Mayo Alliance Prognostic Model for Myelodysplastic Syndromes: Integration of Genetic and Clinical Information

Prognostic value of ASXL1 mutations in patients with myelodysplastic syndromes and acute myeloid leukemia: A meta-analysis

Additional sex combs-like 1 (ASXL1) mutations, a hotspot in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), have been frequently reported for their potential prognostic value, but the results are controversial. Therefore, a meta-analysis was performed. Databases, including PubMed, Embase, and Cochrane Library, were searched for relevant studies published up to January 13, 2022. STATA v16.0 software was used to calculate the combined hazard ratios (HRs) and their 95% confidence intervals (CIs) for overall survival (OS) and AML transformation. Subgroup analysis was used to explore the effects of the grouping factors on heterogeneity.Ten studies on ASXL1 mutations and the prognosis of MDS were selected. Our results indicate that ASXL1 mutations have an adverse prognostic impact on OS (HR = 1.68,95%CI:1.45-1.94, p < .0001) and AML transformation (HR = 2.20,95% CI:1.68-2.87, p < .0001). The results for different age groups were not significantly different (HR = 1.87,95% CI: 1.31-2.67; HR = 1.62,95% CI:1.35-2.07). Ten studies covering 5816 patients with AML were included. The pooled HR for OS was 1.37 (95% CI:1.20-1.56, p < .0001). ASXL1 mutations were especially associated with a poorer OS in the subgroup aged ≥60 years (HR = 2.86, 95% CI:1.34-6.08, p = .006); when considering cytogenetically normal AML (CN-AML), the HR was 1.78(95% CI:1.27-2.49, p = .001). This meta-analysis indicates an independent, adverse prognostic impact of ASXL1 mutations in patients with MDS and AML, which also applies to patients with CN-AML. Age was a risk factor for patients with AML and ASXL1 mutations but not for patients with MDS.

Updates on risk stratification and management of lower-risk myelodysplastic syndromes/neoplasms

The majority of lower-risk myelodysplastic syndromes/neoplasms patients present with anemia. Historically, these patients were treated with erythropoiesis-stimulating agents (ESA), with modest responses. A subset of these patients with del(5q) may do better with lenalidomide. Recently, in randomized trials, luspatercept has shown better responses compared with ESAs in treatment-naive patients and imetelstat in patients refractory to ESAs. Other evaluated novel compounds (fostamatinib, H3B-880, roxadustat, pyruvate kinase receptor activator) have not yet shown meaningful efficacy. More needs to be done to improve outcomes; in pursuance of this, participation in clinical trials evaluating novel therapies should be encouraged. While lower-risk myelodysplastic syndromes/neoplasms tend to have an indolent course, a subset of them has a dismal prognosis. Improving prognostication and serial monitoring will help in identifying high-risk patients for appropriate management.

Navigating the contested borders between myelodysplastic syndrome and acute myeloid leukemia

Myelodysplastic syndrome and acute myeloid leukemia are heterogeneous myeloid neoplasms which arise from the accumulation of mutations in a myeloid stem cell or progenitor that confer survival or growth advantages. These disease processes are formally differentiated by clinical, laboratory, and morphological presentations, especially with regard to the preponderance of blasts in the peripheral blood or bone marrow (AML); however, they are closely associated through their shared lineage as well as their existence on a spectrum with some cases of MDS displaying increased blasts, a feature that reflects more AML-like behavior, and the propensity for MDS to transform into AML. It is increasingly recognized that the distinctions between these two entities result from the divergent patterns of genetic alterations that drive each of them. Mutations in genes related to chromatin-remodeling and the spliceosome are seen in both MDS and AML arising out of antecedent MDS, while mutations in genes related to signaling pathways such as RAS or FLT3 are more typically seen in AML or otherwise are a harbinger of transformation. In this review, we focus on the insights into the biological and genetic distinctions and similarities between MDS and AML that are now used to refine clinical prognostication, guide disease management, and to inform development of novel therapeutic approaches.

Past, present and future in low-risk myelodysplastic syndrome

Myelodysplastic syndromes (MDS) is a heterogeneous group of disorders characterized by increased risk of acute myeloid leukemia transformation and cytopenia. The prognosis of MDS patients can be evaluated with various scoring systems, the most commonly used are IPSS (International Prognostic Scoring System), revised-IPSS, and WPSS (WHO classification-based prognostic scoring system). MDS treatment is decided according to the risk classification. The goal of treatment in low-risk MDS is to improve cytopenia, reduce transfusion needs, improve quality of life, prolong overall survival, and maybe reduce the risk of progression to leukemia. In the near future, combining both genomics-based, ex vivo functional based and molecular stratification analysis will lead the way to a personalized and targeted approach.

The spectrum of genetic mutations in myelodysplastic syndrome: Should we update prognostication?

The natural history of patients with myelodysplastic syndrome (MDS) is dependent upon the presence and magnitude of diverse genetic and molecular aberrations. The International Prognostic Scoring System (IPSS) and revised IPSS (IPSS-R) are the most widely used classification and prognostic systems; however, somatic mutations are not currently incorporated into these systems, despite evidence of their independent impact on prognosis. Our manuscript reviews prognostic information for TP53, EZH2, DNMT3A, ASXL1, RUNX1, SRSF2, CBL, IDH 1/2, TET2, BCOR, ETV6, GATA2, U2AF1, ZRSR2, RAS, STAG2, and SF3B1. Mutations in TP53, EZH2, ASXL1, DNMT3A, RUNX1, SRSF2, and CBL have extensive evidence for their negative impact on survival, whereas SF3B1 is the lone mutation carrying a favorable prognosis. We use the existing literature to propose the incorporation of somatic mutations into the IPSS-R. More data are needed to define the broad spectrum of other genetic lesions, as well as the impact of variant allele frequencies, class of mutation, and impact of multiple interactive genomic lesions. We postulate that the incorporation of these data into MDS prognostication systems will not only enhance our therapeutic decision making but lead to targeted treatment in an attempt to improve outcomes in this formidable disease.

How low risk are low risk myelodysplastic syndromes?

INTRODUCTION

Risk stratification is crucial to the appropriate management of many diseases, but in patients with myelodysplastic syndromes (MDS), for whom expected survival can vary greatly, accurate disease prognostication is especially important. This is further supported by a relative lack of therapies in MDS, and thus we must prognosticate carefully and accurately. Currently, patients with MDS are often grouped into higher-risk (HR) versus lower-risk (LR) disease using clinical prognostic scoring systems, but these systems have limitations.

AREAS COVERED

The authors reviewed the literature on diagnostics, prognostics, therapeutics and outcomes in MDS. Factors such as disease etiology, specific clinical characteristics, or molecular genetic information not captured in the international prognostic scoring system revised IPSS-R can alter risk stratification, and identify a subset of LR-MDS patients who actually behave more like HR-MDS.

EXPERT OPINION

This review will describe the current identification and management of patients with LR MDS disease whose condition is likely to behave in a less favorable manner than predicted by the IPSS-R. The authors comment on clinical and molecular features which are believe to upstage a patient from lower to higher risk disease.

Evidence-Based Minireview: Molecular precision and clinical uncertainty: should molecular profiling be routinely used to guide risk stratification in MDS?

This is a focused clinical vignette and review of the literature in MDS to discuss the application of molecular sequencing for risk stratification in MDS. The authors utilize an exemplar patient case and explain the advantages and disadvantages, based on available data, of routine use of this testing for MDS patients.

Myelodysplastic syndromes with ring sideroblasts (MDS-RS) and MDS/myeloproliferative neoplasm with RS and thrombocytosis (MDS/MPN-RS-T) - "2021 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 myelodysplastic syndromes with RS (MDS-RS) and MDS/myeloproliferative neoplasm with RS and thrombocytosis (MDS/MPN-RS-T).

DIAGNOSIS

MDS-RS is a lower risk MDS, with single or multilineage dysplasia (MDS-RS-SLD/MLD), <5% bone marrow (BM) blasts, <1% peripheral blood 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 × 10⁹ /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 (50%), DNMT3A, TET2 and ASXL1 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 (MPN). Both diseases are associated with 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. Luspatercept, a first-in-class erythroid maturation agent is now approved for the management of anemia in patients with MDS-RS and MDS/MPN-RS-T. Aspirin therapy is reasonable in MDS/MPN-RS-T, especially in the presence of JAK2V617F, but the value of platelet-lowering drugs remains to be defined.

The expression levels of long non-coding RNA KIAA0125 are associated with distinct clinical and biological features in myelodysplastic syndromes

Long non-coding RNAs (lncRNAs) have important functions in cancer biology. Among them, lncRNA KIAA0125 is one of the genes proposed to play a critical role in leukaemia stem cell (LSC). In this study, we aimed to investigate the clinical relevance of the expression levels of lncRNA KIAA0125 in myelodysplastic syndromes (MDS), a disease with highly heterogeneous clinical and biological features. Using RNA arrays, we measured the expression of KIAA0125 in 176 primary MDS patients. We found that higher KIAA0125 expression was associated with higher risk MDS, based on the revised International Prognostic Scoring System (IPSS-R), mutations in ASXL1 and NRAS, and predicted poorer overall survival (OS) and leukaemia-free survival (LFS). Multivariate analysis revealed that higher KIAA0125 expression was an independent, unfavourable prognostic factor for OS and LFS, irrespective of IPSS-R and mutation status. Further global gene expression profile analysis suggested a close association of higher KIAA0125 expressions with LSC signatures. The expression of KIAA0125 may be a potential biomarker to guide the treatment choice in MDS patients, especially those with lower risk subtypes, in whom palliative treatment is usually used.

Myelodysplastic syndromes: moving towards personalized management

The myelodysplastic syndromes (MDS) share their origin in the hematopoietic stem cell but have otherwise very heterogeneous biological and genetic characteristics. Clinical features are dominated by cytopenia and a substantial risk for progression to acute myeloid leukemia. According to the World Health Organization, MDS is defined by cytopenia, bone marrow dysplasia and certain karyotypic abnormalities. The understanding of disease pathogenesis has undergone major development with the implementation of next-generation sequencing and a closer integration of morphology, cytogenetics and molecular genetics is currently paving the way for improved classification and prognostication. True precision medicine is still in the future for MDS and the development of novel therapeutic compounds with a propensity to markedly change patients' outcome lags behind that for many other blood cancers. Treatment of higher-risk MDS is dominated by monotherapy with hypomethylating agents but novel combinations are currently being evaluated in clinical trials. Agents that stimulate erythropoiesis continue to be first-line treatment for the anemia of lower-risk MDS but luspatercept has shown promise as second-line therapy for sideroblastic MDS and lenalidomide is an established second-line treatment for del(5q) lower-risk MDS. The only potentially curative option for MDS is hematopoietic stem cell transplantation, until recently associated with a relatively high risk of transplant-related mortality and relapse. However, recent studies show increased cure rates due to better tools to target the malignant clone with less toxicity. This review provides a comprehensive overview of the current status of the clinical evaluation, biology and therapeutic interventions for this spectrum of disorders.

Cui bono? Finding the value of allogeneic stem cell transplantation for lower-risk myelodysplastic syndromes

Introduction: The myelodysplastic syndromes (MDS) vary in their risk of disease progression; progression includes increasingly severe bone marrow failure, reclassification as acute myeloid leukemia (AML), and death. Prognostic tools guide recommendations for allogeneic stem cell transplantation (alloSCT), the only curative option. AlloSCT is typically reserved for patients with higher-risk MDS as defined by existing prognostic tools, although additional clinical and biological factors in lower-risk patients may influence this dogma.Areas covered: This review discusses the current understanding of MDS risk stratification as it pertains to the use of alloSCT in subpopulations of MDS patients with a particular focus on the use of alloSCT in patients with lower-risk disease.Expert commentary: Though high-quality data are lacking, some lower-risk MDS patients may benefit from alloSCT, which offers the only prospect of cure. Understanding the etiologic role and prognostic impact of recurring genetic events may improve existing risk stratification and become integral facets of prognostic schemata. The identification of additional factors influencing the prognoses of patients currently lumped together as 'lower-risk' will likewise improve the selection of MDS patients for early intervention or aggressive therapies such as alloSCT.

Outcomes after venous thromboembolism in patients with gastric cancer: Analysis of the RIETE Registry

Gastric cancer is the fifth most common malignancy worldwide. Venous thromboembolism is an independent predictor of death among patients with gastric cancer. We aimed to describe the factors associated with mortality, thrombosis recurrence, and bleeding complications in patients with gastric cancer who develop venous thromboembolism. We included 612 patients with gastric cancer and venous thromboembolism in the Registro Informatizado de la Enfermedad TromboEmbólica (RIETE) registry from 2001 to 2018. We used Cox proportional hazard ratios and a Fine-Gray model to define factors associated with outcomes. The overall mortality at 6 months was 44.4%. Factors associated with increased 6-month mortality included immobility (HR 1.8, 95% CI 1.3-2.4; p < 0.001), anemia (HR 1.4, 95% CI 1.1-1.8; p < 0.02), and leukocytosis (HR 1.8, 95% CI 1.4-2.3; p < 0.001). Recurrent thrombosis occurred in 6.5% of patients and major bleeding complications in 8.5% of the cohort. Male sex was the main factor associated with thrombosis recurrence (HR 2.1, 95% CI 1.1-4.0; p < 0.02) and hemoglobin below 10 g/dL (HR 1.6, 95% CI 1.05-2.50; p = 0.03) the main factor associated with bleeding. In conclusion, patients with gastric cancer who develop venous thrombosis have a very high likelihood of death. Low hemoglobin in this population is associated with poor outcomes.

Mutation-enhanced international prognostic systems for essential thrombocythaemia and polycythaemia vera

Survival prediction in essential thrombocythaemia (ET) and polycythaemia vera (PV) is currently based on clinically-derived variables; we examined the possibility of integrating genetic information for predicting survival. To this end, 906 molecularly-annotated patients (416 Mayo Clinic; 490 University of Florence, Italy), including 502 ET and 404 PV, were recruited. Multivariable analysis identified spliceosome mutations to adversely affect overall (SF3B1, SRSF2 in ET and SRSF2 in PV) and myelofibrosis-free (U2AF1, SF3B1 in ET) survival; TP53 mutations predicted leukaemic transformation in ET; "adverse" mutations occurred in 51 (10%) ET and 8 (2%) PV patients. We confirmed the independent survival effect of adverse mutations [hazard ratio (HR) 2·4, 95% CI 1·6-3·5], age >60 years (6·6, 4·6-9·7), male sex (1·8, 1·3-2·4) and leukocytosis ≥11 × 10⁹ /l (1·6, 1·1-2·2), in ET, and adverse mutations (7·8, 3·1-17·0), age >67 years (5·4, 3·6-8·1), leukocytosis ≥15 × 10⁹ /l (2·8, 1·8-4·2) and thrombosis history (2·0, 1·4-2·9), in PV. HR-based risk point allocation allowed development of three-tiered mutation-enhanced international prognostic systems (MIPSS) which were validated in both cohorts and performance was shown to be superior to conventional scoring systems. Spliceosome mutations enhance survival prediction in ET and PV and identify patients at risk for fibrotic progression. TP53 mutations predict leukaemic transformation in ET.

Treatment of myelodysplastic syndrome in the era of next-generation sequencing

Next-generation sequencing (NGS) is rapidly changing the clinical care of patients with myelodysplastic syndrome (MDS). NGS can be used for various applications: (i) in the diagnostic process to discriminate between MDS and other diseases such as aplastic anaemia, myeloproliferative disorders and idiopathic cytopenias; (ii) for classification, for example, where the presence of SF3B1 mutation is one criterion for the ring sideroblast anaemia subgroups in the World Health Organization 2016 classification; (iii) for identification of patients suitable for targeted therapy (e.g. IDH1/2 inhibitors); (iv) for prognostication, for example, where specific mutations (e.g. TP53 and RUNX1) are associated with inferior prognosis, whereas others (e.g. SF3B1) are associated with superior prognosis; and (v) to monitor patients for progression or treatment failure. Most commonly, targeted sequencing for genes (normally 50-100 genes) reported to be recurrently mutated in myeloid disease is used. At present, NGS is rarely incorporated into clinical guidelines although an increasing number of studies have demonstrated the benefit of using NGS in the clinical management of MDS patients.

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.

Mutations and karyotype predict treatment response in myelodysplastic syndromes

We examined the influence of mutations and karyotype on conventional treatment response, specifically hematological improvement in anemia, in primary myelodysplastic syndromes (MDS). Cytogenetic and next generation sequencing (NGS)-derived mutation information was available in 357 patients (median age 74 years; 70% males); the revised international prognostic scoring system risk distribution was very high in 11%, high 15%, intermediate 17%, low 40% and very low 16%. At least one mutation was detected in 81% of patients; most frequent were SF3B1 (32%), ASXL1 (27%), TET2 (24%) and U2AF1 (15%). At median follow-up of 24 months, treatment with hypomethylating agents (HMAs) was documented in 121 (34%) patients, lenalidomide (LEN) in 55 (15%), and erythropoiesis stimulating agents (ESAs) in 136 (38%). ASXL1 mutations adversely affected response to HMAs (27% vs 48%; P = 0.02) and LEN (9% vs 43%; P = 0.04), but not ESAs (P = 0.6). LEN response was also adversely affected by U2AF1 mutations (0% vs 42%; P = 0.02) and high risk karyotype (0% vs 41% in intermediate vs 47% in low risk; P = 0.01). Patients with SF3B1 mutations were more likely to respond to LEN (56% vs 27%; P = 0.04). Contrary to previous reports, we found no association between TET2 mutations and HMA treatment response (40% vs 41%; P = 0.9), even in the absence of ASXL1 mutations (P = 0.4).We conclude that ASXL1 mutations in MDS predict inferior response to treatment with both HMAs and LEN; response to LEN was also compromised by U2AF1 mutations and high risk karyotype; SF3B1 mutations identified patients likely to respond to LEN.

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

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