WHO-defined 'myelodysplastic syndrome with isolated del(5q)' in 88 consecutive patients: survival data, leukemic transformation rates and prevalence of JAK2, MPL and IDH mutations

Low dose lenalidomide versus placebo in non-transfusion dependent patients with low risk, del(5q) myelodysplastic syndromes (SintraREV): a randomised, double-blind, phase 3 trial

BACKGROUND

Lenalidomide is the standard of care for patients who are transfusion dependent with chromosome 5q deletion (del[5q]) myelodysplastic syndromes. In the SintraREV trial, we aimed to investigate whether an early intervention of low lenalidomide doses for 2 years could delay transfusion dependency in patients with anaemia who were not transfusion dependent.

METHODS

This randomised, double-blind, phase 3 trial, was conducted at 22 sites (University Hospitals) in Spain, France, and Germany. Eligible patients were aged 18 years or older diagnosed with low-risk or intermediate-1-risk del(5q) myelodysplastic syndromes with non-transfusion-dependent anaemia (according to the IPSS), were erythropoietin-stimulating agents naive, and had an ECOG performance status of 2 or less. Patients were randomly assigned (2:1) by means of a telephone system to receive lenalidomide 5 mg daily in 28-day cycles versus placebo for 2 years. The primary endpoint was time to transfusion dependency based on blinded independent central review. Analysis were by intent-to-treat (ITT) and evaluable population. Safety analyses included all participants who received at least one dose of treatment. This trial is registered with ClinicalTrials.gov (NCT01243476) and EudraCT (2009-013619-36) and is complete.

FINDINGS

Between Feb 15, 2010, and Feb 21, 2018, 61 patients were randomly assigned to receive lenalidomide (n=40; two did not receive treatment) or placebo (n=21). The median age was 72·2 (IQR 65·4-81·9) years, 50 (82%) patients were female, and 11 (18%) were male. The median follow-up time was 60·6 (IQR 32·1-73·9) months. Regarding primary endpoint, median time to transfusion dependency was not reached (95% CI not applicable) in the lenalidomide group versus 11·6 months (95% CI 0·00-30·11) in the placebo group (p=0·0027). Lenalidomide significantly reduced the risk of transfusion dependency by 69·8% (hazard ratio 0·302, 95% CI 0·132-0·692; p=0·0046). The most frequent treatment-related adverse event was neutropenia, occurring in 24 (63%) of 38 patients in the lenalidomide group (grade 3 and 4 in 17 [45%] patients and one [3%], respectively) and in four (19%) of 21 patients in the placebo group (grade 3 in one [5%] patient). Thrombocytopenia was detected in seven (18%) of 38 patients receiving lenalidomide (grade 3 in two [5%] patients). Regarding the non-haematological toxicity, skin disorders (rash nine [23%] of 38 patients) were the most frequently described toxicities among patients receiving lenalidomide, being grade 3 in one (3%) of 38 patients. 19 serious adverse events were reported in 13 patients, 18 in the lenalidomide group and one in the placebo group, five of which were potentially related to the study drug. No treatment-related deaths were identified.

INTERPRETATION

An early approach with low doses of lenalidomide across two years delays the time to transfusion dependency and improves the rate and quality of the responses, with a manageable safety profile in patients who are non-transfusion dependent with del(5q) low-risk myelodysplastic syndromes.

FUNDING

Bristol Myers Squibb.

Diagnostic challenges and proposed classification of myeloid neoplasms with overlapping features of thrombocytosis, ring sideroblasts and concurrent del(5q) and SF3B1 mutations

Not available.

Emergence of TP53 mutation during lenalidomide therapy of myelodysplastic syndrome with del(5q) and its subsequent disappearance following salvage therapy with decitabine

Not available.

TP53 variant allele frequency and therapy-related setting independently predict survival in myelodysplastic syndromes with del(5q)

Among 210 patients with myelodysplastic syndromes (MDSs) with del(5q), molecular information was available at diagnosis or at least 3 months before leukaemic transformation in 146 cases. Multivariate analysis identified therapy-related setting (p = 0.02; HR 2.3) and TP53 variant allele frequency (VAF) ≥22% (p < 0.01; HR 2.8), but not SF3B1 mutation (p = 0.65), as independent risk factors for survival. Median survival was 11.7 versus 4 years (5/10-year survival 73%/52% vs. 42%/14%) in the absence (N = 112) versus presence (N = 34) of ≥1 risk factors; leukaemia-free survival was affected by TP53 VAF ≥22% (p < 0.01). Such information might inform treatment decision-making in MDS-del(5q) regarding allogeneic stem cell transplant.

The Genetic Landscape of Myelodysplastic Neoplasm Progression to Acute Myeloid Leukemia

Myelodysplastic neoplasm (MDS) represents a heterogeneous group of myeloid disorders that originate from the hematopoietic stem and progenitor cells that lead to the development of clonal hematopoiesis. MDS was characterized by an increased risk of transformation into acute myeloid leukemia (AML). In recent years, with the aid of next-generation sequencing (NGS), an increasing number of molecular aberrations were discovered, such as recurrent mutations in FLT3, NPM1, DNMT3A, TP53, NRAS, and RUNX1 genes. During MDS progression to leukemia, the order of gene mutation acquisition is not random and is important when considering the prognostic impact. Moreover, the co-occurrence of certain gene mutations is not random; some of the combinations of gene mutations seem to have a high frequency (ASXL1 and U2AF1), while the co-occurrence of mutations in splicing factor genes is rarely observed. Recent progress in the understanding of molecular events has led to MDS transformation into AML and unraveling the genetic signature has paved the way for developing novel targeted and personalized treatments. This article reviews the genetic abnormalities that increase the risk of MDS transformation to AML, and the impact of genetic changes on evolution. Selected therapies for MDS and MDS progression to AML are also discussed.

JAK2 Mutations Are Rare and Diverse in Myelodysplastic Syndromes: Case Series and Review of the Literature

OBJECTIVES

To investigate and characterize JAK2 mutations in myelodysplastic syndrome (MDS), we present three cases with diverse JAK2 mutations and review the literature.

METHODS

The institutional SoftPath software was used to find MDS cases between January 2020 and April 2022. The cases with a diagnosis of a myelodysplastic/myeloproliferative overlap syndrome including MDS/MPN with ring sideroblasts and thrombocytosis were excluded. The cases with molecular data by next generation sequencing looking for gene aberrations commonly seen in myeloid neoplasms were reviewed for the detection of JAK2 mutations including variants. A literature review on the identification, characterization, and significance of JAK2 mutations in MDS was performed.

RESULTS

Among 107 cases of the MDS reviewed, a JAK2 mutation was present in three cases, representing 2.8% of the overall cases. A JAK2 V617F mutation was found in one case representing slightly less than 1% of all the MDS cases. In addition, we found JAK2 R564L and JAK2 I670V point mutation variants to be associated with a myelodysplastic phenotype.

CONCLUSIONS

JAK2 mutations in MDS are rare and represent less than 3% of cases. It appears that JAK2 variant mutations in MDS are diverse and further studies are needed to understand their role in the phenotype and prognosis of the disease.

Myelodysplastic Syndromes with Isolated del(5q): Value of Molecular Alterations for Diagnostic and Prognostic Assessment

Myelodysplastic syndromes (MDS) are a group of clonal hematological neoplasms characterized by ineffective hematopoiesis in one or more bone marrow cell lineages. Consequently, patients present with variable degrees of cytopenia and dysplasia. These characteristics constitute the basis for the World Health Organization (WHO) classification criteria of MDS, among other parameters, for the current prognostic scoring system. Although nearly half of newly diagnosed patients present a cytogenetic alteration, and almost 90% of them harbor at least one somatic mutation, MDS with isolated del(5q) constitutes the only subtype clearly defined by a cytogenetic alteration. The results of several clinical studies and the advances of new technologies have allowed a better understanding of the biological basis of this disease. Therefore, since the first report of the "5q- syndrome" in 1974, changes and refinements have been made in the definition and the characteristics of the patients with MDS and del(5q). Moreover, specific genetic alterations have been found to be associated with the prognosis and response to treatments. The aim of this review is to summarize the current knowledge of the molecular background of MDS with isolated del(5q), focusing on the clinical and prognostic relevance of cytogenetic alterations and somatic mutations.

Diagnosis and Treatment of Myelodysplastic Syndromes: A Review

IMPORTANCE

Myelodysplastic neoplasms (MDS), formerly known as myelodysplastic syndromes, are clonal hematopoietic malignancies that cause morphologic bone marrow dysplasia along with anemia, neutropenia, or thrombocytopenia. MDS are associated with an increased risk of acute myeloid leukemia (AML). The yearly incidence of MDS is approximately 4 per 100 000 people in the United States and is higher among patients with advanced age.

OBSERVATIONS

MDS are characterized by reduced numbers of peripheral blood cells, an increased risk of acute myeloid leukemia transformation, and reduced survival. The median age at diagnosis is approximately 70 years, and the yearly incidence rate increases to 25 per 100 000 in people aged 65 years and older. Risk factors associated with MDS include older age and prior exposures to toxins such as chemotherapy or radiation therapy. MDS are more common in men compared with women (with yearly incidence rates of approximately 5.4 vs 2.9 per 100 000). MDS typically has an insidious presentation, consisting of signs and symptoms associated with anemia, thrombocytopenia, and neutropenia. MDS can be categorized into subtypes that are associated with lower or higher risk for acute myeloid leukemia transformation and that help with therapy selection. Patients with lower-risk MDS have a median survival of approximately 3 to 10 years, whereas patients with higher-risk disease have a median survival of less than 3 years. Therapy for lower-risk MDS is selected based on whether the primary clinical characteristic is anemia, thrombocytopenia, or neutropenia. Management focuses on treating symptoms and reducing the number of required transfusions in patients with low-risk disease. For patients with lower-risk MDS, erythropoiesis stimulating agents, such as recombinant humanized erythropoietin or the longer-acting erythropoietin, darbepoetin alfa, can improve anemia in 15% to 40% of patients for a median of 8 to 23 months. For those with higher-risk MDS, hypomethylating agents such as azacitidine, decitabine, or decitabine/cedazuridine are first-line therapy. Hematopoietic cell transplantation is considered for higher-risk patients and represents the only potential cure.

CONCLUSIONS AND RELEVANCE

MDS are diagnosed in approximately 4 per 100 000 people in the United States and are associated with a 5-year survival rate of approximately 37%. Treatments are tailored to the patient's disease characteristics and comorbidities and range from supportive care with or without erythropoiesis-stimulating agents for patients with low-risk MDS to hypomethylating agents, such as azacitidine or decitabine, for patients with higher-risk MDS. Hematopoietic cell transplantation is potentially curative and should be considered for patients with higher-risk MDS at the time of diagnosis.

A Systematic Literature Review of the Relationship between Serum Ferritin and Outcomes in Myelodysplastic Syndromes

Anemia is the most common form of cytopenia in patients with myelodysplastic syndromes (MDS), who require chronic red blood cell transfusions and may present high serum ferritin (SF) levels as a result of iron overload. To better understand the potential effects of high SF levels, we conducted a systematic literature review (SLR) to identify evidence on the relationship between SF levels and clinical, economic, or humanistic outcomes in adult patients with MDS. Of 267 references identified, 21 were included. No studies assessing SF levels and their relationship with humanistic or economic outcomes were identified. Increased SF levels were an indicator of worse overall survival and other worsened outcomes; however, the association was not consistently significant. SF levels were a significant prognostic factor for relapse incidence of MDS and showed a significant positive correlation with number of blood units transfused but were not associated with progression to acute myeloid leukemia or the time to transformation. Higher SF levels were also an indicator of a lower likelihood of leukemia-free survival, relapse-free survival, and event-free survival. The SLR suggests that SF levels are associated with clinical outcomes in MDS, with higher levels correlated with number of blood units transfused, frequently indicating worse outcomes.

Age, Blasts, Performance Status and Lenalidomide Therapy Influence the Outcome of Myelodysplastic Syndrome With Isolated Del(5q): A Study of 58 South American Patients

BACKGROUND

Myelodysplastic Syndrome (MDS) with isolated deletion 5q is associated with a low risk to leukemic evolution and long overall survival (OS); it comprises 3%-4.5% of MDS cases in Latin America classified according to the World Health Organization 2008. This study aims to describe clinical, laboratory and the outcome of patients according to the newest World Health Organization 2016 proposal.

METHODS

We retrospectively reviewed patients from four Brazilian (BR) and four Argentinean (AR) centers diagnosed between 1999 and 2019.

RESULTS

The 58 patients (16-AR and 42-BR) presented a median age of 67 (IQR 61-75) years old, women predominance (70.7%) and transfusion dependency (62.5%) at diagnosis. Median hemoglobin level was 8.1g/dL, 27.5% and 44.4% presented thrombocytosis and neutropenia, respectively. Bone marrow (BM) was predominantly hypercellular (43.1%) with 66% showing dysplasia >1 lineage and 37.9% with >2% of blasts. Deletion 5q was mostly isolated (79.3%) and a variety of abnormalities were observed in remaining cases. Most patients were treated with erythropoietin-stimulating agents (ESA), 18 with lenalidomide and 15 with thalidomide. Median follow-up was 7.6 years, with a median OS of 3.5 years and an 8-years leukemic evolution rate of 18.4%. Multivariate analysis showed that age >75 years (HR 2.19), ECOG ≥2 (HR 5.76), BM blasts >2% (HR 2.92) and lenalidomide treatment (HR 0.25) independently influenced the OS.

CONCLUSION

Older age, worse performance status and higher percentage of blasts, that can be easily assessed, were associated to a worse prognosis. Also, our results corroborate the protective influence of lenalidomide in terms of OS in this South American series.

Myelodysplastic syndromes and overlap syndromes

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematological neoplasms characterized by ineffective hematopoiesis, morphologic dysplasia, and cytopenia. MDS overlap syndromes include various disorders, such as myelodysplastic/myeloproliferative neoplasms and hypoplastic MDS with aplastic anemia characteristics. MDS overlap syndromes share the characteristics of other diseases, which make differential diagnoses challenging. Advances in genomic studies have led to the discovery of frequent mutations in MDS and overlap syndromes; however, most of the mutations are not specific for the diagnosis of these diseases. The molecular characteristics of the overlap syndromes usually do not show a just "in-between" form but rather heterogeneous features. Established diagnostic criteria for these diseases based on clinical, morphologic, and laboratory features are still useful when combined with genomic data. It is expected that further studies for MDS and overlap syndromes will place emphasis on the roles of mutations as therapeutic targets and prognostic indicators.

Traipsing Through Muddy Waters: A Critical Review of the Myelodysplastic Syndrome/Myeloproliferative Neoplasm (MDS/MPN) Overlap Syndromes

Myelodysplastic syndrome/Myeloproliferative neoplasms (MDS/MPNs) are molecularly complex, clinically heterogeneous diseases that exhibit proliferative and dysplastic features. Diagnostic criteria use clinical, pathologic, and genomic features to distinguish between disease entities, though considerable clinical and genetic overlap persists. MDS/MPNs are associated with a poor prognosis, save for MDS/MPN with ring sideroblasts and thrombocytosis, which can behave more indolently. The current treatment approach is risk-adapted and symptom-directed and largely extrapolated from experience in MDS or MPN. Gene sequencing has demonstrated frequent mutations involving signaling, epigenetic, and splicing pathways, which present numerous therapeutic opportunities for clinical investigation.

Loss of 5q in myeloid malignancies - A gain in understanding of biological and clinical consequences

Hemizygous interstitial or terminal deletion of the long arm of chromosome 5 [del(5q)] is a recurrent cytogenetic abnormality in myeloid malignancies, including myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). These deletions cause loss of a large contiguous chromosomal region encompassing more than 30 genes, which results in disease through haploinsufficiency of one or more genes including RPS14. In MDS, del(5q) in isolation is a lower-risk cytogenetic anomaly and is sometimes associated with a unique clinicopathological phenotype, but in AML it represents a higher-risk lesion, often denoting secondary AML arising from prior MDS. Lenalidomide effectively targets the del(5q)-bearing clone in MDS, resulting in sustained erythroid transfusion independence in most patients and cytogenetic remission in a subset of treated patients. Since the initial regulatory approval of lenalidomide for del(5q) MDS in 2005, translational research endeavors in del(5q)-associated myeloid malignancies have improved our understanding of how allelic haploinsufficiency underlies both the hematological phenotype and selective sensitivity to lenalidomide therapy. This review will focus on the molecular pathogenesis of del(5q) in myeloid malignancies, clinical development of lenalidomide and emerging data on lenalidomide-refractory del (5q) MDS, and possible novel targeted therapeutic strategies.

Myelodysplastic syndromes: a review of therapeutic progress over the past 10 years

INTRODUCTION

Myelodysplastic syndromes (MDS) represent a range of bone marrow disorders, with patients affected by cytopenias and risk of progression to AML. There are limited therapeutic options available for patients, including hypomethylating agents (azacitidine/decitabine), growth factor support, lenalidomide, and allogeneic stem cell transplant.

AREAS COVERED

This review provides an overview of the progress made over the past decade for emerging therapies for lower- and higher-risk MDS (MDS-HR). We also cover advances in prognostication, supportive care, and use of allogeneic SCT in MDS.

EXPERT OPINION

While there have been no FDA-approved therapies for MDS in the past decade, we anticipate the approval of luspatercept based on results from the MEDALIST trial for patients with lower-risk MDS (MDS-LR) and ringed sideroblasts who have failed or are ineligible for erythropoiesis stimulating agents (ESAs). With growing knowledge of the biologic and molecular mechanisms underlying MDS, it is anticipated that new therapies will be approved in the coming years.

Myeloid neoplasm with isolated del(5q) and the MPLW515L mutation fulfills the WHO diagnostic criteria for ET

A 70-year-old male was referred to our hospital for marked thrombocytosis without anemia. The patient simultaneously presented with an MPL W515L mutation, one of the major driver mutations in essential thrombocythemia (ET), and deletion of 5q, a characteristic cytogenetic abnormality in myelodysplastic syndrome (MDS). Bone marrow examination showed a combination of both mature hyperlobulated megakaryocytes, as found in ET, and small hypolobulated megakaryocytes, typically found in MDS with del(5q). The present case is consistent with the recently proposed category of myeloid neoplasms with isolated del(5q) and an MPN driver mutation.

Acute myeloid leukemia with isolated del(5q) is associated with IDH1/IDH2 mutations and better prognosis when compared to acute myeloid leukemia with complex karyotype including del(5q)

Myelodysplastic syndrome with isolated del(5q) is a well-recognized entity with a relatively favorable prognosis. Isolated del(5q) in acute myeloid leukemia is rare and acute myeloid leukemia cases with isolated del(5q) are not well characterized. Del(5q) has been shown to be a poor prognostic marker in acute myeloid leukemia based on multivariable analysis in large cohort studies, which contained mostly cases with del(5q) in the context of multiple chromosomal abnormalities. To further characterize acute myeloid leukemia with isolated del(5q), clinicopathologic characterization including mutation analysis was performed. During a 10-year period, we identified 12 cases of acute myeloid leukemia with isolated del(5q), 7 cases of acute myeloid leukemia with del(5q) plus one additional chromosome abnormality not involving chromosome 7, as well as two control groups composed of 124 cases of acute myeloid leukemia with complex karyotype including del(5q), and 40 cases of myelodysplastic syndrome with isolated del(5q). At diagnosis, cases of acute myeloid leukemia with isolated del(5q) had higher platelet counts (p = 0.044), hemoglobin (p = 0.011), and mean corpuscular volume (p = 0.017) compared with cases of acute myeloid leukemia with complex karyotype including del(5q). Acute myeloid leukemia with isolated del(5q) was less likely therapy-related (p = 0.037), more likely to have IDH1/IDH2 mutations (p = 0.009), and less likely to have TP53 mutations (p = 0.005) when compared to acute myeloid leukemia with complex karyotype including del(5q). Acute myeloid leukemia with isolated del(5q) also showed longer overall survival than acute myeloid leukemia with complex karyotype cases including del(5q) (p = 0.004). In summary, acute myeloid leukemia with isolated del(5q) appeared to show some distinct clinicopathologic and genomic features as compared to cases of acute myeloid leukemia with complex karyotype including del(5q).

Myelodysplastic/myeloproliferative neoplasms: are morphology and immunophenotyping still relevant?

The term myelodysplastic/myeloproliferative neoplasm (MDS/MPN) refers to a group of clonal hematopoietic neoplasms with overlapping clinical, morphologic and genetic myelodysplastic and myeloproliferative features observed at the time of first presentation. Impaired hematopoiesis morphologically associated with evidence of myelodysplasia manifests clinically with cytopenia/s. Simultaneously, myeloproliferation is seen within the bone marrow and leads to cytosis in the peripheral blood. The diagnostic category of MDS/MPN encompasses a heterogeneous group of diseases which share similarities among them, but at the same time have distinct clinical and pathologic features and eventually diverse prognosis; such differences justify their separation in a classification scheme. In the era of genetic and genomic tests, their distinction from conventional myelodysplastic syndromes or myeloproliferative neoplasms still relies on close clinocopathological correlation, with evaluation of both peripheral blood and bone marrow samples being essential in this sense. A multiparametric integration of clinicopathologic data and cytogenetics and molecular genetics results is the preferred diagnostic approach.

Defining the Boundary Between Myelodysplastic Syndromes and Myeloproliferative Neoplasms

In this article we provide a practical and comprehensive review of myeloid neoplasms with overlapping myelodysplastic (MDS) and myeloproliferative (MPN) features, with emphasis on recent updates in classification, particularly the utility of morphologic, cytogenetic, and molecular findings in better defining and classifying these disease entities. We provide the reader with a summary of the most recent developments and updates that have helped further our understanding of the genomic landscape, clinicopathologic features, and prognostic elements of myeloid neoplasms with MDS/MPN features.

Refractory anemia with ring sideroblasts (RARS) and RARS with thrombocytosis: "2019 Update on Diagnosis, Risk-stratification, and Management"

DISEASE OVERVIEW

Ring sideroblasts (RS) are erythroid precursors with abnormal perinuclear mitochondrial iron accumulation. Two myeloid neoplasms defined by the presence of RS, include refractory anemia with ring sideroblasts (RARS), now classified under myelodysplastic syndromes with RS (MDS-RS) and RARS with thrombocytosis (RARS-T); now called myelodysplastic/myeloproliferative neoplasm with RS and thrombocytosis (MDS/MPN-RS-T).

DIAGNOSIS

MDS-RS is a lower-risk MDS, with single or multilineage dysplasia (SLD/MLD), <5% bone marrow (BM) blasts and ≥ 15% BM RS (≥5% in the presence of SF3B1 mutations). MDS/MPN-RS-T, now a formal entity in the MDS/MPN overlap syndromes, has diagnostic features of MDS-RS-SLD, along with a platelet count ≥450 × 10(9)/L and large atypical megakaryocytes.

MUTATIONS AND KARYOTYPE

Mutations in SF3B1 are seen in ≥80% of patients with MDS-RS-SLD and MDS/MPN-RS-T, and strongly correlate with the presence of BM RS; MDS/MPN-RS-T patients also demonstrate JAK2V617F, ASXL1, DNMT3A, SETBP1, and TET2 mutations. Cytogenetic abnormalities are uncommon in both.

RISK STRATIFICATION

Most patients with MDS-RS-SLD are stratified into lower-risk groups by the revised-IPSS. Disease outcome in MDS/MPN-RS-T is better than that of MDS-RS-SLD, but worse than that of essential thrombocythemia. Both diseases have a low risk of leukemic transformation.

TREATMENT

Anemia and iron overload are complications seen in both and are managed similar to lower-risk MDS and MPN. The advent of luspatercept, a first-in-class erythroid maturation agent will tremendously boost the ability to manage anemia. Aspirin therapy is reasonable in MDS/MPN-RS-T, especially in the presence of JAK2V617F, but the value of platelet-lowering drugs remains uncertain.

Lenalidomide induced durable remission in a patient with MDS/MPN-with ring sideroblasts and thrombocytosis with associated 5q- syndrome

We describe a patient with MDS/MPN with ring sideroblasts and thrombocytosis who had deletions of long arm of chromosome 5 (5q-) and chromosome 20 (20q-). Molecular studies showed an exon 9, frame shift mutation in the calreticulin (CALR) gene, and absence of mutations in JAK2, MPL, SETBP1 or SF3B1.

Treatment with lenalidomide resulted in durable clinical remission which has lasted 2 years.

Recurrent genetic defects on chromosome 5q in myeloid neoplasms

Background

Deletion of chromosome 5q (del(5q)) is the most common karyotypic abnormality in myeloid neoplasms.

Materials and Methods

To define the pathogenic molecular features associated with del(5q), next–generation sequencing was applied to 133 patients with myeloid neoplasms (MDS; N = 69, MDS/MPN; N = 5, sAML; N = 29, pAML; N = 30) with del(5q) as a sole abnormally or a part of complex karyotype and results were compared to molecular features of patients diploid for chr5.

Findings

A number of 5q genes with haploinsufficient expression and/or recurrent somatic mutations were identified; for these genes, CSNK1A1 and G3BP1 within the commonly deleted 5q region and DDX41 within a commonly retained region were most commonly affected by somatic mutations. These genes showed consistent haploinsufficiency in deleted cases; low expression/mutations of G3BP1 or DDX41 were associated with poor survival, likely due to decreased cellular function. The most common mutations on other chromosomes in patients with del(5q) included TP53, and mutations of FLT3 (ITD or TKD), NPM1 or TET2 and were mutually exclusive. Serial sequencing allowed for definition of clonal architecture and dynamics, in patients with exome sequencing allelic imbalance for informative SNPs facilitated simultaneous approximation of clonal size of del(5q) and clonal burden for somatic mutations.

Interpretation

Our results illuminate the spectrum of molecular defects characteristic of del(5q), their clinical impact and succession of stepwise evolution.

The 2016 revised World Health Organization definition of 'myelodysplastic syndrome with isolated del(5q)'; prognostic implications of single versus double cytogenetic abnormalities

The definition of the myelodysplastic syndrome (MDS) subtype 'MDS with isolated del(5q)' was expanded to include cases with one additional non-chromosome 7 based cytogenetic abnormality in the 2016 revised World Health Organization classification. This study applied the revised definition to a large primary MDS cohort, and evaluated the prognostic impact of the additional cytogenetic abnormality. Seventy-two of 1067 patients (7%) met the 'MDS with isolated del(5q)' criteria, 11 (1%) of whom had an additional cytogenetic abnormality. There was no survival difference between patients in whom del(5q) occurred alone, compared to those with one additional cytogenetic abnormality (P = 0·52).

Refractory anemia with ring sideroblasts (RARS) and RARS with thrombocytosis (RARS-T): 2017 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Ring sideroblasts (RS) are erythroid precursors with abnormal perinuclear mitochondrial iron accumulation. Two myeloid neoplasms defined by the presence of RS, include refractory anemia with ring sideroblasts (RARS), now classified under myelodysplastic syndromes with RS (MDS-RS) and RARS with thrombocytosis (RARS-T); now called myelodysplastic/myeloproliferative neoplasm with RS and thrombocytosis (MDS/MPN-RS-T).

DIAGNOSIS

MDS-RS is a lower risk MDS, with single or multilineage dysplasia (SLD/MLD), <5% bone marrow (BM) blasts and ≥15% BM RS (≥5% in the presence of SF3B1 mutations). MDS/MPN-RS-T, now a formal entity in the MDS/MPN overlap syndromes, has diagnostic features of MDS-RS-SLD, along with a platelet count ≥ 450 × 10(9)/L and large atypical megakaryocytes (similar to BCR-ABL1 negative MPN).

MUTATIONS AND KARYOTYPE

Mutations in SF3B1 are seen in ≥80% of patients with MDS-RS-SLD and MDS/MPN-RS-T, and strongly correlate with the presence of BM RS; MDS/MPN-RS-T patients also demonstrate JAK2V617F, ASXL1, DNMT3A, SETBP1, and TET2 mutations; with ASXL1/SETBP1 mutations adversely impacting survival. Cytogenetic abnormalities are uncommon in both diseases.

RISK STRATIFICATION

Most patients with MDS-RS-SLD are stratified into lower risk groups by the revised-International Prognostic Scoring System (R-IPSS). Disease outcome in MDS/MPN-RS-T is better than that of MDS-RS-SLD, but worse than that of essential thrombocythemia. Both diseases have a low risk of leukemic TREATMENT: Anemia and iron overload are complications seen in both and are managed similar to lower risk MDS and MPN. Aspirin therapy is reasonable in MDS/MPN-RS-T, especially in the presence of JAK2V617F, but the value of platelet-lowering drugs is uncertain.

Association between Transfusion Status and Overall Survival in Patients with Myelodysplastic Syndromes: A Systematic Literature Review and Meta-Analysis

INTRODUCTION

Multiple studies show that transfusion independence (TI) in myelodysplastic syndrome (MDS) has a positive impact on overall survival (OS). To assess this, a systematic review and meta-analysis of the association between TI and OS in patients with MDS was conducted (PROSPERO ID: CRD42014007264).

METHODS

Comprehensive searches of 5 key bibliographic databases were conducted and supplemented with additional search techniques. Included were studies that had recruited adults aged >18 years with MDS and had examined the impact of transfusion status on OS.

RESULTS

Fifty-five studies (89 citations) were included. The vast majority reported a statistically significant hazard ratio (HR) for OS in favor of TI patients or in patients who acquired TI after treatment. A random-effects meta-analysis was conducted. Patients classed as TI at baseline showed a 59% decrease in the risk of death compared with transfusion-dependent (TD) patients [HR 0.41; 95% credible interval (CrI) 0.29-0.56], and this effect did not appear to interact significantly with illness severity (interaction coefficient HR 1.38; 95% CrI 0.62-3.41). A meta-analysis of studies where patients acquired TI was not possible, but those studies consistently reported a survival benefit for those who acquired TI.

CONCLUSION

The findings revealed a 59% pooled reduction in mortality among TI patients when compared with TD patients.

Molecular and Cellular Mechanisms of Myelodysplastic Syndrome: Implications on Targeted Therapy

Myelodysplastic syndrome (MDS) is a group of heterogeneous clonal hematopoietic stem cell disorders characterized by cytopenia, ineffective hematopoiesis, and progression to secondary acute myeloid leukemia in high-risk cases. Conventional prognostication relies on clinicopathological parameters supplemented by cytogenetic information. However, recent studies have shown that genetic aberrations also have critical impacts on treatment outcome. Moreover, these genetic alterations may themselves be a target for treatment. The mutation landscape in MDS is shaped by gene aberrations involved in DNA methylation (TET2, DNMT3A, IDH1/2), histone modification (ASXL1, EZH2), the RNA splicing machinery (SF3B1, SRSF2, ZRSR2, U2AF1/2), transcription (RUNX1, TP53, BCOR, PHF6, NCOR, CEBPA, GATA2), tyrosine kinase receptor signaling (JAK2, MPL, FLT3, GNAS, KIT), RAS pathways (KRAS, NRAS, CBL, NF1, PTPN11), DNA repair (ATM, BRCC3, DLRE1C, FANCL), and cohesion complexes (STAG2, CTCF, SMC1A, RAD21). A detailed understanding of the pathogenetic mechanisms leading to transformation is critical for designing single-agent or combinatorial approaches in target therapy of MDS.

Cytogenetic and molecular abnormalities in chronic myelomonocytic leukemia

Chronic myelomonocytic leukemia (CMML) is a clonal stem cell disorder associated with peripheral blood monocytosis and an inherent tendency to transform to acute myeloid leukemia. CMML has overlapping features of myelodysplastic syndromes and myeloproliferative neoplasms. Clonal cytogenetic changes are seen in ~30%, whereas gene mutations are seen in >90% of patients. Common cytogenetic abnormalities include; trisomy 8, -Y, -7/del(7q), trisomy 21 and del(20q), with the Mayo-French risk stratification effectively risk stratifying patients based on cytogenetic abnormalities. Gene mutations frequently involve epigenetic regulators (TET2 ~60%), modulators of chromatin (ASXL1 ~40%), spliceosome components (SRSF2 ~50%), transcription factors (RUNX1 ~15%) and signal pathways (RAS ~30%, CBL ~15%). Of these, thus far, only nonsense and frameshift ASXL1 mutations have been shown to negatively impact overall survival. This has resulted in the development of contemporary, molecularly integrated (inclusive of ASXL1 mutations) CMML prognostic models, including Molecular Mayo Model and the Groupe Français des Myélodysplasies model. Better understanding of the prevalent genetic and epigenetic dysregulation has resulted in emerging targeted treatment options for some patients. The development of an integrated (cytogenetic and molecular) prognostic model along with CMML-specific response assessment criteria are much needed future goals.

Early lenalidomide treatment for low and intermediate-1 International Prognostic Scoring System risk myelodysplastic syndromes with del(5q) before transfusion dependence

Lenalidomide is approved for the treatment of transfusion-dependent (TD) del(5q) myelodysplastic syndromes (MDS). However, few data are available in patients with transfusion-independent (TI) del(5q) MDS. In the first, observational, part of this 2-part study, we assessed the impact of transfusion dependence on overall survival (OS) and non-leukemic death in untreated del(5q) MDS patients who were TD (n = 136), TI with hemoglobin (Hb) ≥10 mg/dL (n = 88), or TI with Hb <10 mg/dL (n = 96). In the second, interventional, part we assessed the quality-of-life (QoL) benefits and clinical efficacy of lenalidomide (10 mg/day) in 12 patients with TI del(5q) MDS and Hb <10 mg/dL. In the untreated population, OS was significantly longer in TI than in TD patients (TI [Hb ≥10 g/dL], 108 months; TI [Hb <10 g/dL], 77 months; TD, 44 months). Transfusion dependence also negatively impacted non-leukemic death rates. In the interventional part of the study, baseline Hb levels were found to correlate significantly with physical (R = 0.666, P = 0.035) and fatigue (R = 0.604, P = 0.049) QoL scores. Median physical QoL scores improved significantly after 12 weeks' treatment with lenalidomide (+12.5; P = 0.020). Evaluable TI patients experienced early increases in Hb levels, and all attained an erythroid response. Our findings suggest that TI patients with moderate anemia may benefit from early treatment with lenalidomide.

Polish experience of lenalidomide in the treatment of lower risk myelodysplastic syndrome with isolated del(5q)

Background

Lenalidomide has been approved for the treatment of lower-risk myelodysplastic syndrome (MDS) with 5q deletion (del(5q)). We present for the first time a retrospective analysis of low-risk MDS with isolated del5q treated with lenalidomide, outside the clinical trials.

Methods

36 red blood cell (RBC) transfusion-dependent patients have been included in the study. Patients received lenalidomide 10 mg/day on days 1–21 of 28-day cycles.

Results

91.7 % of patients responded to lenalidomide treatment: 72.2 % achieved erythroid response, 19.4 % achieved minor erythroid response and 8.4 % of patients did not respond to treatment. Response depended on number of previous treatment lines (p = 0.0101), International Prognostic System Score (IPSS; p = 0.0067) and RBC transfusion frequency (p = 0.0139). Median duration of response was 16 months (range 6–60 months). Treatment was well tolerated. We observed hematological toxicity (grade 3 and 4): neutropenia in 16 (44.4 %) patients and thrombocytopenia in 9 (25 %) patients. Two patients (5.5 %) progressed to high-risk MDS and two subsequent progressed to acute myeloid leukemia. A Kaplan-Meier estimate for overall survival at 5 years in the study group was 79.0 ± 8.8 %.

Conclusions

Lenalidomide in this group of patients was beneficial for the treatment of RBC transfusion-dependency with well-known safety profile.

Refractory anemia with ring sideroblasts and RARS with thrombocytosis

DISEASE OVERVIEW

Ring sideroblasts (RS) are erythroid precursors with abnormal perinuclear mitochondrial iron accumulation. Two myeloid neoplasms defined by the presence of RS, include refractory anemia with ring sideroblasts (RARS) and RARS with thrombocytosis (RARS-T).

DIAGNOSIS

RARS is a lower risk myelodysplastic syndrome (MDS) with dysplasia limited to the erythroid lineage, <5% bone marrow (BM) blasts and ≥15% BM RS. RARS-T is a provisional entity in the MDS/MPN (myeloproliferative neoplasm) overlap syndromes, with diagnostic features of RARS, along with a platelet count ≥450 × 10(9)/L and large atypical megakaryocytes similar to those observed in BCR-ABL1 negative MPN. Mutations and Karyotype: Mutations in the SF3B1 gene are seen in ≥80% of patients with RARS and RARS-T, and strongly correlate with the presence of BM RS; RARS-T patients have additional mutations such as, JAK2V617F (∼60%), MPL (<5%), and CALR (<5%). Cytogenetic abnormalities are uncommon in both RARS and RARS-T.

RISK STRATIFICATION

Most patients with RARS are stratified into lower risk groups by the International Prognostic Scoring System (IPSS) for MDS and the revised IPSS. Disease outcome in RARS-T is better than that of RARS, but worse than that of essential thrombocytosis. Both RARS and RARS-T have a low risk of leukemic transformation.

TREATMENT

Anemia and iron overload are complications in both diseases and are managed similar to lower risk MDS. Aspirin therapy is reasonable in RARS-T, especially in the presence of JAK2V617F, but the value of platelet-lowering drugs is uncertain. Case reports of RARS-T therapy with lenalidomide warrant additional studies.

Acquired somatic mutations of isocitrate dehydrogenases 1 and 2 (IDH1 and IDH2) in preleukemic disorders

Mutations of isocitrate dehydrogenase isoform 1 and 2 (IDH1 and IDH2) genes have been identified in glioblastoma and acute myeloid leukemia (AML). However, little is known about the molecular alterations of IDH genes in preleukemic disorders with a propensity to transform to AML. We performed polymerase chain reaction-denaturing high performance liquid chromatography (PCR-DHPLC) followed by direct sequencing to detect IDH mutations in 237 patients with myeloproliferative neoplasms (MPNs; n=108), myelodysplastic syndrome (MDS; n=22), paroxysmal nocturnal hemoglobinuria (PNH; n=41), and aplastic anemia (AA; n=66). No IDH1 R132 and IDH2 R172 mutations were identified in the entire cohort, whereas IDH1 G105G allele was detected in 4/108 MPN (3.70%), 2/22 MDS (9.09%), and 2/41 PNH (4.88%) patients. Three IDH2 R140Q mutations were found in 2/108 MPN (1.85%) and 1/22 MDS (4.54%) patients, while one IDH2 G145G allele was found in 0.92% (1/108) of MPN patients. Overall, our data suggest that IDH mutations are rare in the preleukemic disorders and may not be the major initial step in AML leukemogenesis.

Myelodysplastic disorders carrying both isolated del(5q) and JAK2(V617F) mutation: concise review, with focus on lenalidomide therapy

The concomitant presence of del(5q) and JAK2(V617F) mutation is an infrequent event which occurs in rare patients with peculiar cytogenetic, molecular, morphological and clinical features, resembling those of both myelodysplastic syndromes and myeloproliferative neoplasms. Lenalidomide may induce rapid, profound, and long-lasting responses in a subset of these patients. However, the mechanism(s) by which the drug acts in these conditions remain not completely elucidated. A new case report and a review of all cases published so far in this setting are provided. Furthermore, the possibility of categorizing - from a clinical, pathological, and biological point of view - for at least some of these patients as a potential distinct entity is discussed.

Extended survival and reduced risk of AML progression in erythroid-responsive lenalidomide-treated patients with lower-risk del(5q) MDS

Lenalidomide is the approved treatment for patients with red blood cell (RBC) transfusion-dependent lower-risk myelodysplastic syndromes (MDS) and chromosome 5q deletion (del(5q)). We report the long-term outcomes (median follow-up 3.2 years) in patients treated with lenalidomide in the MDS-003 trial. RBC transfusion independence (TI) ≥ 8 weeks was achieved in 97 of 148 treated patients (65.5%), with a median response duration of 2.2 years. Partial or complete cytogenetic response was achieved by 63 of 88 evaluable patients (71.6%). Median overall survival (OS) was longer in patients achieving RBC-TI ≥ 8 weeks (4.3 vs 2.0 years in non-responders; P<0.0001) or cytogenetic response (4.9 vs 3.1 years in non-responders; P=0.010). Time to acute myeloid leukemia (AML) progression was longer in patients achieving RBC-TI ≥ 8 weeks or any cytogenetic response versus non-responders (P=0.001 and P=0.0002, respectively). In a landmark multivariate analysis, RBC-TI ≥ 8 weeks was associated with prolonged OS (P<0.001) and a trend toward reduced relative risk of AML progression (P=0.080). Among these lower-risk MDS patients with del(5q), lenalidomide was associated with prolonged RBC-TI and cytogenetic responses, which were linked to improved OS and reduced risk of AML progression.

DNMT3A and IDH mutations in acute myeloid leukemia and other myeloid malignancies: associations with prognosis and potential treatment strategies

The development of effective treatment strategies for most forms of acute myeloid leukemia (AML) has languished for the past several decades. There are a number of reasons for this, but key among them is the considerable heterogeneity of this disease and the paucity of molecular markers that can be used to predict clinical outcomes and responsiveness to different therapies. The recent large-scale sequencing of AML genomes is now providing opportunities for patient stratification and personalized approaches to treatment that are based on individual mutational profiles. It is particularly notable that studies by The Cancer Genome Atlas and others have determined that 44% of patients with AML exhibit mutations in genes that regulate methylation of genomic DNA. In particular, frequent mutation has been observed in the genes encoding DNA methyltransferase 3A (DNMT3A), isocitrate dehydrogenase 1 (IDH1) and isocitrate dehydrogenase 2 (IDH2), as well as Tet oncogene family member 2. This review will summarize the incidence of these mutations, their impact on biochemical functions including epigenetic modification of genomic DNA and their potential usefulness as prognostic indicators. Importantly, the presence of DNMT3A, IDH1 or IDH2 mutations may confer sensitivity to novel therapeutic approaches, including the use of demethylating agents. Therefore, the clinical experience with decitabine and azacitidine in the treatment of patients harboring these mutations will be reviewed. Overall, we propose that understanding the role of these mutations in AML biology will lead to more rational therapeutic approaches targeting molecularly defined subtypes of the disease.

Atypical chronic myeloid leukemia is clinically distinct from unclassifiable myelodysplastic/myeloproliferative neoplasms

Atypical chronic myeloid leukemia (aCML) is a rare subtype of myelodysplastic/myeloproliferative neoplasm (MDS/MPN) largely defined morphologically. It is, unclear, however, whether aCML-associated features are distinctive enough to allow its separation from unclassifiable MDS/MPN (MDS/MPN-U). To study these 2 rare entities, 134 patient archives were collected from 7 large medical centers, of which 65 (49%) cases were further classified as aCML and the remaining 69 (51%) as MDS/MPN-U. Distinctively, aCML was associated with many adverse features and an inferior overall survival (12.4 vs 21.8 months, P = .004) and AML-free survival (11.2 vs 18.9 months, P = .003). The aCML defining features of leukocytosis and circulating myeloid precursors, but not dysgranulopoiesis, were independent negative predictors. Other factors, such as lactate dehydrogenase, circulating myeloblasts, platelets, and cytogenetics could further stratify MDS/MPN-U but not aCML patient risks. aCML appeared to have more mutated RAS (7/20 [35%] vs 4/29 [14%]) and less JAK2p.V617F (3/42 [7%] vs 10/52 [19%]), but was not statistically significant. Somatic CSF3R T618I (0/54) and CALR (0/30) mutations were not detected either in aCML or MDS/MPN-U. In conclusion, within MDS/MPN, the World Health Organization 2008 criteria for aCML identify a subgroup of patients with features clearly distinct from MDS/MPN-U. The MDS/MPN-U category is heterogeneous, and patient risk can be further stratified by a number of clinicopathological parameters.

Transfusion dependence development and disease evolution in patients with MDS and del(5q) and without transfusion needs at diagnosis

Patients with isolated del(5q) and MDS are considered to have good prognosis as compared to other MDS subtypes. Most patients suffered of anemia and 50% of them required transfusions at diagnosis. It is known that for patients with MDS and del(5q) in transfusion dependence(TD), Lenalidomide is the first choice treatment. However, there are no data regarding natural evolution of anemia in patients diagnosed in MDS and del(5q) without TD, factors that may impact on the development of TD or disease outcome. In the present study we have performed a retrospective multicenter analysis on 83 patients with low-int 1 MDS and del(5q) without TD. During the study 61 patients became TD at a median of 1.7 years and only the Hb level 9 g/dL was associated with poorer TFS (p = 0.007) in the multivariate analysis. Among these 61 TD patients, 49 received treatment (19 Lenalidomide). Median follow up was 48 months, estimated OS at 2 and 5 year was 92% and 50% respectively. In the multivariate analysis for OS, platelets <100,000 mm(-3) and Lenalidomide treatment retained the statistical significant impact. LFS at 2 and 5 years was 86% and 73% respectively, and median time to sAML was 8.16 years (CI 95%: 6.05-10.27). In the multivariate analysis only thrombocytopenia retained statistical significance. In summary, this retrospective study show that level of Hb is an important parameter in order to determine the time until TD, it should be also stressed the importance of an early treatment in order to prevent TD development and shorter survival.

Lenalidomide as a disease-modifying agent in patients with del(5q) myelodysplastic syndromes: linking mechanism of action to clinical outcomes

Deletion of the long arm of chromosome 5, del(5q), is the most prevalent cytogenetic abnormality in patients with myelodysplastic syndromes (MDS). In isolation, it is traditionally associated with favorable prognosis compared with other subtypes of MDS. However, owing to the inherent heterogeneity of the disease, prognosis for patients with del(5q) MDS is highly variable depending on the presence of factors such as additional chromosomal abnormalities, >5 % blasts in the bone marrow (BM), or transfusion dependence. Over recent years, the immunomodulatory drug lenalidomide has demonstrated remarkable efficacy in patients with del(5q) MDS. Advances in the understanding of the pathogenesis of the disease have suggested that lenalidomide targets aberrant signaling pathways caused by haplosufficiency of specific genes in a commonly deleted region on chromosome 5 (e.g., SPARC, RPS14, Cdc25C, and PP2A). As a result, the agent specifically targets del(5q) clones while also promoting erythropoiesis and repopulation of the bone marrow in normal cells. This review discusses recent developments in the understanding of the mechanism of action of lenalidomide, and how this underlies favorable outcomes in patients with del(5q) MDS. In addition, we discuss how improved understanding of the mechanism of disease will facilitate clinicians’ ability to predict/monitor response and identify patients at risk of relapse.

Prognostic impact of JAK2V617F mutation in myelodysplatic syndromes: A matched case control study

While in RARS-T, JAK2V617F mutation is common and associated with good prognosis, the clinical and prognostic impact of this mutation in other MDS is unknown. We collected data from 132 non-RARS-T MDS with known JAK2V617F mutation status. JAK2V617F mutation was significantly correlated with lower progression to AML (p<.0011) and better overall survival (OS, p=.011). OS difference persisted after matching on age, sex, IPSS and % marrow blast (p=.031). Thus, in MDS other than RARS-T, JAK2V617F mutation may be associated with favorable outcome.

Targeted re-sequencing analysis of 25 genes commonly mutated in myeloid disorders in del(5q) myelodysplastic syndromes

Interstitial deletion of chromosome 5q is the most common chromosomal abnormality in myelodysplastic syndromes. The catalogue of genes involved in the molecular pathogenesis of myelodysplastic syndromes is rapidly expanding and next-generation sequencing technology allows detection of these mutations at great depth. Here we describe the design, validation and application of a targeted next-generation sequencing approach to simultaneously screen 25 genes mutated in myeloid malignancies. We used this method alongside single nucleotide polymorphism-array technology to characterize the mutational and cytogenetic profile of 43 cases of early or advanced del(5q) myelodysplastic syndromes. A total of 29 mutations were detected in our cohort. Overall, 45% of early and 66.7% of advanced cases had at least one mutation. Genes with the highest mutation frequency among advanced cases were TP53 and ASXL1 (25% of patients each). These showed a lower mutation frequency in cases of 5q- syndrome (4.5% and 13.6%, respectively), suggesting a role in disease progression in del(5q) myelodysplastic syndromes. Fifty-two percent of mutations identified were in genes involved in epigenetic regulation (ASXL1, TET2, DNMT3A and JAK2). Six mutations had allele frequencies <20%, likely below the detection limit of traditional sequencing methods. Genomic array data showed that cases of advanced del(5q) myelodysplastic syndrome had a complex background of cytogenetic aberrations, often encompassing genes involved in myeloid disorders. Our study is the first to investigate the molecular pathogenesis of early and advanced del(5q) myelodysplastic syndromes using next-generation sequencing technology on a large panel of genes frequently mutated in myeloid malignancies, further illuminating the molecular landscape of del(5q) myelodysplastic syndromes.