Project description:The myelodysplastic syndromes are a diverse group of clonal stem cell disorders characterized by ineffective hematopoiesis, peripheral cytopenias, and an increased propensity to evolve to acute myeloid leukemia. The molecular pathogenesis of these disorders is poorly understood, but recurring chromosomal abnormalities occur in approximately 50% of cases and are the focus of much investigation. The availability of newer molecular techniques has allowed the identification of additional genetic aberrations, including mutations and epigenetic changes of prognostic and potential therapeutic importance. This review focuses on the key role of cytogenetic analysis in myelodysplastic syndromes in the context of the diagnosis, prognosis, and pathogenesis of these disorders.
Project description:Alterations in DNA methylation have been implicated in the pathogenesis of myelodysplastic syndromes (MDS), although the underlying mechanism remains largely unknown. Methylation of CpG dinucleotides is mediated by DNA methyltransferases, including DNMT1, DNMT3A and DNMT3B. DNMT3A mutations have recently been reported in patients with de novo acute myeloid leukemia (AML), providing a rationale for examining the status of DNMT3A in MDS samples. In this study, we report the frequency of DNMT3A mutations in patients with de novo MDS, and their association with secondary AML. We sequenced all coding exons of DNMT3A using DNA from bone marrow and paired normal cells from 150 patients with MDS and identified 13 heterozygous mutations with predicted translational consequences in 12/150 patients (8.0%). Amino acid R882, located in the methyltransferase domain of DNMT3A, was the most common mutation site, accounting for 4/13 mutations. DNMT3A mutations were expressed in the majority of cells in all tested mutant samples regardless of myeloblast counts, suggesting that DNMT3A mutations occur early in the course of MDS. Patients with DNMT3A mutations had worse overall survival compared with patients without DNMT3A mutations (P=0.005) and more rapid progression to AML (P=0.007), suggesting that DNMT3A mutation status may have prognostic value in de novo MDS.
Project description:Myelodysplastic syndromes (MDS) are a heterogeneous group of hematopoietic stem cell disorders characterized by ineffective hematopoiesis with abnormal blood cell development (dysplasia) leading to cytopenias and an increased risk for progression to acute myeloid leukemia (AML). Patients with MDS can generally be classified as lower- (LR-MDS) or higher-risk (HR-MDS). As treatment goals for patients with LR-MDS and those with HR-MDS differ significantly, appropriate diagnosis, classification, and follow-up are critical for correct disease management. In this review, we focus on the diagnosis, prognosis, and treatment options, as well as the prediction of the disease course and monitoring of treatment response in patients with LR-MDS. We discuss how next-generation sequencing, increasing knowledge on mechanisms of MDS pathogenesis, and novel therapies may change the current treatment landscape in LR-MDS and why structured assessments of responses, toxicities, and patient-reported outcomes should be incorporated into routine clinical practice.
Project description:Control of oxidative stress in the bone marrow (BM) is key for maintaining the balance between self-renewal, proliferation, and differentiation of hematopoietic cells. Breakdown of this regulation can lead to diseases characterized by BM failure such as the myelodysplastic syndromes (MDS). To better understand the role of oxidative stress in MDS development, we compared protein carbonylation as an oxidative stress marker in BM of patients with MDS and control subjects, and also patients with MDS under treatment with the iron chelator deferasirox.
Project description:High-throughput DNA sequencing significantly contributed to diagnosis and prognostication in patients with myelodysplastic syndromes (MDS). We determined the biological and prognostic significance of genetic aberrations in MDS. In total, 944 patients with various MDS subtypes were screened for known/putative mutations/deletions in 104 genes using targeted deep sequencing and array-based genomic hybridization. In total, 845/944 patients (89.5%) harbored at least one mutation (median, 3 per patient; range, 0-12). Forty-seven genes were significantly mutated with TET2, SF3B1, ASXL1, SRSF2, DNMT3A, and RUNX1 mutated in >10% of cases. Many mutations were associated with higher risk groups and/or blast elevation. Survival was investigated in 875 patients. By univariate analysis, 25/48 genes (resulting from 47 genes tested significantly plus PRPF8) affected survival (P<0.05). The status of 14 genes combined with conventional factors revealed a novel prognostic model ('Model-1') separating patients into four risk groups ('low', 'intermediate', 'high', 'very high risk') with 3-year survival of 95.2, 69.3, 32.8, and 5.3% (P<0.001). Subsequently, a 'gene-only model' ('Model-2') was constructed based on 14 genes also yielding four significant risk groups (P<0.001). Both models were reproducible in the validation cohort (n=175 patients; P<0.001 each). Thus, large-scale genetic and molecular profiling of multiple target genes is invaluable for subclassification and prognostication in MDS patients.
Project description:Myelodysplastic syndromes (MDS) comprise a group of bone marrow diseases characterized by profound heterogeneity in morphologic presentation, clinical course, and cytogenetic features. Roughly 50% of patients display clonal chromosome abnormalities. In several multicentric studies, the karyotype turned out to be one of the most important prognostic parameters and was incorporated into statistical models aiming for a better prediction of the individual prognosis like the International Prognostic Scoring System. However, due to the profound cytogenetic heterogeneity, the impact of many rare abnormalities as well as combinations of anomalies occurring in a substantial portion of patients with MDS is still unknown and can only be delineated on the basis of large international multicentric cooperations. Recently, the German-Austrian MDS Study Group presented cytogenetic findings in 2,072 patients with MDS, which serve as a basis for the characterization of the cytogenetic subgroups discussed in this article. The availability of new therapeutic options for low- and high-risk MDS targeted against distinct entities characterized by specific chromosome abnormalities, like 5q-deletions, monosomy 7, and complex abnormalities underlines the important role of cytogenetics for the clinical management of MDS. This article thus focuses on the clinical and prognostic relevance, the molecular background, and therapeutic perspectives in these three cytogenetic subgroups.
Project description:Although hypomethylating agents (HMAs) significantly improve outcomes in myelodysplastic syndromes (MDS), only half the patients achieve objective responses, and most responders lose response within 1-2 years. Azacitidine prolongs survival by a median of only 9.5 months. Failure of HMA therapy is associated with a very dismal prognosis. Therefore, novel therapeutic approaches are clearly needed.The sequential use of the alternative HMA after failure of first line HMA is associated with modest efficacy. The improved understanding of the biologic underpinnings of the disease have opened the door to study investigational agents that target disrupted molecular pathways critical to the pathogenesis of MDS. Combination treatment strategies using an azacitidine backbone are demonstrating promising early results. Expanding the applicability of allogeneic stem cell transplantation (alloSCT), the only curative modality, by reducing toxicity and relapse rates is another area of active research.Sequential switching to the alternative HMA, clinical trials of novel targeted therapies, azacitidine-based combination therapeutic strategies, and improvements in the alloSCT platform are the main directions in improving outcomes of MDS post HMA failure.
Project description:Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematopoeitic disorders characterized by ineffective hematopoiesis and potential transformation to acute myeloid leukemia (AML). For decades, the mainstay of treatment for MDS was supportive care, including transfusion of blood products and growth factors. Further understanding of disease biology led to the discovery of a high prevalence of hypermethylation of tumor suppressor genes in high-risk MDS and secondary leukemias. Hence, the role of irreversible DNA methlytransferase inhibitors such as azacitidine was investigated with promising outcomes in the treatment of MDS. Azacitidine was initially approved in the USA by the Food and Drug Administration (FDA) in 2004 for the treatment of all subtypes of MDS and was granted expanded approval in 2009 to reflect new overall survival data demonstrated in the AZA-001 study of patients with higher-risk MDS. Azacitidine has demonstrated significant and clinically meaningful prolongation of survival in higher-risk patients with MDS and has changed the natural history of these disorders. The agent maintains a relatively safe toxicity profile, even in older patients. The role of azacitidine has been explored in the treatment of AML and chronic myelomonocytic leukemia and has also been studied in the peritransplant setting. Azacitidine has been combined with other novel agents such as lenalidomide, histone deacetylase inhibitors and growth factors in the hope of achieving improved outcomes. Currently, both intravenous and subcutaneous forms of azacitidine are approved for use in the USA with the oral form being granted fast track status by the FDA.
Project description:Myelodysplastic syndromes (MDSs) represent a heterogeneous group of hematological stem cell disorders with an increasing burden on health care systems. Evidence-based MDS guidelines and recommendations (G/Rs) are published but do not necessarily translate into better quality of care if adherence is not maintained in daily clinical practice. Guideline-based indicators (GBIs) are measurable elements for the standardized assessment of quality of care and, thus far, have not been developed for adult MDS patients. To this end, we screened relevant G/Rs published between 1999 and 2018 and aggregated all available information as candidate GBIs into a formalized handbook as the basis for the subsequent consensus rating procedure. An international multidisciplinary expert panel group (EPG) of acknowledged MDS experts (n = 17), health professionals (n = 7), and patient advocates (n = 5) was appointed. The EPG feedback rates for the first and second round were 82% (23 of 28) and 96% (26 of 27), respectively. A final set of 29 GBIs for the 3 domains of diagnosis (n = 14), therapy (n = 8), and provider/infrastructural characteristics (n = 7) achieved the predefined agreement score for selection (>70%). We identified shortcomings in standardization of patient-reported outcomes, toxicity, and geriatric assessments that need to be optimized in the future. Our GBIs represent the first comprehensive consensus on measurable elements addressing best practice performance, outcomes, and structural resources. They can be used as a standardized instrument with the goal of assessing, comparing, and fostering good quality of care within clinical development cycles in the daily care of adult MDS patients.
Project description:Myelodysplastic syndromes are associated with a risk of severe infections. While neutropenia is likely to be the main predisposing factor, several other immune defects have been reported, including impaired neutrophil function, B-, T- and NK-cell defects and the possible consequences of iron overload due to red blood cell transfusions. The advanced age of most patients, their frequent comorbidities, and the fact that drugs such as hypomethylating agents and lenalidomide, which are effective in myelodysplastic syndromes but can transiently worsen neutropenia, may increase the risk of infection and their severity in this context. The majority of infections in myelodysplastic syndromes are bacterial, while the incidence of fungal infections is not well known and viral infections seem to be rare. No prophylactic measures against infections have demonstrated efficacy in myelodysplastic syndromes. However, pending more data, we propose here some recommendations for the management of patients with myelodysplastic syndromes. In the future, an important contribution can be made by prospective trials testing the efficacy of prophylactic and therapeutic approaches to infection in these patients, especially in the context of the new drugs available for myelodysplastic syndromes.