leukemia (AML) with CEBPA bZIP in-frame mutations (CEBPAbZIP-inf) is classified within the favorable-risk group by the 2022 European LeukemiaNet (ELN-2022). However, heterogeneous clinical outcomes are still observed in these patients. In this study, we aimed to investigate the mutation profiles and transcriptomic patterns associated with poor outcomes in patients with CEBPAbZIP-inf. One hundred and thirteen CEBPAbZIP-inf patients were identified in a cohort of 887 AML patients homogeneously treated with intensive chemotherapy. Concurrent WT1 or DNMT3A mutations significantly predicted worse survival in AML patients with CEBPAbZIP-inf. RNA-sequencing analysis revealed an enrichment of interferon (IFN) signaling and metabolic pathways in those with a shorter event-free survival (EFS). CEBPAbZIP-inf patients with a shorter EFS had higher expression of IFN-stimulated genes (IRF2, IRF5, OAS2, and IFI35). Genes in mitochondrial complexes I (NDUFA12 and NDUFB6) and V (ATP5PB and ATP5IF1) were overexpressed and were associated with poorer survival, and the results were independently validated in the TARGET AML cohort. In conclusion, concurrent WT1 or DNMT3A mutations and a dysregulated immune and metabolic state were correlated with poor survival in patients with CEBPAbZIP-inf, and upfront allogeneic transplantation may be indicated for better long-term disease control.

Validation of the molecular international prognostic scoring system in patients with myelodysplastic syndromes defined by international consensus classification.

Myelodysplastic syndromes (MDS) have varied prognoses and require a risk-adapted treatment strategy for treatment optimization. Recently, a molecular prognostic model (Molecular International Prognostic Scoring System [IPSS-M]) that combines clinical parameters, cytogenetic abnormalities, and mutation topography was proposed. This study validated the IPSS-M in 649 patients with primary MDS (based on the 2022 International Consensus Classification [ICC]) and compared its prognostic power to those of the IPSS and revised IPSS (IPSS-R). Overall, 42.5% of the patients were reclassified and 29.3% were up-staged from the IPSS-R. After the reclassification, 16.9% of the patients may receive different treatment strategies. The IPSS-M had greater discriminative potential than the IPSS-R and IPSS. Patients with high, or very high-risk IPSS-M might benefit from allogeneic hematopoietic stem cell transplantation. IPSS-M, age, ferritin level, and the 2022 ICC categorization predicted outcomes independently. After analyzing demographic and genetic features, complementary genetic analyses, including KMT2A-PTD, were suggested for accurate IPSS-M categorization of patients with ASXL1, TET2, STAG2, RUNX1, SF3B1, SRSF2, DNMT3A, U2AF1, and BCOR mutations and those classified as MDS, not otherwise specified with single lineage dysplasia/multi-lineage dysplasia based on the 2022 ICC. This study confirmed that the IPSS-M can better risk-stratified MDS patients for optimized therapeutic decision-making.

Validation of the prognostic significance of the 2022 European LeukemiaNet risk stratification system in intensive chemotherapy treated aged 18 to 65 years patients with de novo acute myeloid leukemia.

The European LeukemiaNet (ELN) recently proposed a revised recommendation for the diagnosis and management of acute myeloid leukemia (AML) in adults, recognized as ELN-2022. However, validation in a large real-world cohort remains lacking. In this study, we aimed to validate the prognostic relevance of the ELN-2022 in a cohort of 809 de novo, non-M3, younger (ages 18-65 years) AML patients receiving standard chemotherapy. The risk categories of 106 (13.1%) patients were reclassified from that determined using ELN-2017 to that determined using ELN-2022. The ELN-2022 effectively helped distinguish patients as favorable, intermediate, and adverse risk groups in terms of remission rates and survival. Among patients who achieved first complete remission (CR1), allogeneic transplantation was beneficial for those in the intermediate risk group, but not for those in the favorable or adverse risk groups. We further refined the ELN-2022 system by re-categorizing AML patients with t(8;21)(q22;q22.1)/RUNX1::RUNX1T1 with KIThigh , JAK2 or FLT3-ITDhigh mutations into the intermediate risk subset, AML patients with t(7;11)(p15;p15)/NUP98::HOXA9 and AML patients with co-mutated DNMT3A and FLT3-ITD into the adverse risk subsets, and AML patients with complex or monosomal karyotypes, inv (3)(q21.3q26.2) or t(3;3)(q21.3;q26.2)/GATA2,MECOM(EVI1) or TP53 mutation into the very adverse risk subset. The refined ELN-2022 system performed effectively to distinguish patients as favorable, intermediate, adverse, and very adverse risk groups. In conclusion, the ELN-2022 helped distinguish younger, intensively treated patients into three groups with distinct outcomes; the proposed refinement of ELN-2022 may further improve risk stratification among AML patients. Prospective validation of the new predictive model is necessary.

Poor prognostic implications of myelodysplasia-related mutations in both older and younger patients with de novo AML.

A set of myelodysplasia-related (MDS-R) gene mutations are incorporated into the 2022 European LeukemiaNet risk classification as adverse genetic factors for acute myeloid leukemia (AML) based on their poor prognostic impact on older patients. The impact of these mutations on younger patients (age < 60 years) remains elusive. In the study of 1213 patients with de novo non-M3 AML, we identified MDS-R mutations in 32.7% of the total cohort, 44.9% of older patients and 23.4% of younger patients. The patients with MDS-R mutations had a significantly lower complete remission rate in both younger and older age groups. With a median follow-up of 9.2 years, the MDS-R group experienced shorter overall survival (P = 0.034 for older and 0.035 for younger patients) and event-free survival (P = 0.004 for older and 0.042 for younger patients). Furthermore, patients with MDS-R mutations more frequently harbored measurable residual disease that was detectable using next generation sequencing at morphological CR than those without MDS-R mutations. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) might ameliorate the negative impact of MDS-R mutations. In summary, AML patients with MDS-R mutations have significantly poorer outcomes regardless of age. More intensive treatment, such as allo-HSCT and/or novel therapies, is warranted for AML patients with MDS-R mutations.

Clinico-genetic and prognostic analyses of 716 patients with primary myelodysplastic syndrome and myelodysplastic syndrome/acute myeloid leukemia based on the 2022 International Consensus Classification.

The 2022 International Consensus Classification (ICC) recategorized myeloid neoplasms based on recent advances in the understanding of the biology of hematologic malignancies, in which myelodysplastic syndrome (MDS) with blasts of 10%-19% is classified as MDS/acute myeloid leukemia (AML), MDS with mutated SF3B1, irrespective of the number of ring sideroblasts, as MDS-SF3B1, and those with multi-hit TP53 mutations as MDS with mutated TP53. In the analysis of 716 patients with MDS diagnosed according to the 2016 WHO classification, we found that 75.3% of patients remained in the MDS group based on the ICC, while 24.7% of patients were reclassified to the MDS/AML group after the exclusion of 15 patients who were classified to the AML group. Patients with MDS/AML showed a distinct mutational landscape and had poorer outcomes, compared to those with MDS. In the MDS group, patients with MDS-SF3B1 had higher frequencies of DNMT3A and TET2 mutations than those with MDS, not otherwise specified, with single lineage dysplasia or multilineage dysplasia. Patients with mutated TP53 were associated with dismal outcomes, irrespective of the blast percentage. In conclusion, this study showed that the ICC facilitates efficient segregation and risk-stratification of MDS which can help guide the treatment choice of patients with the disease.

Distinct genetic landscapes and their clinical implications in younger and older patients with myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are a group of clinically and genetically diverse diseases that impose patients with an increased risk of leukemic transformation. While MDS is a disease of the elderly, the interplay between aging and molecular profiles is not fully understood, especially in the Asian population. Thus, we compared the genetic landscape between younger and older patients in a cohort of 698 patients with primary MDS to advance our understanding of the distinct pathogenesis and different survival impacts of gene mutations in MDS according to age. We found that the average mutation number was higher in the older patients than younger ones. The younger patients had more WT1 and CBL mutations, but less mutated ASXL1, DNMT3A, TET2, SF3B1, SRSF2, STAG2, and TP53 than the older patients. In multivariable survival analysis, RUNX1 mutations with higher variant allele frequency (VAF) and U2AF1 and TP53 mutations were independent poor prognostic indicators in the younger patients, whereas DNMT3A and IDH2 mutations with higher VAF and TP53 mutations conferred inferior outcomes in the older patients. In conclusion, we demonstrated the distinct genetic landscape between younger and older patients with MDS and suggested that mutations impact survival in an age-depended manner.

Effect of mutation allele frequency on the risk stratification of myelodysplastic syndrome patients.

Myelodysplastic syndrome (MDS) is a heterogeneous group of clonal myeloid malignancies. Though several recurrent mutations are closely correlated with clinical outcomes, data concerning the association between mutation variant allele frequencies (VAF) and prognosis are limited. In this study, we performed comprehensive VAF analyses of relevant myeloid-malignancy related mutations in 698 MDS patients and correlated the results with their prognosis. Mutation VAF in DNMT3A, TET2, ASXL1, EZH2, SETBP1, BCOR, SFSF2, ZRSR2, and TP53 mutations correlated with outcomes. In multivariable analysis, DNMT3A and ZRSR2 mutations with high VAF and mutant IDH2, CBL, U2AF1, and TP53 were independent poor prognostic factors for overall survival. A substantial portion of patients in each revised International Prognostic Scoring System (IPSS-R) risk group could be adjusted to different prognostic groups based on the integrated VAF and mutational profiles. Patients with these unfavorable mutations in each IPSS-R risk subgroup had survivals worse than other patients of the same risk but similar to those in the next higher-risk subgroup. Furthermore, patients harboring U2AF1 mutation might benefit from hypomethylating agents. This study demonstrated the critical role of VAF of mutations for risk stratification in MDS patients and may be incorporated in novel scoring systems.

Distinct clinico-biological features in AML patients with low allelic ratio FLT3-ITD: role of allogeneic stem cell transplantation in first remission.

The mutant burden of FLT3-ITD modulates its prognostic impact on patients with acute myeloid leukemia (AML). However, for patients with low allelic ratio (AR) FLT3-ITD (FLT3-ITDlow, AR < 0.5), clinical features, as well as genomic and transcriptomic profiles remain unclear, and evidence supporting allogeneic hematopoietic stem cell transplantation (allo-HSCT) in first complete remission (CR1) remains controversial. This study aimed to elucidate the genomic features, prognosis, and transplantation outcome of FLT3-ITDIow in AML patients with intermediate-risk cytogenetics. FLT3-ITDlow was associated with a negative enrichment of the leukemic stem cell signature, a marked enrichment of the RAS pathway, and with higher frequencies of RAS pathway mutations, different from those with FLT3-ITDhigh. Concurrent CEBPA double mutations were favorable prognostic factors, whereas MLL-PTD, and mutations in splicing factors were unfavorable prognostic factors in FLT3-ITDlow patients. Patients with FLT3-ITDlow had a shorter overall survival (OS) and event-free survival (EFS) than those with FLT3wt. Allo-HSCT in CR1 was associated with a significantly longer OS and EFS compared with postremission chemotherapy in patients with FLT3-ITDlow. In conclusion, FLT3-ITDlow is associated with different mutational and transcriptomic profiles compared with FLT3-ITDhigh. The presence of concomitant poor-risk mutations exert negative prognostic impacts in patients with FLT3-ITDlow, who markedly benefit from allo-HSCT in CR1.

A CIBERSORTx-based immune cell scoring system could independently predict the prognosis of patients with myelodysplastic syndromes.

Aside from cell intrinsic factors such as genetic alterations, immune dysregulation in the bone marrow (BM) microenvironment plays a role in the development and progression of myelodysplastic syndromes (MDS). However, the prognostic implications of various immune cells in patients with MDS remain unclear. We adopted CIBERSORTx to estimate the relative fractions of 22 subtypes of immune cells in the BM of 316 patients with MDS and correlated the results with clinical outcomes. A lower fraction of unpolarized M0 macrophages and higher fractions of M2 macrophages and eosinophils were significantly associated with inferior survival. An immune cell scoring system (ICSS) was constructed based on the proportion of these 3 immune cells in the BM. The ICSS high-risk patients had higher BM blast counts, higher frequencies of poor-risk cytogenetics, and more NPM1, TP53, and WT1 mutations than intermediate- and low-risk patients. The ICSS could stratify patients with MDS into 3 risk groups with distinct leukemia-free survival and overall survival among the total cohort and in the subgroups of patients with lower and higher disease risk based on the revised International Prognostic Scoring System (IPSS-R). The prognostic significance of ICSS was also validated in another independent cohort. Multivariable analysis revealed that ICSS independently predicted prognosis, regardless of age, IPSS-R, and mutation status. Bioinformatic analysis demonstrated a significant correlation between high-risk ICSS and nuclear factor κB signaling, oxidative stress, and leukemic stem cell signature pathways. Further studies investigating the mechanistic insight into the crosstalk between stem cells and immune cells are warranted.

Clinical implications of sequential MRD monitoring by NGS at 2 time points after chemotherapy in patients with AML.

Next-generation sequencing (NGS) has been applied to measurable/minimal residual disease (MRD) monitoring after induction chemotherapy in patients with acute myeloid leukemia (AML), but the optimal time point for the test remains unclear. In this study, we aimed to investigate the clinical significance of NGS MRD at 2 different time points. We performed targeted NGS of 54 genes in bone marrow cells serially obtained at diagnosis, first complete remission (first time point), and after the first consolidation chemotherapy (second time point) from 335 de novo AML patients. Excluding DNMT3A, TET2, and ASXL1 mutations, which are commonly present in individuals with clonal hematopoiesis of indeterminate potential, MRD could be detected in 46.4% of patients at the first time point (MRD1st), and 28.9% at the second time point (MRD2nd). The patients with detectable NGS MRD at either time point had a significantly higher cumulative incidence of relapse and shorter relapse-free survival and overall survival. In multivariate analysis, MRD1st and MRD2nd were both independent poor prognostic factors. However, the patients with positive MRD1st but negative MRD2nd had a similar good prognosis as those with negative MRD at both time points. The incorporation of multiparameter flow cytometry and NGS MRD revealed that the presence of NGS MRD predicted poorer prognosis among the patients without detectable MRD by multiparameter flow cytometry at the second time point but not the first time point. In conclusion, the presence of NGS MRD, especially after the first consolidation therapy, can help predict the clinical outcome of AML patients.

Long non-coding RNA HOXB-AS3 promotes myeloid cell proliferation and its higher expression is an adverse prognostic marker in patients with acute myeloid leukemia and myelodysplastic syndrome.

BACKGROUND: Long non-coding RNAs (lncRNAs) represent the majority of cellular transcripts and play pivotal roles in hematopoiesis. However, their clinical relevance in acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) remains largely unknown. Here, we investigated the functions of HOXB-AS3, a lncRNA located at human HOXB cluster, in the myeloid cells, and analyzed the prognostic significances in patients with AML and MDS. METHODS: shRNAs were used to downregulate HOXB-AS3 in the cell lines and the effect was evaluated by quantitative polymerase chain reaction. The proliferation of the cell lines was illustrated by proliferation and BrdU flow assays. Further, we retrospectively analyzed the HOXB-AS3 expression in 193 patients with AML and 157 with MDS by microarray analysis, and evaluated its clinical importance. RESULTS: Downregulation of HOXB-AS3 suppressed cell proliferation. Mechanistically, HOXB-AS3 potentiated the expressions of several key factors in cell cycle progression and DNA replication without affecting the expressions of HOX genes. In AML, patients with higher HOXB-AS3 expression had shorter survival than those with lower HOXB-AS3 expression (median overall survival (OS), 17.7 months versus not reached, P <  0.0001; median relapse-free survival, 12.9 months versus not reached, P = 0.0070). In MDS, patients with higher HOXB-AS3 expression also had adverse prognosis compared with those with lower HOXB-AS3 expression (median OS, 14.6 months versus 42.4 months, P = 0.0018). The prognostic significance of HOXB-AS3 expression was validated in the TCGA AML cohort and another MDS cohort from our institute. The subgroup analyses in MDS patients showed that higher HOXB-AS3 expressions could predict poor prognosis only in lower-risk (median OS, 29.2 months versus 77.3 months, P = 0.0194), but not higher-risk group. CONCLUSIONS: This study uncovers a promoting role of HOXB-AS3 in myeloid malignancies and identifies the prognostic value of HOXB-AS3 expression in AML and MDS patients, particularly in the lower-risk group.

Incorporation of long non-coding RNA expression profile in the 2017 ELN risk classification can improve prognostic prediction of acute myeloid leukemia patients.

BACKGROUND: Expression of long non-coding RNAs (lncRNAs) has recently been recognized as a potential prognostic marker in acute myeloid leukemia (AML). However, it remains unclear whether incorporation of the lncRNAs expression in the 2017 European LeukemiaNet (ELN) risk classification can further improve the prognostic prediction. METHODS: We enrolled 275 newly diagnosed non-M3 AML patients and randomly assigned them to the training (n = 183) and validation cohorts (n = 92). In the training cohort, we formulated a prognostic lncRNA scoring system composed of five lncRNAs with significant prognostic impact from the lncRNA expression profiling. FINDINGS: Higher lncRNA scores were significantly associated with older age and adverse gene mutations. Further, the higher-score patients had shorter overall and disease-free survival than lower-score patients, which were also confirmed in both internal and external validation cohorts (TCGA database). The multivariate analyses revealed the lncRNA score was an independent prognosticator in AML, irrespective of the risk based on the 2017 ELN classification. Moreover, in the 2017 ELN intermediate-risk subgroup, lncRNA scoring system could well dichotomize the patients into two groups with distinct prognosis. Within the ELN intermediate-risk subgroup, we found that allogeneic hematopoietic stem cell transplantation could provide better outcome on patients with higher lncRNA scores. Through bioinformatics approach, we identified high lncRNA scores were correlated with leukemia/hematopoietic stem cell signatures. INTERPRETATION: Incorporation of lncRNA scoring system in 2017 ELN classification can improve risk-stratification of AML patients and help clinical decision-making. FUND: This work was supported Ministry of Science and Technology, and Ministry of Health and Welfare of Taiwan.

GATA2 zinc finger 1 mutations are associated with distinct clinico-biological features and outcomes different from GATA2 zinc finger 2 mutations in adult acute myeloid leukemia.

Mutations of the GATA binding protein 2 (GATA2) gene in myeloid malignancies usually cluster in the zinc finger 1 (ZF1) and the ZF2 domains. Mutations in different locations of GATA2 may have distinct impact on clinico-biological features and outcomes in AML patients, but little is known in this aspect. In this study, we explored GATA2 mutations in 693 de novo non-M3 AML patients and identified 44 GATA2 mutations in 43 (6.2%) patients, including 31 in ZF1, 10 in ZF2, and three outside the two domains. Different from GATA2 ZF2 mutations, ZF1 mutations were closely associated with French-American-British (FAB) M1 subtype, CEBPA double mutations (CEBPAdouble-mut), but inversely correlated with FAB M4 subtype, NPM1 mutations, and FLT3-ITD. ZF1-mutated AML patients had a significantly longer overall survival (OS) than GATA2-wild patients and ZF2-mutated patients in total cohort as well as in those with intermediate-risk cytogenetics and normal karyotype. ZF1 mutations also predicted better disease-free survival and a trend of better OS in CEBPAdouble-mut patients. Sequential analysis showed GATA2 mutations could be acquired at relapse. In conclusion, GATA2 ZF1 mutations are associated with distinct clinico-biological features and predict better prognosis, different from ZF2 mutations, in AML patients.

The prognostic significance of global aberrant alternative splicing in patients with myelodysplastic syndrome.

Aberrant alternative splicing (AS) is a hallmark of cancer development. However, there are limited data regarding its clinical implications in myelodysplastic syndrome (MDS). In this study, we performed an in-depth analysis of global AS in 176 primary MDS patients with 20 normal marrow transplant donors as reference. We found that 26.9% of the expressed genes genome-wide were aberrantly spliced in MDS patients compared with normal donors. These aberrant AS genes were related to pathways involved in cell proliferation, cell adhesion and protein degradation. A higher degree of global aberrant AS was associated with male gender and U2AF1 mutation, and predicted shorter overall survival and time to leukemic change. Moreover, it was an independent unfavorable prognostic factor irrespective of age, revised international prognostic scoring system (IPSS-R) risk, and mutations in SRSF2, ZRSR2, ASXL1, TP53, and EZH2. With LASSO-Cox regression method, we constructed a simple prognosis prediction model composed of 13 aberrant AS genes, and demonstrated that it could well stratify MDS patients into distinct risk groups. To our knowledge, this is the first report demonstrating significant prognostic impacts of aberrant splicing on MDS patients. Further prospective studies in larger cohorts are needed to confirm our observations.

Incorporation of mutations in five genes in the revised International Prognostic Scoring System can improve risk stratification in the patients with myelodysplastic syndrome.

Gene mutations have not yet been included in the 2016 WHO classification and revised International Prognostic Scoring System (IPSS-R), which are now widely utilized to discriminate myelodysplastic syndrome (MDS) patients regarding risk of leukemia evolution and overall survival (OS). In this study, we aimed to investigate whether integration of gene mutations with other risk factors could further improve the stratification of MDS patients. Mutational analyses of 25 genes relevant to myeloid malignancies in 426 primary MDS patients showed that mutations of CBL, IDH2, ASXL1, DNMT3A, and TP53 were independently associated with shorter survival. Patients within each IPSS-R or 2016 WHO classification-defined risk group could be stratified into two risk subgroups based on the mutational status of these five genes; patients with these poor-risk mutations had an OS shorter than others in the same risk group, but similar to those with the next higher risk category. A scoring system incorporating age, IPSS-R and five poor-risk mutations could divide the MDS patients into four risk groups (P < 0.001 for both OS and leukemia-free survival). In conclusion, integration of gene mutations in current IPSS-R improves the prognostication of MDS patients and may help identify high-risk patients for more aggressive treatment in IPSS-R lower risk group.

Dynamics of DNMT3A mutation and prognostic relevance in patients with primary myelodysplastic syndrome.

Background: DNMT3A gene mutation has been associated with poor prognosis in acute myeloid leukemia, but its clinical implications in myelodysplastic syndrome (MDS) and dynamic changes during disease progression remain controversial. Results: In this study, DNMT3A mutation was identified in 7.9% of 469 de novo MDS patients. DNMT3A-mutated patients had higher platelet counts at diagnosis, and patients with ring sideroblasts had the highest incidence of DNMT3A mutations, whereas those with multilineage dysplasia had the lowest incidence. Thirty-one (83.8%) of 37 DNMT3A-mutated patients had additional molecular abnormalities at diagnosis, and DNMT3A mutation was highly associated with mutations of IDH2 and SF3B1. Patients with DNMT3A mutations had a higher risk of leukemia transformation and shorter overall survival. Further, DNMT3A mutation was an independent poor prognostic factor irrespective of age, IPSS-R, and genetic alterations. The sequential study demonstrated that the original DNMT3A mutations were retained during follow-ups unless allogeneic hematopoietic stem cell transplantation was performed, while DNMT3A mutation was rarely acquired during disease progression. Conclusions: DNMT3A mutation predicts unfavorable outcomes in MDS and was stable during disease evolutions. It may thus be a potential biomarker to predict prognosis and monitor the treatment response.

Hyperleukocytosis is associated with distinct genetic alterations and is an independent poor-risk factor in de novo acute myeloid leukemia patients.

OBJECTIVES: Acute myeloid leukemia (AML) with hyperleukocytosis (HL) is intuitively thought as a unique group with dismal prognosis. However, comprehensive studies regarding the genetic landscape and clinical outcome in this group of patients are limited. METHODS: A total of 693 newly diagnosed de novo non-M3 AML patients were consecutively enrolled. We compared relevant mutations in 20 genes between AML patients with or without HL and exposed their prognostic implications. RESULTS: Hyperleukocytosis, defined as initial white blood cell counts above 50 000/µL, occurred in 28.9% of AML patients. HL patients had higher incidences of FLT3-ITD, NPM1, DNMT3A, CEBPA, and TET2 mutations. Multivariate analysis demonstrated that HL was an independent poor prognostic factor for overall survival and disease-free survival in total patients, those with intermediate-risk cytogenetics and normal karyotype irrespective of genetic alterations. Intriguingly, HL predicted poor survival in CEBPA double mutated, NPM1 + /FLT3-ITD- and NPM1-/FLT3-ITD- patients. Further, HL patients who received allogeneic hematopoietic stem cell transplantation (allo-HSCT) in first complete remission (CR) had a significantly longer overall survival and disease-free survival than those without allo-HSCT. CONCLUSIONS: Hyperleukocytosis is an independent poor prognostic factor irrespective of cytogenetics and mutation status. Allo-HSCT in first CR seems to ameliorate the poor prognostic impact of HL.