Classification Of Myelodysplastic Syndromes Research Articles

The E592K variant of SF3B1 creates unique RNA missplicing and associates with high-risk MDS without ring sideroblasts

AbstractAmong the most common genetic alterations in the myelodysplastic syndromes (MDS) are mutations in the spliceosome gene SF3B1. Such mutations induce specific RNA missplicing events, directly promote ring sideroblast (RS) formation, and generally associate with a more favorable prognosis. However, not all SF3B1 mutations are the same, and little is known about how distinct hotspots influence disease. Here we report that the E592K variant of SF3B1 associates with high-risk disease features in MDS, including a lack of RS, increased myeloblasts, a distinct comutation pattern, and a lack of favorable survival seen with other SF3B1 mutations. Moreover, compared with other hot spot SF3B1 mutations, E592K induces a unique RNA missplicing pattern, retains an interaction with the splicing factor SUGP1, and preserves normal RNA splicing of the sideroblastic anemia genes TMEM14C and ABCB7. These data have implications for our understanding of the functional diversity of spliceosome mutations, as well as the pathobiology, classification, prognosis, and management of SF3B1-mutant MDS.

Two-Time Multiplexed Targeted Next-Generation Sequencing Might Help the Implementation of Germline Screening Tools for Myelodysplastic Syndromes/Hematologic Neoplasms.

Next-generation sequencing (NGS) tools have importantly helped the classification of myelodysplastic syndromes (MDS), guiding the management of patients. However, new concerns are under debate regarding their implementation in routine clinical practice for the identification of germline predisposition. Cost-effective targeted NGS tools would improve the current standardized studies and genetic counseling. Here, we present our experience in a preliminary study detecting variants using a two-time multiplexed library strategy. Samples from different MDS patients were first mixed before library preparation and later multiplexed for a sequencing run. Two different mixes including a pool of three (3×) and four (4×) samples were evaluated. The filtered variants found in the individually sequenced samples were compared with the variants found in the two-time multiplexed studies to determine the detection efficiency scores. The same candidate variants were found in the two-time multiplexed studies in comparison with the individual tNGS. The variant allele frequency (VAF) values of the candidate variants were also compared. No significant differences were found between the expected and observed VAF percentages in both the 3× (p-value 0.74) and 4× (p-value 0.34) multiplexed studies. Our preliminary results suggest that the two-time multiplexing strategy might have the potential to help reduce the cost of evaluating germline predisposition.

Somatic Mutations and DNA Hypermethylation at Enhancers and Promoters Identify Distinct Subtypes within Lower-Risk Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) are a group of heterogeneous disorders caused by the accumulation of somatic mutations in the hematopoietic stem and progenitor compartment. Besides del(5q), SF3B1 or TP53 mutations, referred to as defining genetic abnormalities, mutation patterning hardly structured the classification of MDS. Mutations in epigenetic factors occur early in the development of clonal hematopoiesis leading to precocious alterations of DNA methylation implicated in oncogenesis. Convergent DNA methylation patterns related to both mutations and microenvironment imprinting may induce specific gene expression profiles and contribute to phenotypic variations. To refine a pathophysiological classification of lower-risk MDS, we combined genetic profiling to DNA methylation and transcriptome data. Methods: We enrolled 543 lower-risk treatment-naïve MDS patients at diagnosis and performed DNA-sequencing of 24 genes. DNA methylation and RNA-sequencing data were generated in a representative subset of 175 cases with available material (75 MDS-SLD/MLD, 40 MDS-EB1, 53 MDS-RS-SLD/MLD, 5 MDS del(5q), 2 MDS-U) and 7 age-matched healthy controls. IPSS-R was very low, low or intermediate in 87.4%. During a median follow-up of 2 years, 16% of MDS cases progressed to AML (MDSp). Infinium EPIC 850K array allowed after filtering the examination of methylation of 723,612 CpG sites with enrichment at enhancers and promoters. Differentially methylated regions with differentially methylated CpG sites (DMR-CpG) between cases and controls were defined with a minimum of 2 probes, a Benjamini-Hochberg-adjusted P-value cut-off of 0.05, a false discovery rate of 0.001 and a mean Δβ-value >20% at CpG sites. Consensus motifs for transcription factors were identified using Homer. Results: Unsupervised clustering on genetic profiling of 543 patients identified distinct subsets of lower-risk MDS with different clinical features: one cluster (group A) was enriched in del(5q), three clusters were characterized by SF3B1 mutations, either isolated (group B) or associated with DNMT3A (group E) or TET2 (group F), while the two remaining clusters were enriched in either complex pattern of mutations (group C) or SRSF2 mutations (group D). Genetic clusters showed significantly different clinical outcomes, clusters C, D and E having lower overall survival and higher risk of progression to high risk MDS or AML compared to other clusters. In the subset of 175 cases, a total of 2,953 unique DMR-CpGs allowed a robust repartition of patient samples in 4 groups using the k-means method. The 4 methylation groups were clinically distinct in terms of age, hemoglobin, neutrophils, monocytes, platelets, BM blasts, WHO classification, IPSS-R, and mutation pattern. A significant correlation was found between genetic and methylation groups ( P<0.001). Hypomethylated CpGs defined group 4 which was enriched in MDS-RSwith low blast count and few co-mutations, while groups 1 and 3 demonstrated hypermethylated profiles driven by TET2/ IDH1-2 mutations and TET2/ SRSF2 mutations, respectively. TET2-mutated cases exhibited an increased proportion of hypermethylated DMR-CpGs at enhancers (DME) significantly enriched in C/EBP and ETS family transcription factor motifs. In MDS without evidence of progression, we identified 1,418 DME and their gene targets of which those significantly deregulated in RNA-seq were involved in the control of translation and response to TGF-β. By contrast, in MDS with rapid progression to AML, DMR-CpGs were significantly enriched at CpG islands and promoters ( P<0.0001) and a set of 10-20 genes downstream of these promoters were specifically deregulated. Conclusion: Somatic mutations and DNA methylation at enhancers and promoters identify distinct subsets of lower-risk MDS with different clinical behavior. Hypermethylation at enhancers with C/EBP or ETS family motifs is a hallmark of MDS and may account for changes in transcription factor recruitment and cell fate. Hypermethylation of promoters with downstream effects on gene expression may indicate a propensity to rapid evolution to AML.

Myelodysplastic Syndrome Associated Hemophagocytic Lymphohistiocytosis: A Retrospective Study of 15 Cases in a Single Center

Introduction: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disorder characterized by excessive cytokine secretion, resulting in hyperinflammation and multiorgan dysfunction. It is classified into primary HLH, which is mainly caused by genetic defects, and secondary HLH, triggered by various underlying conditions. Malignancy-associated HLH (M-HLH) is a secondary form commonly observed in patients with hematological malignancies, such as lymphomas, T/NK-cell disorders, acute leukemias, lymphoproliferative diseases, and myelodysplastic syndrome (MDS). M-HLH can occur in up to 1% of patients with hematologic malignancies, with lymphoma being the most frequently associated malignancy. HLH initiated by MDS is a rare entity with only a few cases reported, leading to limited knowledge regarding its pathogenesis, diagnosis and optimal treatment strategies. Methods: In this retrospective study, we analyzed a consecutive series of MDS-HLH patients admitted to our center between March 1, 2019, and March 1, 2023. Bio-clinical data related with MDS and HLH were collected at diagnosis of MDS-HLH. Additional observational indicators encompassed the following: basic clinical characteristics of the patients (age at onset, gender, duration of MDS prior to HLH), correlation between the onset of HLH and MDS, treatment and response, and genetic defects associated with HLH and MDS. MDS risk classification was according to the Revised International Prognosis Scoring System (IPSS-R) and the WHO classification-based Prognosis Scoring System, while patients were categorized into two groups as higher-risk and lower-risk MDS-HLH group. The follow-up period started at the time of MDS-HLH diagnosis and ended at the date of death or last examination. Overall survival (OS) was calculated from the time of HLH diagnosis to the date of death from any cause. Results: A total of 15 patients diagnosed with MDS-HLH were included in the study, with a median age of 66 years (range, 33-83 years). The majority of patients (10/15, 67%) were over 60 years old. All patients exhibited typical features of aggressive HLH: fever, cytopenia and elevated serum ferritin in all patients, hepatomegaly/splenomegaly in 87% (13/15), hypofibrinogenemia/hypertriglyceridemia in 73% (11/15), hemophagocytosis in 73% (11/15), low NK-cell activity in 21% (3/14), and elevated levels of sCD25 in 93% of patients (14/15). Additionally, four patients (27%) had concurrent Epstein-Barr virus (EBV) infection. Further analysis comparing the lower-risk and higher-risk MDS-HLH groups revealed interesting findings. In the lower-risk group, all patients developed HLH concurrently with the diagnosis of MDS. However, in the higher-risk group, the majority of patients (6/8, 62.5%) experienced HLH onset during MDS progression or relapse (p=0.014). Among the 15 patients, 8 patients (53.3%) achieved remission of HLH. During the study period, 8 deaths occurred, all directly attributed to HLH or its complications. The majority of deaths (75%, 6/8) occurred within the first two months after HLH diagnosis. The median overall survival was 12.3 weeks (95%CI, 1.1-23.5). Patients who achieved complete or partial response had significantly prolonged overall survival compared to those who did not respond to treatment (p=0.002). In the multivariate analysis of prognosis, the remission status of HLH was the only factor which was significantly associated with survival (p=0.018, Exp(B)=0.003). Conclusion: This is the first comprehensive study focusing specifically on MDS-HLH, providing valuable insights into the clinical characteristics, treatment outcomes, and prognosis of MDS-HLH. The findings emphasize the need of considering revision of diagnostic criteria specially for MDS-HLH. The pathogenesis of HLH in MDS-HLH differs based on the risk classification of MDS, with higher-risk cases driven by malignancy and lower-risk cases associated with immune dysfunction. The prognosis of MDS-HLH is generally poor. Achieving remission of HLH is crucial for improving the prognosis of MDS-HLH patients. Conventional chemotherapy regimens, including etoposide, have shown limited efficacy and safety in this context. Chemotherapy-free regimens should be preferred considering the features of ineffective hematopoiesis in MDS. The role of EBV infection in MDS-HLH development should be recognized.

Molecular Taxonomy of Myelodysplastic Syndromes and Its Clinical Implications

Background Recurrent genetic abnormalities are responsible for the pathogenesis of myelodysplastic syndromes (MDS) and their biologic heterogeneity, however current classifications of MDS are still largely based on morphology.Here, we propose a molecular taxonomy of MDS and describe its clinical relevance. Methods We assembled a cohort of 3,233 diagnostic MDS or related myeloid neoplasm samples from the International Working Group for the Prognosis of MDS. Gene mutations, copy-number alterations (CNAs) and copy-neutral loss of heterozygosity (cnLOH) events were derived from targeted sequencing of a 152-gene panel. Molecular features were used for unsupervised clustering analysis using Bayesian Dirichlet processes, and the results were manually curated into a rule-based hierarchical classification tree. Results We detected oncogenic mutations, CNAs, and cnLOH events in 91, 43, and 11% of patients, respectively. We validated and extended patterns of co-occurrence and mutual exclusivity between gene mutations and CNAs, and further described (i) specific occurrences in cis between gene mutations and cnLOH events, (ii) distinct patterns of co-mutation between the allelic state of a same locus (haploid LOH or cnLOH associated with -7/del(7q)), or of the same mutated gene ( TP53, TET2), and (iii) distinct patterns of co-mutation between hotspots of the same gene ( U2AF1). These patterns informed feature definition for clustering analysis. We characterized 18 distinct MDS molecular subgroups. The first 16 groups encompassed 86% (n=2,769) of patients and were based on the presence or absence of mutations in 21 genes ( ASXL1, BCOR, BCORL1, DDX41, DNMT3A, EZH2, FLT3, IDH1, IDH2, MLL, MYC, NPM1, SETBP1, SF3B1, SRSF2, STAG2, TET2, TP53, U2AF1, WT1, ZRSR2), and 6 cytogenetic events (inv(3), complex karyotype, der(1;7), -7, del(5q), -Y), as well as LOH at the TP53 and TET2 locus. The molecularly not-otherwise specified (mNOS) group(8%, n=254) corresponded to the presence of other cytogenetic abnormalities and/or mutations in 51 other recurrently mutated genes (>0.5%). The No-event category (6%, n=210) was characterized by the absence of any recurrent drivers in our assay. Groups ranged in size from 0.5% to 14% of patients and were associated with distinct clinical phenotypes ( Fig 1A) and outcomes ( Fig 1B). The median bone marrow blast percentage across groups ranged from 1.5 to 10%, the median overall survival (OS) from 0.9 to 8.2 years, and the 2-year rate of leukemic transformation from 0 to 40%. The representation of molecular groups within blast strata (<5%, 5-9%, 10-19% blast percentages) was highly heterogeneous: 7, 8, and 9 different groups accounted for more than 5% of patients within each blast stratum, respectively. The prognostic impact of blast counts on outcomes depended on the molecular subgroups. Among the 12 molecular groups with at least 10 patients with outcome data in all 3 blast strata, blast count was prognostically significant in 8 of those groups ( SF3B1, CCUS-like, del(5q), bi-TET2, mNOS, BCOR/L1, IDH-STAG2, TP53-complex) and was not significant in 4 groups ( EZH2-ASXL1, -7/SETBP1, DDX41, AML-like). The molecular groups validated established ( TP53-complex, del(5q), SF3B1) and well characterized entities ( DDX41, AML-like), added further evidence to support previously reported subsets ( bi-TET2, der(1;7), CCUS-like), and described novel genetic subsets (-7/ SETBP1, EZH2-ASXL1, IDH-STAG2, BCOR/L1, U2AF157, U2AF134, SRSF2, ZRSR2). Finally, the MDS molecular groups were used to investigate the genetic heterogeneity of secondary/therapy-related MDS (s/t-MDS) and of myelodysplastic/myeloproliferative neoplasms (MDS/MPN). There were 7 and 6 distinct groups that accounted for more that 5% of patients with s/t-MDS or MDS/MPN, respectively. Within each genetic subgroup, s/t-MDS and MDS/MPN had similar clinical and outcome profiles to primary MDS. Conclusions The genetic complexity of MDS can be organized into 18 molecular groups that reflect the underlying genetic basis of the disease. The prognostic influence of bone marrow blasts varied in the individual genetic subgroups, suggesting that the clinical impact of increased blasts depends on the genetic context. The molecular taxonomy derived in this study is clinically relevant and will inform future classification schemas.

Prognostic Value of Measurable Residual Disease in High-Risk Myelodysplastic Syndromes with Intensive Chemotherapy Treatment: Analysis of HOVON-SAKK Studies

Diagnosis of myelodysplastic syndromes (MDS) and accurate risk assessment to tailor treatment remains challenging. High-risk MDS (hrMDS) patients who are fit enough may benefit from intensive chemotherapy followed by post-remission consolidation. The HOVON-SAKK (HO) acute myeloid leukemia (AML) trials, designed to test novel drug combinations with an intensive treatment regimen, included hrMDS patients (RAEB and RAEB-T). Since these HO-trials have been executed with large patient cohorts for many years, they offer the unique possibility to study the outcome, risk classification, and relevance of measurable residual disease (MRD) in hrMDS. A pooled database is available from HOVON-SAKK of patients who were treated with intensive chemotherapy (studies containing MDS patients with IPSS ≥ 1.5 HO42A, HO81, HO92, HO102, and IPSS-R > 4.5 HO103, HO132). The database contained 3268 patients; 11% (364/3268) were hrMDS scored according to IPSS and IPPS-R. Three-year overall survival (OS) for hrMDS was 32% (standard error; SE 2%) compared to AML 46% (SE 1%). In total, 1074 AML and 75 hrMDS had reached complete remission (CR/CRi) and received a second induction cycle (C2). MRD after C2 based on multiparameter flow cytometry (Cloos et al., 2018, J. Vis.) with a cut-off of ≥0.1% for MRD positivity was assessed to evaluate the MRD status. We observed a trend of a higher MRD positivity rate for MDS compared to AML patients (MDS vs. AML: 32% (23/73) vs. 22% (232/1064), P = 0.055). Kaplan-Meier OS analysis showed a significant prognostic value of MRD in MDS, but not in the cumulative incidence of relapse (CIR) (log-rank test 0.011, Gray's test P = 0.124). Since the MDS classification has been changed, we re-classified MDS based on the ICC 2022 classification into AML, AML/MDS, and MDS. We reclassified 3035 patients at diagnosis, including 2605 AML, 258 MDS/AML, and 172 MDS. The three-year OS was 47% (SE 1%) for AML, 29% (SE 3%) for MDS/AML, and 33% (SE 4%) for MDS. After C2, 2215 patients had reached CR/CRi. A total of 1074 patients containing 984 AML, 57 AML/MDS, and 33 high-risk MDS patients with CR/CRi after C2, with a suitable bone marrow sample, were included in the MRD analysis. Most patients were treated according to HO132 (40-48%). As expected, MDS patients were older (median age, range; 60, 32-74), had lower bone marrow blast counts, and were predominantly of adverse risk. A trend of a higher proportion of MRD positivity after C2 was observed in the MDS group (33%; 11/33) as compared to AML (22%; 215/984) or MDS/AML (18%; 10/57). Three-year OS was 61% for AML (SE 1.6%), 42% (SE 6.6%), and 49% (8.7%) for AML/MDS and MDS, respectively (Figure 1A). Kaplan-Meier OS analysis and CIR showed a significant prognostic value of MRD for MDS (log-rank test P<0.001, Gray's test P = 0.015) and AML ( P<0.001; P<0.001) but not for MDS/AML patients ( P = 0.5, P = 0.342)(Figure 1B). Remarkably, the three-year OS of MRDpos in MDS was 18% (SE 12%) compared to MRDpos in AML 40% (SE 16%). The limitation of this study is the relatively small number of MDS patients according to the new ICC 2022 guidelines. In summary, MRD detection in the HOVON-SAKK trials shows the potential of MRD as a prognostic value in MDS patients treated on intensive induction regimens with a clinically validated and standardized assay.

The French-American-British classification of myelodysplastic syndromes.

The French-American-British classification of myelodysplastic syndromes.

Myelodysplastic syndromes: 2023 update on diagnosis, risk-stratification, and management.

The myelodysplastic syndromes (MDS) are a very heterogeneous group of myeloid disorders characterized by peripheral blood cytopenias and increased risk of transformation to acute myelogenous leukemia (AML). MDS occurs more frequently in older males and in individuals with prior exposure to cytotoxic therapy. Diagnosis of MDS is based on morphological evidence of dysplasia upon visual examination of a bone marrow aspirate and biopsy. Information obtained from additional studies such as karyotype, flow cytometry, and molecular genetics is usually complementary and may help refine diagnosis. A new WHO classification of MDS was proposed in 2022. Under this classification, MDS is now termed myelodysplastic neoplasms. Prognosis of patients with MDS can be calculated using a number of scoring systems. All these scoring systems include analysis of peripheral cytopenias, percentage of blasts in the bone marrow, and cytogenetic characteristics. The most commonly accepted system is the Revised International Prognostic Scoring System (IPSS-R). Recently, genomic data has been incorporated resulting in the new IPSS-M classification. Therapy is selected based on risk, transfusion needs, percent of bone marrow blasts, cytogenetic and mutational profiles, comorbidities, potential for allogeneic stem cell transplantation (alloSCT), and prior exposure to hypomethylating agents (HMA). Goals of therapy are different in lower risk patients than in higher risk and in those with HMA failure. In lower risk, the goal is to decrease transfusion needs and transformation to higher risk disease or AML, as well as to improve survival. In higher risk, the goal is to prolong survival. In 2020, two agents were approved in the US for patients with MDS: luspatercept and oral decitabine/cedazuridine. In addition, currently other available therapies include growth factors, lenalidomide, HMAs, intensive chemotherapy, and alloSCT. A number of phase 3 combinations studies have been completed or are ongoing at the time of this report. At the present time there are no approved interventions for patients with progressive or refractory disease particularly after HMA based therapy. In 2021, several reports indicated improved outcomes with alloSCT in MDS as well as early results from clinical trials using targeted intervention.

Artificial intelligence to empower diagnosis of myelodysplastic syndromes by multiparametric flow cytometry.

The diagnosis of myelodysplastic syndromes (MDS) might be challenging and relies on the convergence of cytological, cytogenetic, and molecular factors. Multiparametric flow cytometry (MFC) helps diagnose MDS, especially when other features do not contribute to the decision-making process, but its usefulness remains underestimated, mostly due to a lack of standardization of cytometers. We present here an innovative model integrating artificial intelligence (AI) with MFC to improve the diagnosis and the classification of MDS. We develop a machine learning model through an elasticnet algorithm directed on a cohort of 191 patients, only based on flow cytometry parameters selected by the Boruta algorithm, to build a simple but reliable prediction score with five parameters. Our AI-assisted MDS prediction score greatly improves the sensitivity of the Ogata score while keeping an excellent specificity validated on an external cohort of 89 patients with an Area Under the Curve of 0.935. This model allows the diagnosis of both high- and low-risk MDS with 91.8% sensitivity and 92.5% specificity. Interestingly, it highlights a progressive evolution of the score from clonal hematopoiesis of indeterminate potential (CHIP) to highrisk MDS, suggesting a linear evolution between these different stages. By significantly decreasing the overall misclassification of 52% for patients with MDS and of 31.3% for those without MDS (P=0.02), our AI-assisted prediction score outperforms the Ogata score and positions itself as a reliable tool to help diagnose MDS.

Understanding the Continuum between High-Risk Myelodysplastic Syndrome and Acute Myeloid Leukemia

Myelodysplastic syndrome (MDS) is a clonal hematopoietic neoplasm characterized by bone marrow dysplasia, failure of hematopoiesis and variable risk of progression to acute myeloid leukemia (AML). Recent large-scale studies have demonstrated that distinct molecular abnormalities detected at earlier stages of MDS alter disease biology and predict progression to AML. Consistently, various studies analyzing these diseases at the single-cell level have identified specific patterns of progression strongly associated with genomic alterations. These pre-clinical results have solidified the conclusion that high-risk MDS and AML arising from MDS or AML with MDS-related changes (AML-MRC) represent a continuum of the same disease. AML-MRC is distinguished from de novo AML by the presence of certain chromosomal abnormalities, such as deletion of 5q, 7/7q, 20q and complex karyotype and somatic mutations, which are also present in MDS and carry crucial prognostic implications. Recent changes in the classification and prognostication of MDS and AML by the International Consensus Classification (ICC) and the World Health Organization (WHO) reflect these advances. Finally, a better understanding of the biology of high-risk MDS and the mechanisms of disease progression have led to the introduction of novel therapeutic approaches, such as the addition of venetoclax to hypomethylating agents and, more recently, triplet therapies and agents targeting specific mutations, including FLT3 and IDH1/2. In this review, we analyze the pre-clinical data supporting that high-risk MDS and AML-MRC share the same genetic abnormalities and represent a continuum, describe the recent changes in the classification of these neoplasms and summarize the advances in the management of patients with these neoplasms.

Myelodysplastic syndromes, thy name is heterogeneity.

Classification of the heterogeneous spectrum of myelodysplastic syndromes (MDS) requires both morphologic and molecular analysis to effectively subgroup patients. The paper by Zhang et al demonstrated the positive impact of combining the International Consensus Consortium (ICC) morphologic approach with prior clinical (IPSS-R) and mutational (IPSS-M) categorization to provide useful clinical evaluation of MDS patients. Commentary on: Zhang et al. Impact of the International Consensus Classification of Myelodysplastic Syndromes. Br J Haematol 2022 (Online ahead of print). doi: 10.1111/bjh.18628.

Impact of the International Consensus Classification of myelodysplastic syndromes.

The impact of the 2022 International Consensus Classification (ICC) of myelodysplastic syndromes (MDS) needs study. We analysed data from 989 MDS subjects classified using the 2016 World Health Organization (WHO) criteria to determine the impact of the new proposal. Our analyses suggested the ICC criteria of MDS-SF3B1 identifies a more homogenous disease entity than the WHO 2016 criteria of myelodysplastic syndromes with ring sideroblasts (MDS-RS). MDS, not otherwise specified with single lineage dysplasia (MDS, NOS-SLD) patients had a better prognosis than MDS, NOS with multilineage dysplasia (MDS, NOS-MLD) patients. MDS with mutated TP53 and MDS/acute myeloid leukaemia with mutated TP53 patients had the briefest survivals. These data support the ICC of MDS, which allows more accurate diagnoses and risk stratification.

Risk stratifying MDS in the time of precision medicine.

Myelodysplastic syndromes (MDS) are myeloid neoplasms characterized by morphologic dysplasia, persistent cytopenia, and a variable risk of evolution to acute myeloid leukemia (AML). Risk stratification is crucial in a patient-centered approach to the treatment of MDS. Based on hematologic parameters and cytogenetic abnormalities, the Revised International Prognostic Scoring System is currently used for this purpose. In the past years, the use of massively parallel DNA sequencing has clarified the genetic basis of MDS and has enabled development of novel diagnostic and prognostic approaches. When conventional cytogenetics is combined with gene sequencing, more than 90% of patients are found to carry a somatic genetic lesion. In addition, a portion of patients has germline variants that predispose them to myeloid neoplasms. The recently developed International Consensus Classification of MDS includes new entities that are molecularly defined-namely, SF3B1-mutant and TP53-mutant MDS. The International Working Group for Prognosis in MDS has just developed the International Prognostic Scoring System-Molecular (IPSS-M) for MDS, which considers hematologic parameters, cytogenetic abnormalities, and somatic gene mutations. The IPSS-M score is personalized and can be obtained using a web-based calculator that returns not only the individual score but also the expected leukemia-free survival, overall survival, and risk of AML transformation. Providing an efficient risk stratification of patients with MDS, the IPSS-M represents a valuable tool for individual risk assessment and treatment decisions.

Recent Clinical and Molecular Advances for the Classification of Myelodysplastic Neoplasms.

Several major updates have recently occurred for the NCCN Guidelines for Myelodysplastic Syndromes (MDS) based on a number of prominent articles that have particular clinical and biologic impact for the field. These changes, which have been included in the current iteration of the NCCN Guidelines (Version 1.2023), include the WHO 2022 classification of MDS as well as the ICC suggestions for same. In addition, the molecular underpinning of MDS has been greatly updated with the generation of the Molecular International Prognostic Scoring System (IPSS-M) and an improved understanding to the prognostic implications of mutated TP53 subtypes, which are additive to the revised IPSS (IPSS-R) for stratification and management of patients with MDS. This report emphasizes the major components of the relevant changes to serve as a guide for therapeutic decision-making for patients with MDS.

The International Consensus Classification of myelodysplastic syndromes and related entities.

The International Consensus Classification (ICC) of myeloid neoplasms and acute leukemia has updated the classification of myelodysplastic syndromes (MDSs) and placed MDS in a broader group of clonal cytopenias that includes clonal cytopenia of undetermined significance (CCUS) and related entities. Although subject to some interobserver variability and lack of specificity, morphologic dysplasia remains the main feature that distinguishes MDS from other clonal cytopenias and defines MDS as a hematologic malignancy. The ICC has introduced some changes in the definition of MDS whereby some cases categorized as MDS based on cytogenetic abnormalities are now classified as CCUS, while SF3B1 and multi-hit TP53 mutations are now considered to be MDS-defining in a cytopenic patient. The ICC has also recognized several cytogenetic and molecular abnormalities that reclassify some cases of MDS with excess blasts as acute myeloid leukemia (AML) and has introduced a new MDS/AML entity that encompasses cases with 10-19% blasts that lie on the continuum between MDS and AML. Two new genetically defined categories of MDS have been introduced: MDS with mutated SF3B1 and MDS with mutated TP53, the latter requiring bi-allelic aberrations in the TP53 gene. The entity MDS, unclassifiable has been eliminated. These changes have resulted in an overall simplification of the MDS classification scheme from 8 separate entities (including 1 that was genetically defined) in the revised 4th edition WHO classification to 7 separate entities (including 3 that are genetically defined) in the ICC.

Outcomes and molecular profile of oligomonocytic CMML support its consideration as the first stage in the CMML continuum

AbstractPatients with oligomonocytic chronic myelomonocytic leukemia (OM-CMML) are currently classified according to the 2017 World Health Organization myelodysplastic syndromes classification. However, recent data support considering OM-CMML as a specific subtype of chronic myelomonocytic leukemia (CMML), given their similar clinical, genomic, and immunophenotypic profiles. The main purpose of our study was to provide survival outcome data of a well-annotated series of 42 patients with OM-CMML and to compare them to 162 patients with CMML, 120 with dysplastic type (D-CMML), and 42 with proliferative type (P-CMML). OM-CMML had significantly longer overall survival (OS) and acute myeloid leukemia–free survival than did patients with CMML, considered as a whole group, and when compared with D-CMML and P-CMML. Moreover, gene mutations associated with increased proliferation (ie, ASXL1 and RAS-pathway mutations) were identified as independent adverse prognostic factors for OS in our series. We found that at a median follow-up of 53.47 months, 29.3% of our patients with OM-CMML progressed to D-CMML, and at a median follow-up of 46.03 months, 28.6% of our D-CMML group progressed to P-CMML. These data support the existence of an evolutionary continuum of OM-CMML, D-CMML, and P-CMML. In this context, we observed that harboring more than 3 mutated genes, carrying ASXL1 mutations, and a peripheral blood monocyte percentage >20% significantly predicted a shorter time of progression of OM-CMML into overt CMML. These variables were also detected as independent adverse prognostic factors for OS in OM-CMML. These data support the consideration of OM-CMML as the first evolutionary stage within the proliferative continuum of CMML.

Myelodysplastic Syndromes and Modalities of Treatment: An Updated Literature Review.

Myelodysplastic syndromes (MDS) represent a large group of rare and diverse clonal stem cell disorders. These are classified into several different phenotypes and typically arise following a multistep genetic process, whereby genetic mutations alter the DNA damage and cellular stress responses, impacting transcription, RNA splicing, epigenetics, and cytokine signaling. However, despite the advances made regarding molecular pathophysiology and prognostic criteria and the influx of new treatment modalities, management is primarily based on prognostic scores, such as the Revised International Prognostic Scoring System. This poses a significant challenge to current healthcare professionals due to poor comprehension of the underlying pathophysiology. Hence, this review integrates the latest research and treatment modalities for MDS and discusses the different genetic mutations outlined in the revised World Health Organization 2016 MDS classification system and the associated treatment modalities. Additionally, future directions of research and clinical management of MDS are discussed.

Flow Cytometric Detection of the Ki-67 Proliferation Index and the Bcl-2 Anti-Apoptotic Index in Myelodysplastic Syndromes and Acute Myeloid Leukemia, and Their Clinical Implications

Introduction: Standardization of the detection and quantification of leukocyte differentiation markers by the EuroFlow Consortium has led to a major step forward in the integration of flow cytometry in classification of myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). To further advance the integration and objectification of flow cytometry for characterization of these malignancies, more dynamic parameters assessing cell behavioral characteristics could prove useful, such as proliferative and (anti-)apoptotic markers. Proliferation and (anti-)apoptosis are processes that are tightly related to the pathogenesis, progression and chemo-/immunotherapy response of cancers. As a result, proliferation and (anti-)apoptotic markers have proven their value as objective parameters in the field of histopathology for diagnostic and prognostic applications in solid tumors and lymphoma. Although use of proliferative and (anti-)apoptotic markers as objective parameters in the diagnostic process of MDS and AML was studied in the past decades, this did not result in the incorporation of these biomarkers in their clinical diagnosis. The recent developments in flow cytometric analyses now allow the quantification of proliferative and (anti-)apoptotic fractions at the level of individual maturing bone marrow cells. Therefore, we aim to determine the Ki-67 proliferation indices and Bcl-2 anti-apoptotic indices in maturing bone marrow cells in order to assess whether these parameters could have future clinical implications for the diagnostic work-up of MDS and AML.Methods: Fifty bone marrow aspirates from femoral heads of non-malignant cases, 20 aspirates of MDS patients and 20 aspirates of AML were included in this study. Ten-color flow cytometry in combination with a software-based maturation tool was used for analysis of the Ki-67 proliferative and Bcl-2 anti-apoptotic indices of blast cells and during the erythro-, myelo-, and monopoiesis.Results: Ki-67 proliferative indices of blast cells and immature erythroid, myeloid and monocytic cells were significantly lower in MDS patients compared to the non-malignant cases, while the Bcl-2 anti-apoptotic indices were significantly elevated in these cells. Furthermore, the Bcl-2 anti-apoptotic indices were also increased in mature erythroid, myeloid and monocytic cells of MDS patients. The decreased Ki-67 proliferative indices and increased Bcl-2 anti-apoptotic indices in blast cells and erythroid, myeloid and monocytic cells were even more prominently observed in AML patients.Conclusions: The lowered Ki-67 proliferative indices and elevated Bcl-2 anti-apoptotic indices in blast cells and immature progenitor cells led to a better understanding of the pathophysiology of MDS and AML, and explained the low chemotherapy response of these patients. Side-effects of such therapies can also be explained by the Ki-67 proliferation indices and Bcl-2 anti-apoptotic indices. Moreover, the increase of the Bcl-2 anti-apoptotic fraction is an important factor in the progression of MDS to AML. Future studies on the clinical applications of these parameters for MDS and AML are necessary and can include many applications, such as prediction of chemo-/immunotherapy response, diagnostic and prognostic applications. DisclosuresRamaekers: Nordic-MUbio: Current Employment.

Novel Prediction Models for Myelodysplastic Syndromes Using Machine Learning

Novel Prediction Models for Myelodysplastic Syndromes Using Machine Learning

A Focus on Phenotype and Genotype: Racial /Ethnic Disparities in Myelodysplastic Syndromes

Background: There is a paucity of research on racial and ethnic disparities in myelodysplastic syndromes (MDS). Research focused on racial and ethnic disparities for MDS is essential to improve knowledge and understanding to deliver racial and ethnic sensitive care. There are limited studies that delineate the incidence of cytogenetic and molecular features of MDS by race and ethnicity (Yan, et al. 2021, Ramadan, et al.,2016). The aim of this abstract is to report the difference in clinical phenotype, genotype and outcomes of White, Black and Hispanics from a large MDS data base.Methods: Adult patients were identified through the Moffitt Cancer Center MDS data base and divided into racial/ethnic categories. Fisher exact test and chi-square tests were used to compare categorical variables. Univariate survival analysis was estimated using the Kaplan-Meier method.Results: From analysis of 4414 patients with MDS, 4131 (93%) were White, 116 (3%) Black and 167 (4%) Hispanic. Table-1 summarizes baseline characteristics. There were more Black and Hispanic women diagnosed with MDS (p < .001). Black and Hispanic patients were younger at diagnosis (p<0.01), Hispanic patients had a lower platelet count at baseline (p=0.02). There were no racial differences in WHO 2016 MDS classification or disease risk according to R-IPSS. Black MDS patients had less complex karyotype (p<0.05) while abnormalities in chromosome 5 were more common in White patients 785(19.6%, p<0.05).Table-2 summarizes somatic mutations (SM) landscape among the different racial groups, IDH2 SM (p=0. 01) and NPM-1 SM (p=.004) were more common in Black MDS patients. MPL (p < 0.005) was observed more frequently among Hispanic patients.There was no difference in response to any modality of treatment based on race. Hispanic patients were more likely to undergo allogeneic hematopoietic stem cell transplant 50 (29.9%, p<0.01). Clinical trial participation rates among the groups were similar.The median overall survival (mOS) was 35 months (mo), 31 mo, and 52.5 mo for White, Black and Hispanic patients respectively, p= .01 shown in Figure 1. For very low/low R-IPSS the mOS was 67.6, 52 and 93 mo respectively, p= .028, Figure 2a. For intermediate risk R-IPSS the mOS was 33, 30 and 51 mo respectively, p=0.2, and for high/very high-risk R-IPSS the mOS was 16.8, 21.7, and 25 mo respectively, p=.025. See Figures 2b and 2c. There was no difference in rate of AML transformationConclusions: This large retrospective study revealed racial/ethnic differences in clinical and molecular features of MDS. Hispanic patients had better overall survival. Continued research in this area is recommended to better understand the phenotype and genotype of patients from diverse ethnic/racial backgrounds.Acknowledgement of Funding: NINR Grant # 1K23NR018488-01A [Display omitted] DisclosuresTinsley-Vance: Novartis: Consultancy; Celgene/BMS: Consultancy, Speakers Bureau; Taiho: Consultancy; Fresenius Kabi: Consultancy; Incyte: Consultancy, Speakers Bureau; Astellas: Speakers Bureau; Abbvie: Honoraria; Jazz: Consultancy, Speakers Bureau. Padron: Stemline: Honoraria; Blueprint: Honoraria; Kura: Research Funding; Taiho: Honoraria; Incyte: Research Funding; BMS: Research Funding. Sweet: Astellas: Consultancy, Membership on an entity's Board of Directors or advisory committees; Novartis: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Meyers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; AROG: Membership on an entity's Board of Directors or advisory committees; Gilead: Membership on an entity's Board of Directors or advisory committees. Lancet: Celgene/BMS: Consultancy; BerGenBio: Consultancy; AbbVie: Consultancy; Daiichi Sankyo: Consultancy; ElevateBio Management: Consultancy; Millenium Pharma/Takeda: Consultancy; Astellas: Consultancy; Agios: Consultancy; Jazz: Consultancy. Kuykendall: PharmaEssentia: Honoraria; Novartis: Honoraria, Speakers Bureau; Incyte: Consultancy; Prelude: Research Funding; CTI Biopharma: Honoraria; Celgene/BMS: Honoraria, Speakers Bureau; BluePrint Medicines: Honoraria, Speakers Bureau; Abbvie: Honoraria; Protagonist: Consultancy, Membership on an entity's Board of Directors or advisory committees, Research Funding. Sallman: Incyte: Speakers Bureau; Bristol-Myers Squibb: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Takeda: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Shattuck Labs: Membership on an entity's Board of Directors or advisory committees; Aprea: Membership on an entity's Board of Directors or advisory committees, Research Funding; Syndax: Membership on an entity's Board of Directors or advisory committees; AbbVie: Membership on an entity's Board of Directors or advisory committees; Agios: Membership on an entity's Board of Directors or advisory committees; Magenta: Consultancy; Intellia: Membership on an entity's Board of Directors or advisory committees; Kite: Membership on an entity's Board of Directors or advisory committees. Komrokji: AbbVie: Consultancy; Geron: Consultancy; BMSCelgene: Consultancy, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Taiho Oncology: Membership on an entity's Board of Directors or advisory committees; PharmaEssentia: Membership on an entity's Board of Directors or advisory committees; Acceleron: Consultancy; Novartis: Consultancy, Honoraria, Membership on an entity's Board of Directors or advisory committees; Jazz: Consultancy, Speakers Bureau.