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.

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.

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.

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.

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.

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.

Higher HOPX expression is associated with distinct clinical and biological features and predicts poor prognosis in de novo acute myeloid leukemia.

Homeodomain-only protein homeobox (HOPX) is the smallest homeodomain protein. It was regarded as a stem cell marker in several non-hematopoietic systems. While the prototypic homeobox genes such as the HOX family have been well characterized in acute myeloid leukemia (AML), the clinical and biological implications of HOPX in the disease remain unknown. Thus we analyzed HOPX and global gene expression patterns in 347 newly diagnosed de novo AML patients in our institute. We found that higher HOPX expression was closely associated with older age, higher platelet counts, lower white blood cell counts, lower lactate dehydrogenase levels, and mutations in RUNX1, IDH2, ASXL1, and DNMT3A, but negatively associated with acute promyelocytic leukemia, favorable karyotypes, CEBPA double mutations and NPM1 mutation. Patients with higher HOPX expression had a lower complete remission rate and shorter survival. The finding was validated in two independent cohorts. Multivariate analysis revealed that higher HOPX expression was an independent unfavorable prognostic factor irrespective of other known prognostic parameters and gene signatures derived from multiple cohorts. Gene set enrichment analysis showed higher HOPX expression was associated with both hematopoietic and leukemia stem cell signatures. While HOPX and HOX family genes showed concordant expression patterns in normal hematopoietic stem/progenitor cells, their expression patterns and associated clinical and biological features were distinctive in AML settings, demonstrating HOPX to be a unique homeobox gene. Therefore, HOPX is a distinctive homeobox gene with characteristic clinical and biological implications and its expression is a powerful predictor of prognosis in AML patients.

GATA2 mutations in patients with acute myeloid leukemia-paired samples analyses show that the mutation is unstable during disease evolution.

Recently, mutations of the GATA binding protein 2 (GATA2) gene were identified in acute myeloid leukemia (AML) patients with CEBPA double mutations (CEBPA (double-mut)), but the interaction of this mutation with other genetic alterations and its dynamic changes during disease progression remain to be determined. In this study, 14 different missense GATA2 mutations, which were all clustered in the highly conserved N-terminal zinc finger 1 domain, were identified in 27.4, 6.7, and 1 % of patients with CEBPA (double-mut), CEBPA (single-mut), and CEBPA wild type, respectively. All but one patient with GATA2 mutation had concurrent CEBPA mutation. GATA2 mutations were closely associated with younger age, FAB M1 subtype, intermediate-risk cytogenetics, expression of HLA-DR, CD7, CD15, or CD34 on leukemic cells, and CEBPA mutation, but negatively associated with FAB M4 subtype, favorable-risk cytogenetics, and NPM1 mutation. Patients with GATA2 mutation had significantly better overall survival and relapse-free survival than those without GATA2 mutation. Sequential analysis showed that the original GATA2 mutations might be lost during disease progression in GATA2-mutated patients, while novel GATA2 mutations might be acquired at relapse in GATA2-wild patients. In conclusion, AML patients with GATA2 mutations had distinct clinic-biological features and a favorable prognosis. GATA2 mutations might be lost or acquired at disease progression, implying that it was a second hit in the leukemogenesis of AML, especially those with CEBPA mutation.

The clinical implication of SRSF2 mutation in patients with myelodysplastic syndrome and its stability during disease evolution.

Recurrent somatic mutation of SRSF2, one of the RNA splicing machinery genes, has been identified in a substantial proportion of patients with myelodysplastic syndrome (MDS). However, the clinical and biologic characteristics of MDS with this mutation remain to be addressed. In this study, 34 (14.6%) of the 233 MDS patients were found to have SRSF2 mutation. SRSF2 mutation was closely associated with male sex (P = .001) and older age (P < .001). It occurred concurrently with at least 1 additional mutation in 29 patients (85.3%) and was closely associated with RUNX1, IDH2, and ASXL1 mutations (P = .004, P < .001, and P < .001, respectively). Patients with SRSF2 mutation had an inferior overall survival (P = .010), especially in the lower risk patients. Further exploration showed that the prognostic impact of SRSF2 mutation might be attributed to its close association with old age. Sequential analyses in 173 samples from 66 patients showed that all SRSF2-mutated patients retained their original mutations, whereas none of the SRSF2-wild patients acquired a novel mutation during disease evolution. In conclusion, SRSF2 mutation is associated with distinct clinical and biologic features in MDS patients. It is stable during the clinical course and may play little role in disease progression.

DNMT3A mutations in acute myeloid leukemia: stability during disease evolution and clinical implications.

DNMT3A mutations are associated with poor prognosis in acute myeloid leukemia (AML), but the stability of this mutation during the clinical course remains unclear. In the present study of 500 patients with de novo AML, DNMT3A mutations were identified in 14% of total patients and in 22.9% of AML patients with normal karyotype. DNMT3A mutations were positively associated with older age, higher WBC and platelet counts, intermediate-risk and normal cytogenetics, FLT3 internal tandem duplication, and NPM1, PTPN11, and IDH2 mutations, but were negatively associated with CEBPA mutations. Multivariate analysis demonstrated that the DNMT3A mutation was an independent poor prognostic factor for overall survival and relapse-free survival in total patients and also in normokaryotype group. A scoring system incorporating the DNMT3A mutation and 8 other prognostic factors, including age, WBC count, cytogenetics, and gene mutations, into survival analysis was very useful in stratifying AML patients into different prognostic groups (P < .001). Sequential study of 138 patients during the clinical course showed that DNMT3A mutations were stable during AML evolution. In conclusion, DNMT3A mutations are associated with distinct clinical and biologic features and poor prognosis in de novo AML patients. Furthermore, the DNMT3A mutation may be a potential biomarker for monitoring of minimal residual disease.

The N-terminal CEBPA mutant in acute myeloid leukemia impairs CXCR4 expression.

CXC chemokine receptor 4 (CXCR4) is an essential regulator for homing and maintenance of hematopoietic stem cells within the bone marrow niches. Analysis of clinical implications of bone marrow CXCR4 expression in patients with acute myeloid leukemia showed not only higher CXCR4 expression was an independent poor prognostic factor, irrespective of age, white blood cell counts, cytogenetics, and mutation status of NPM1/FLT3-ITD and CEBPA, but also showed CXCR4 expression was inversely associated with mutations of CEBPA, a gene encoding transcription factor C/EBPα. Patients with wild-type CEBPA had significantly higher CXCR4 expression than those with mutated CEBPA. We hypothesized that CEBPA might influence the expression of CXCR4. To test this hypothesis, we first examined endogenous CXCR4 expression in 293T and K562 cells over-expressing wild-type C/EBPα p42 and demonstrated that CXCR4 levels were increased in these cells, whilst the expression of the N-terminal mutant, C/EBPα p30, diminished CXCR4 transcription. We further showed p42 was bound to the CXCR4 promoter by the chromatin immunoprecipitation assays. Induction of p42 in the inducible K562-C/EBPα cell lines increased the chemotactic migration. Moreover, decreased expression of C/EBPα by RNA interference decreased levels of CXCR4 protein expression in U937 cells, thereby abrogating CXCR4-mediated chemotaxis. Our results provide, for the first time, evidence that C/EBPα indeed regulates the activation of CXCR4, which is critical for the homing and engraftment of acute myeloid leukemia cells, while p30 mutant impairs CXCR4 expression.

SF3B1 mutations in patients with myelodysplastic syndromes: the mutation is stable during disease evolution.

The SF3B1 mutation can be detected in patients with myelodysplastic syndrome (MDS), but the report regarding the association of this mutation with other genetic alterations and its stability during disease progression is limited. In this study, SF3B1 mutations were identified in 10% of total cohort of 479 MDS patients and 61.8% of 34 patients with refractory anemia with ring sideroblasts (RARS). SF3B1 mutations were closely associated with older age, higher platelet counts, lower lactate dehydrogenase levels, good-risk cytogenetics, and mutations of DNMT3A, but inversely related to ASXL1 mutations. Most SF3B1-mutated patients had concurrent other genetic alterations, including DNMT3A and RUNX1 mutations. There was no prognostic difference between patients with SF3B1 mutations and those without. Sequential studies in 417 samples from 142 patients demonstrated that all SF3B1-mutated patients retained the same mutations during disease evolution with the exception of two patients who lost the mutation after allogeneic hematopoietic stem cell transplantation, whereas none of the SF3B1-wild patients acquired a novel mutation during clinical follow-ups. In conclusion, the patients with SF3B1 mutations had distinct clinic-biologic features. SF3B1 mutations, accompanied with other genetic alterations, especially DNMT3A mutations, may play a role in the development of MDS, but have little role in disease progression.

IDH mutations are closely associated with mutations of DNMT3A, ASXL1 and SRSF2 in patients with myelodysplastic syndromes and are stable during disease evolution.

Current information about clinical significance of IDH mutations in myelodysplastic syndromes (MDS), their association with other genetic alterations and the stability during disease progression is limited. In this study, IDH mutations were identified in 4.6% of 477 patients with MDS based on the FAB classification and in 2.2 % of 368 patients based on the 2008 WHO classification. IDH mutations were closely associated with older age, higher platelet counts, and mutations of DNMT3A (36.4% vs. 8.7%, P < 0.001), ASXL1 (47.6% vs. 22.0%, P = 0.007), and SRSF2 (45.5% vs. 11.8%, P < 0.001). IDH2 mutation was a poor prognostic factor for overall survival in patients with lower-risk MDS, based on international prognosis scoring system (IPSS), FAB classification, WHO classification, or revised IPSS (all P ≦ 0.001), but not in higher-risk groups. Sequential studies in 151 patients demonstrated that all IDH-mutated patients retained the same mutation during disease evolution while none of the IDH-wild patients acquired a novel mutation during follow-ups. In conclusion, IDH mutation is a useful biomarker for risk stratification of patients with lower-risk MDS. IDH mutations are stable during the clinical course. The mutation, in association with other genetic alterations, may play a role in the development, but not progression of MDS.

Clinical implications of the SETBP1 mutation in patients with primary myelodysplastic syndrome and its stability during disease progression.

Mutations of the SET binding protein 1 (SETBP1) gene have been identified in patients with myeloid neoplasms, but the clinical relevance of this mutation and its association with other gene mutations in myelodysplastic syndrome (MDS) and the stability during disease progression remains unclear. Mutations in SETBP1 gene at exon 4 were analyzed by polymerase chain reaction and direct sequencing in 430 MDS patients. The results were correlated with clinical features, cytogenetics, gene mutations and treatment outcomes. SETBP1 mutations were identified in 14 (3.3%) of the 430 patients with primary MDS based on the FAB classification and 8 (2.4%) of the 333 patients based on the WHO classification. The SETBP1 mutation was closely associated with higher white blood cell counts, isochromosome of 17q, monosomy 7, and mutations of ASXL1, EZH2 and SRSF2. With a median follow-up of 43.9 months, MDS patients, based on either the FAB or WHO classification, had a significantly poorer overall survival (OS) if they harbored SETBP1 mutation. Further, SETBP1 mutation was an independent poor prognostic factor for OS (HR = 1.842, CI 95%, 1.1018-3.332, P = 0.043) irrespective of age, sex, and the International Prognostic Scoring System. Sequential analysis showed that the original SETBP1 mutations in the eight SETBP1-mutated patients studied were retained while two of the 101 SETBP1-wild patients acquired novel SETBP1 mutations during follow-ups. The SETBP1 mutation is associated with poor prognosis in MDS. The mutation can be acquired during the clinical course suggesting it may play a role in disease progression.

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.

TET2 mutation is an unfavorable prognostic factor in acute myeloid leukemia patients with intermediate-risk cytogenetics.

The studies concerning clinical implications of TET2 mutation in patients with primary acute myeloid leukemia (AML) are scarce. We analyzed TET2 mutation in 486 adult patients with primary AML. TET2 mutation occurred in 13.2% of our patients and was closely associated with older age, higher white blood cell and blast counts, lower platelet numbers, normal karyotype, intermediate-risk cytogenetics, isolated trisomy 8, NPM1 mutation, and ASXL1 mutation but mutually exclusive with IDH mutation. TET2 mutation is an unfavorable prognostic factor in patients with intermediate-risk cytogenetics, and its negative impact was further enhanced when the mutation was combined with FLT3-ITD, NPM1-wild, or unfavorable genotypes (other than NPM1(+)/FLT3-ITD(-) or CEBPA(+)). A scoring system integrating TET2 mutation with FLT3-ITD, NPM1, and CEBPA mutations could well separate AML patients with intermediate-risk cytogenetics into 4 groups with different prognoses (P < .0001). Sequential analysis revealed that TET2 mutation detected at diagnosis was frequently lost at relapse; rarely, the mutation was acquired at relapse in those without TET2 mutation at diagnosis. In conclusion, TET2 mutation is associated with poor prognosis in AML patients with intermediate-risk cytogenetics, especially when it is combined with other adverse molecular markers. TET2 mutation appeared to be unstable during disease evolution.

Clinical implications of U2AF1 mutation in patients with myelodysplastic syndrome and its stability during disease progression.

We aimed to analyze clinical impacts of the U2AF1 mutation on patients with myelodysplastic syndrome (MDS) and its stability during disease progression. We checked mutation status of the U2AF1 by direct sequencing in 478 de novo MDS patients and correlated with the clinical characteristics and outcomes. We also sequentially analyzed the U2AF1 mutation in 421 samples from 142 patients to determine its stability during the disease courses. Thirty-six patients (7.5%) were found to have U2AF1 mutations, which occurred more frequently in younger patients (P = 0.033). U2AF1 mutation was an independent poor-risk factor for overall survival (OS) in all patients (P = 0.030) and younger patients (P = 0.041). U2AF1 mutation could also predict shorter time-to-leukemia transformation (TTL) in younger patients (P = 0.020). In addition, U2AF1 mutation was associated with shorter TTL in lower-risk MDS patients. Sequential analyses showed all original U2AF1 mutations in U2AF1-mutated patients were retained during follow-ups unless complete remission was achieved, whereas none of the U2AF1-wild patients acquired a novel mutation during disease evolution. U2AF1 mutation is more prevalent in younger MDS patients and associated with inferior outcomes although it is stable during the clinical course. The mutation may be used as a biomarker for risk stratification.

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.