Impact of mutational studies on the diagnosis and the outcome of high-risk myelodysplastic syndromes and secondary acute myeloid leukemia patients treated with 5-azacytidine

Outcomes with allogeneic hematopoietic stem cell transplantation in TP53-mutated myelodysplastic syndrome: A systematic review and meta-analysis

We conducted a systematic review and meta-analysis to evaluate outcomes after allogeneic hematopoietic stem cell transplantation (Allo-HSCT) in TP53-mutated myelodysplastic syndromes (MDS). A literature search was performed on PubMed, Cochrane, Embase, and Clinicaltrials.gov. After screening 626 articles, eight studies were included. Data were extracted following the PRISMA guidelines and analyzed using the meta-package by Schwarzer et al. We analyzed 540 patients. The pooled median 3 (1-5) year overall survival was 21% (95% CI 0.08-0.37, I2=91%, n=540). The pooled relapse rate was 58.9% (95% CI 0.38-0.77, I2=93%, n=487) at a median of 1.75 (1-3) years. The pooled 4-year progression- free survival was 34.8% (95% CI 0.15-0.57, I2=72%, n=105). Outcomes of Allo-HSCT for TP53-mutated MDS patients remain poor, with 21% OS at three years; however, Allo-HSCT confers a survival advantage as compared to non-transplant palliative therapies. Our findings suggest the need to explore novel therapeutic agents in prospective clinical trials.

Secondary Acute Myeloid Leukemia in Myelodysplastic Syndrome Patients Aged Over 60 Years

In myelodysplastic syndrome (MDS), neoplastic cells originate in hematopoietic stem cells of the bone marrow, causing dysplasia in multiple cell lines. This may ultimately lead to cytopenia and anemia. MDS generally occurs in patients aged over 60 years, and if left unchecked, it can lead to secondary acute myeloid leukemia (AML), which has a worse prognosis than de novo AML. Hence, it is important to find methods to treat and manage MDS and prevent secondary AML. This review tries to point out the best methods to find out the best possible treatment for MDS, which can lead to its remission or possibly cure and prevent it from progressing into AML. In order to do this, the pathogenesis of MDS is taken into account, and it is clear that the various molecular mutations that lead to the hematologic neoplasms directly affect the different chemotherapy agents that can be used. The different common mutations leading to MDS and secondary AML have been reviewed along with the drugs best inclined to target them. Some mutations lead to a worse prognosis than others, and ongoing mutations can lead to drug-resistant neoplasms. Thus, drugs targeting the mutations need to be used. The feasibility of an allogeneic stem cell transplant is also taken into account, as this can lead to a total cure of MDS. Methods of decreasing post-transplant recovery time and complications have been looked into, and more studies need to be done on the matter. Currently, it is clear that a more personalized approach to each individual case with its own set of drug combinations is the best approach to treating MDS and secondary leukemia and increasing the overall survival (OS).

Identification of a specific immunophenotype associated with a consistent pattern of genetic mutations including SRFS2 and gene expression profile in MDS

BACKGROUND

Myelodysplastic syndromes (MDS) comprise a heterogeneous group of diseases classified by comprehensive diagnostics. Identification of homogeneous subgroups is desirable to understand differences in clinical course and to develop targeted treatment approaches. We identified a specific CD11b/CD16 expression pattern in granulocytes associated with reduced CD45 expression in myeloid progenitor cells (MPC) in MDS cases and assessed its genetic background by whole genome (WGS) and whole transcriptome sequencing (WTS).

METHODS

The cohort consisted of 32 MDS cases with the specific aberrant immunophenotype. Since all these 32 cases were found to be SRSF2 mutated additional 51 SRSF2 mutated MDS cases without this specific immunophenotype were selected as controls. For all cases WGS and WTS were performed.

RESULTS

The immunophenotype newly identified in SRSF2 mutated MDS patients is characterized (1) by a specific maturation pattern, i.e. an increase of CD11b expression without CD16 expression followed by an increase in CD16 expression without further CD11b expression and (2) by only dim CD45 expression of MPC. STAG2 mutations were exclusively found in MDS cases with the specific immunophenotype (17/32, 53% vs. 0%, p < 0.001). Hence, >50% of cases with the specific immunophenotype were characterized by co-mutations in SRSF2 and STAG2. In addition, cluster analysis revealed a specific gene expression profile of such cases.

CONCLUSION

We here for the first time describe a specific immunophenotype which defines MDS cases with SRSF2 mutations and a consistent and specific mutational and gene expression profile. This comprehensive data warrants analysis of further such cases to assess the feasibility of defining a new sub-entity of MDS.

Predictive and prognostic value of gene mutations in myelodysplastic syndrome treated with hypomethylating agents: a meta-analysis

Although the effect of gene mutations on overall response rate (ORR) and overall survival (OS) in myelodysplastic syndrome (MDS) treated with hypomethylating agents (HMAs) has been explored, the effect is still controversial. We performed this meta-analysis to investigate the effect. The pooled odds ratio (OR) and 95% confidence interval (CI) for ORR and the pooled hazard ratio (HR) and 95%CI for OS were chosen to estimate the effect. The pooled OR of TET2 was 0.73 (95%CI: 0.59-0.91, p = 0.005) and the pooled OR of ASXL1 was 1.38 (95%CI: 1.12-1.71, p = 0.003). As for prognosis, the pooled HR of RUNX1 was 1.45 (95%CI: 1.15-1.85, p = 0.002). The pooled HR of TP53 was 2.30 (95%CI: 1.83-2.90, p < 0.001) and the pooled HR of U2AF1 was 1.41 (95%CI: 1.15-1.74, p = 0.001). There was no statistical difference shown in other genes. Therefore, TET2 mutation and ASXL1 wild-type were the predictor of better response to HMAs. Mutations of TP53, RUNX1, and U2AF1 were associated with poor prognosis in MDS.

TP53 in Myelodysplastic Syndromes

Simple Summary

The importance of gene variants in the prognosis of myelodysplastic syndromes (MDSs) has been repeatedly reported in recent years. Especially, TP53 mutations are independently associated with a higher risk category, resistance to conventional therapies, rapid transformation to leukemia, and a poor outcome. In the review, we discuss the features of monoallelic and biallelic TP53 mutations within MDS, the carcinogenic mechanisms, and the predictive value of TP53 variants in current standard treatments including hypomethylating agents, allogeneic hematopoietic stem cell transplantation, and lenalidomide, as well as the latest progress in TP53-targeted therapy strategies in MDS.

Abstract

Myelodysplastic syndromes (MDSs) are heterogeneous for their morphology, clinical characteristics, survival of patients, and evolution to acute myeloid leukemia. Different prognostic scoring systems including the International Prognostic Scoring System (IPSS), the Revised IPSS, the WHO Typed Prognostic Scoring System, and the Lower-Risk Prognostic Scoring System have been introduced for categorizing the highly variable clinical outcomes. However, not considered by current MDS prognosis classification systems, gene variants have been identified for their contribution to the clinical heterogeneity of the disease and their impact on the prognosis. Notably, TP53 mutation is independently associated with a higher risk category, resistance to conventional therapies, rapid transformation to leukemia, and a poor outcome. Herein, we discuss the features of monoallelic and biallelic TP53 mutations within MDS, their corresponding carcinogenic mechanisms, their predictive value in current standard treatments including hypomethylating agents, allogeneic hematopoietic stem cell transplantation, and lenalidomide, together with the latest progress in TP53-targeted therapy strategies, especially MDS clinical trial data.

Clinical Characteristics, Prognosis, and Treatment Strategies of TP53 Mutations in Myelodysplastic Syndromes

TP53 gene mutations are common in myelodysplastic syndromes (MDS). Previous studies have reported their detrimental effects on patient survival. However, current treatment strategies mainly based on hypomethylating agent therapy (HMA) and hematopoietic stem cell transplantation (HSCT) still leave a lot to be desired. And there is also a lack of studies on large sample with a view to the refinement of specific characteristics and disease progression. So we performed a meta-analysis including 20 studies compromising 5067 patients to assess the prognostic impact and clinical characteristics of TP53 mutations in MDS patients. The overall hazard ratio for overall survival (OS) was 2.14 (95% confidence interval 1.94-2.37, P < .00001) compared with patients with MDS without TP53 mutations. Lower progression-free survival and leukemia-free survival were associated with TP53 mutations. Subgroup analysis revealed that TP53 mutations were significantly associated with high levels of blast cells and karyotypic aberrations. And among Asian population, the adverse impact on OS of TP53 mutations seemed worse than those in Western countries. (HR 2.87 vs. 2.02, P = .01). In addition, TP53 mutations had no effect on response to HMA therapy, and HSCT improved OS in patients carrying TP53 mutations.

Co-occurrence of cohesin complex and Ras signaling mutations during progression from myelodysplastic syndromes to secondary acute myeloid leukemia

Myelodysplastic syndromes (MDS) are hematological disorders at high risk of progression to secondary acute myeloid leukemia (sAML). However, the mutational dynamics and clonal evolution underlying disease progression are poorly understood at present. To elucidate the mutational dynamics of pathways and genes occurring during the evolution to sAML, next generation sequencing was performed on 84 serially paired samples of MDS patients who developed sAML (discovery cohort) and 14 paired samples from MDS patients who did not progress to sAML during follow-up (control cohort). Results were validated in an independent series of 388 MDS patients (validation cohort). We used an integrative analysis to identify how mutations, alone or in combination, contribute to leukemic transformation. The study showed that MDS progression to sAML is characterized by greater genomic instability and the presence of several types of mutational dynamics, highlighting increasing (STAG2) and newly-acquired (NRAS and FLT3) mutations. Moreover, we observed cooperation between genes involved in the cohesin and Ras pathways in 15-20% of MDS patients who evolved to sAML, as well as a high proportion of newly acquired or increasing mutations in the chromatin-modifier genes in MDS patients receiving a disease-modifying therapy before their progression to sAML.

Factors affecting response to 5-azacytidine and prognosis of myelodysplastic syndrome. Is long-term survival a realistic goal?

The introduction of hypomethylating agents (HMAs) 5-azacytidine and decitabine has altered the prognosis of patients with myelodysplastic syndrome (MDS). Over the past few years, the International Prognostic Scoring System (IPSS) and the revised IPSS (IPSS-R) have been used both to define the prognosis of patients with MDS and to select patients to be treated with HMAs. Nevertheless, the prognosis of individual patients with MDS can differ considerably from the one calculated with the use of the above-mentioned prognostic systems. Thus, some patients may achieve long-term survival irrespective of their initial prognostic score. Several factors besides those used to define the IPSS/IPSS-R are analyzed in this review article; these include age and gender, the baseline hematologic characteristics, the comorbidities, the cytogenetic and molecular profile of the patients, as well as their response to treatment with 5-azacytidine. Thus, insight into a more personalized way of managing patients with MDS is given and long-term survival is set as a more realistic goal of treatment with 5-azacytidine.

Incorporation of somatic panels for the detection of haematopoietic transformation in children and young adults with leukaemia predisposition syndromes and with acquired cytopenias

Detection of somatic mutations may help verify the diagnosis of myelodysplastic syndrome (MDS) in patients with persistent cytopenias or with MDS-predisposition syndromes, prior to the development of overt leukemia. However, the spectrum and consequences of acquired changes in paediatric patients have not been fully evaluated, and especially not in the context of an underlying syndrome. We incorporated a targeted next-generation-sequencing panel of 54 genes for the detection of somatic mutations in paediatric and young adult patients with inherited or acquired cytopenias. Sixty-five patients were included in this study, of whom 17 (26%) had somatic mutations. We detected somatic mutations in 20% of individuals with inherited MDS-predisposition syndromes, including in patients with severe congenital neutropenia and Fanconi anaemia, and with germline mutations in SAMD9L. Thirty-eight per cent of children with acquired cytopenias and suspected MDS had somatic changes, most commonly in genes related to signal transduction and transcription. Molecularly abnormal clones often preceded cytogenetic changes. Thus, routine performance of somatic panels can establish the diagnosis of MDS and determine the optimal timing of haematopoietic stem cell transplantation, prior to the development of leukaemia. In addition, performing somatic panels in patients with inherited MDS-predisposition syndromes may reveal their unique spectrum of acquired mutations.

Role Of TP53 mutations in predicting the clinical efficacy of hypomethylating therapy in patients with myelodysplastic syndrome and related neoplasms: a systematic review and meta-analysis

Hypomethylating agents (HMAs) are now a major treatment option for myelodysplastic syndrome (MDS) and related neoplasms, but 50% of patients still do not respond and realize poor outcomes. Mutational predictors of treatment efficacy attract continuous attention. Whether TP53 mutations can be used as predictors of HMA effectiveness has caused heated debate. Therefore, we performed a meta-analysis to investigate the predictive value of TP53 mutations to outcomes of HMA therapy in patients with MDS and related neoplasms. We systematically searched PubMed, Embase, the Cochrane Library, and the WanFang databases (published deadline: September 12, 2019). The primary endpoints were overall response rate (ORR) and overall survival (OS). Odds ratio (OR), hazard ratio (HR), and 95% confidence intervals (CI) were pooled to estimate the association between TP53 mutations and the clinical efficacy of HMAs. Four hundred fifteen papers were found, and 22 papers were included in this meta-analysis (N = 2020 participants). The results showed that the presence of TP53 mutation predicted an increased overall response rate with HMA treatment in the subsets that restricted patients in de novo disease, MDS by WHO (World Health Organization) criteria, or NGS (next-generation sequence) group (P = 0.005, P = 0.003, P = 0.0005, respectively). However, TP53 mutations remained poor factors for OS (P < 0.00001). Collectively, in HMA therapy, TP53 mutations can predict better ORR when setting more refined subgroups, but TP53 mutations still strongly correlated with poor survival in hypomethylating therapy.

Comparison of SF3B1/DNMT3A Comutations With DNMT3A or SF3B1 Mutation Alone in Myelodysplastic Syndrome and Clonal Cytopenia of Undetermined Significance

OBJECTIVES

To compare the clinical significance of SF3B1/DNMT3A Comutations with SF3B1 or DNMT3A mutation alone in myelodysplastic syndrome (MDS) and clonal cytopenia of undetermined significance (CCUS).

METHODS

We identified and compared 31 patients with only DNMT3A mutation, 48 patients with only SF3B1 mutation, and 16 patients with only SF3B1/DNMT3A comutations.

RESULTS

SF3B1/DNMT3A comutations were found to be more common in MDS, whereas DNMT3A mutation alone was more common in CCUS. The patients with SF3B1/DNMT3A comutations were less likely to have poor cytogenetics than patients with DNMT3A mutation alone. Patients with SF3B1/DNMT3A comutations showed significantly longer median survival time and better overall survival than patients with DNMT3A mutation alone.

CONCLUSIONS

Patients with SF3B1/DNMT3A comutations appear to have better clinical outcomes than patients with isolated DNMT3A mutation. These findings suggest that the favorable prognosis of SF3B1 mutation in is not abrogated by the concurrent presence of a DNMT3A mutation.

Prognostic value of DNMT3A mutations in myelodysplastic syndromes: a meta-analysis

Objectives: Although DNA (cytosine-5)-methyltransferase 3 alpha (DNMT3A) gene mutations have been widely reported in myelodysplastic syndromes (MDS), the prognostic significance of DNMT3A mutations is still controversial. In this study, we conducted a meta-analysis to determine the prognostic effect of DNMT3A mutations in patients with MDS. Methods: Eligible studies from PubMed, Embase, Web of Science, Clinical Trials and the Cochrane Library were searched. Hazard ratios (HRs) and their 95% confidence intervals (CIs) for overall survival (OS) and leukemia-free survival (LFS) were pooled to assess the effect of DNMT3A mutations on the prognosis in MDS patients. Results: A total of 12 studies with 2236 patients were included in this meta-analysis. The pooled HRs for OS and LFS revealed that MDS patients with DNMT3A mutations had a significantly poor prognosis as compared with those without mutations (OS: HR = 1.654, 95% CI = 1.387-1.973, p < 0.001; LFS: HR = 4.624, 95% CI = 3.121-6.851, p < 0.001). Discussion and Conclusion: This meta-analysis showed an adverse prognostic effect of DNMT3A mutations in patients with MDS, which will contribute to risk stratification and prognostic assessment in the disease.

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.