Comparison and Implications of Mutational Profiles of Myelodysplastic Syndromes, Myeloproliferative Neoplasms, and Myelodysplastic/Myeloproliferative Neoplasms: A Meta-Analysis

BRAF Mutations in Patients with Myeloid Neoplasms: A Cancer Center Multigene Next-Generation Sequencing Analysis Experience

BRAF mutations are rare in myeloid neoplasms and are reported to be associated with poor treatment outcomes. The purpose of our study is to characterize BRAF mutations in myeloid neoplasms using a next-generation sequencing (NGS) panel based on the experiences of a single cancer center. We conducted a retrospective review of patients with myeloid neoplasms who underwent the HopeSeq studies between January 2018 and September 2023. A total of 14 patients with myeloid neoplasms carrying BRAF mutations were included in our cohort. The clinical, pathological, and molecular features of these patients were investigated. Our study indicates that BRAF mutations are rare in myeloid neoplasms, constituting only 0.53% (14/2632) of all myeloid neoplasm cases, with the most common BRAF mutation being BRAF V600E (4/14; 28.6%). Interestingly, we observed that six out of seven patients with acute myeloid leukemia (AML) exhibited AML with monocytic differentiation, and all the patients with AML exhibited an extremely poor prognosis compared to those without BRAF mutations. TET2 (5/14; 35.7%), ASXL1 (4/14; 28.6%), and JAK2 (4/14; 28.6%) were the three most frequently co-mutated genes in these patients. Moreover, we noted concurrent KMT2A gene rearrangement with BRAF mutations in three patients with AML (3/7; 42.9%). Our study suggests that although BRAF mutations are rare in myeloid neoplasms, they play a crucial role in the pathogenesis of specific AML subtypes. Furthermore, RAS pathway alterations, including BRAF mutations, are associated with KMT2A gene rearrangement in AML. However, these findings warrant further validation in larger studies.

Analytical Validation of a 37-Gene Next-Generation Sequencing Panel for Myeloid Malignancies and Review of Initial Findings Incorporating Updated 2022 Diagnostic and Prognostic Guidelines

Myeloid neoplasms are clonal disorders that arise via acquisition of genetic mutations leading to excessive proliferation and defective differentiation. Mutational profiling is vital as it has implications for diagnosis, prognosis, and therapeutic decision-making. Next-generation sequencing (NGS) has become a mainstay in the evaluation of myeloid malignancies, as it enables efficient characterization of multiple genetic changes. Herein, the analytical validation of the 37-gene Archer VariantPlex Core Myeloid panel is reported, using 58 DNA specimens with 87 single-nucleotide variants and 23 insertions/deletions. The panel achieved good depth of coverage, 100% analytical sensitivity and specificity for single-nucleotide variants and insertions/deletions ≤21 bp, and 100% reproducibility, with a reportable limit of detection determined as 5%. The Archer NGS panel can accurately and reproducibly detect variants of clinical significance in myeloid neoplasms. A retrospective analysis of 535 clinical specimens tested with the Archer NGS panel showed a frequency and pattern of mutations across myeloid malignancies that were similar to other published studies. A review of the diagnostic classification of patients with acute myeloid leukemia and myelodysplastic syndrome using the World Health Organization 2017/2022 and International Consensus Classification 2022 guidelines, in addition to European LeukemiaNet 2017/2022 risk stratification of patients with acute myeloid leukemia, was also performed to assess the utility of the molecular information provided by the Archer NGS panel.

Medicinal chemistry perspective of JAK inhibitors: synthesis, biological profile, selectivity, and structure activity relationship

JAK-STAT signalling pathway was discovered more than quarter century ago. The JAK-STAT pathway protein is considered as one of the crucial hubs for cytokine secretion which mediates activation of different inflammatory, cellular responses and hence involved in different etiological factors. The various etiological factors involved are haematopoiesis, immune fitness, tissue repair, inflammation, apoptosis, and adipogenesis. The presence of the active mutation V617K plays a significant role in the progression of the JAK-STAT pathway-related disease. Consequently, targeting the JAK-STAT pathway could be a promising therapeutic approach for addressing a range of causative factors. In this current review, we provided a comprehensive discussion for the in-detail study of anatomy and physiology of the JAK-STAT pathway which contributes structural domain rearrangement, activation, and negative regulation associated with the downstream signaling pathway, relationship between different cytokines and diseases. This review also discussed the recent development of clinical trial entities. Additionally, this review also provides updates on FDA-approved drugs. In the current investigation, we have classified recently developed small molecule inhibitors of JAK-STAT pathway according to different chemical classes and we emphasized their synthetic routes, biological evaluation, selectivity, and structure-activity relationship.

Myeloproliferative Neoplasms: Contemporary Review and Molecular Landscape

Myelofibrosis (MF), Myeloproliferative neoplasms (MPNs), and MDS/MPN overlap syndromes have a broad range of clinical presentations and molecular abnormalities, making their diagnosis and classification complex. This paper reviews molecular aberration, epigenetic modifications, chromosomal anomalies, and their interactions with cellular and other immune mechanisms in the manifestations of these disease spectra, clinical features, classification, and treatment modalities. The advent of new-generation sequencing has broadened the understanding of the genetic factors involved. However, while great strides have been made in the pharmacological treatment of these diseases, treatment of advanced disease remains hematopoietic stem cell transplant.

Exploring the Molecular Landscape of Myelofibrosis, with a Focus on Ras and Mitogen-Activated Protein (MAP) Kinase Signaling

Myelofibrosis (MF) is a clonal myeloproliferative neoplasm (MPN) characterized clinically by cytopenias, fatigue, and splenomegaly stemming from extramedullary hematopoiesis. MF commonly arises from mutations in JAK2, MPL, and CALR, which manifests as hyperactive Jak/Stat signaling. Triple-negative MF is diagnosed in the absence of JAK2, MPL, and CALR but when clinical, morphologic criteria are met and other mutation(s) is/are present, including ASXL1, EZH2, and SRSF2. While the clinical and classic molecular features of MF are well-established, emerging evidence indicates that additional mutations, specifically within the Ras/MAP Kinase signaling pathway, are present and may play important role in disease pathogenesis and treatment response. KRAS and NRAS mutations alone are reportedly present in up to 15 and 14% of patients with MF (respectively), and other mutations predicted to activate Ras signaling, such as CBL, NF1, BRAF, and PTPN11, collectively exist in as much as 21% of patients. Investigations into the prevalence of RAS and related pathway mutations in MF and the mechanisms by which they contribute to its pathogenesis are critical in better understanding this condition and ultimately in the identification of novel therapeutic targets.

Myelodysplastic Syndromes/Myeloproliferative Overlap Neoplasms and Differential Diagnosis in the WHO and ICC 2022 Era: A Focused Review

The myelodysplastic syndromes/myeloproliferative neoplasms (MDS/MPN) category comprises a varied group of myeloid neoplastic diseases characterized by clinical and pathologic overlapping features of both myelodysplastic and myeloproliferative neoplasms. For these reasons, these tumors are challenging in terms of diagnosis. The recent World Health Organization (WHO) 2022 classification and the International Consensus Classification (ICC) made changes in the classification of MDS/MPN compared to the previous 2016 WHO classification and improved the diagnostic criteria of these entities. The aim of this review is to describe the main entities reported in the more recent classifications, focusing on chronic myelomonocytic leukemia (CMML), MDS/MPN with neutrophilia (or atypical CML [aCML]), and MDS/MPN with SF3B1 mutation and thrombocytosis/MDS/MPN with ring sideroblasts and thrombocytosis. A particular emphasis is given to the differential diagnosis and analysis of subtle divergences and semantic differences between the WHO classification and the ICC for these entities.

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.

Disease and Clinical Characteristics of Patients With a Clinical Diagnosis of Myelofibrosis Enrolled in the MOST Study

BACKGROUND

Clinical characteristics and treatment patterns of patients with lower-risk myelofibrosis (MF) are not well described. This analysis from the MOST (NCT02953704) assessed the demographic and clinical characteristics and treatment patterns of patients with the clinical diagnosis of lower-risk MF at enrollment.

PATIENTS AND METHODS

MOST is an ongoing, prospective, observational study in patients with clinical diagnoses of MF or essential thrombocythemia enrolled at clinical practices throughout the United States. Patients included in the MF cohort (≥18 years of age) had low-risk MF by the Dynamic International Prognostic Scoring System or intermediate-1 (INT-1) risk MF (by age >65 years only) at enrollment. Patient data were entered into an electronic case report form during usual-care visits over a planned 36 month observation period.

RESULTS

Two hundred five patients were eligible for this analysis (low risk, n = 85; INT-1 risk, n = 120; median age, 68 years [range, 35-88]); 166 patients (81.0%) had mutation testing results available. The median time from MF diagnosis to enrollment was 1.8 years. Hemoglobin and hematocrit levels were below the normal range in 50.5% and 48.7% of patients, respectively. Nearly all (98.0%) patients had comorbid conditions, most commonly hypertension (49.8%). Fatigue was the most common physician-reported MF symptom (30.7%). At enrollment, 55.6% of patients were receiving MF-directed monotherapy, most frequently hydroxyurea (46.5%) or ruxolitinib (40.4%).

CONCLUSION

Future longitudinal analyses of data from MOST will help identify unmet needs and characterize how patients with lower-risk MF are managed throughout the disease course.

ASXL1 and STAG2 are common mutations in GATA2 deficiency patients with bone marrow disease and myelodysplastic syndrome

Patients with GATA2 deficiencyharbor de novo or inherited germline mutations in the GATA2 transcription factor gene, predisposing them to myeloid malignancies. There is considerable variation in disease progression, even among family members with the same mutation in GATA2. We investigated somatic mutations in 106 patients with GATA2 deficiency to identify acquired mutations that are associated with myeloid malignancies. Myelodysplastic syndrome (MDS) was the most common diagnosis (∼44%), followed by GATA2 bone marrow immunodeficiency disorder (G2BMID; ∼37%). Thirteen percent of the cohort had GATA2 mutations but displayed no disease manifestations. There were no correlations between age or sex with disease progression or survival. Cytogenetic analyses showed a high incidence of abnormalities (∼43%), notably trisomy 8 (∼23%) and monosomy 7 (∼12%), but the changes did not correlate with lower survival. Somatic mutations in ASXL1 and STAG2 were detected in ∼25% of patients, although the mutations were rarely concomitant. Mutations in DNMT3A were found in ∼10% of patients. These somatic mutations were found similarly in G2BMID and MDS, suggesting clonal hematopoiesis in early stages of disease, before the onset of MDS. ASXL1 mutations conferred a lower survival probability and were more prevalent in female patients. STAG2 mutations also conferred a lower survival probability, but did not show a statistically significant sex bias. There was a conspicuous absence of many commonly mutated genes associated with myeloid malignancies, including TET2, IDH1/2, and the splicing factor genes. Notably, somatic mutations in chromatin-related genes and cohesin genes characterized disease progression in GATA2 deficiency.

MDS/MPN-Unclassifiable with t(X;17)(q28;q21) and KANSL1-MTCP1/CMC4 Fusion Gene

Myelodysplastic/myeloproliferative neoplasm, unclassifiable (MDS/MPN-U) is a poorly characterized entity among overlap myeloid syndromes. Recent studies have shown heterogeneous mutational profiles in this group being able to subclassify them into entities closely related to the more well-established disorders under the umbrella term of the MDS/MPN group. Recurrent cytogenetic alterations are, nonetheless, rare in MDS/MPN-U. Here, for the first time, we report a case of MDS/MPN-U with a t(X;17)(q28;q21) chromosomal rearrangement leading to the KANSL1-MTCP1 fusion gene.

The JAK-STAT pathway: an emerging target for cardiovascular disease in rheumatoid arthritis and myeloproliferative neoplasms

Inflammation contributes centrally to cardiovascular diseases, and anti-inflammatory treatments can reduce cardiovascular events. The JAK-STAT pathway is an emerging target in inflammation, mainly in rheumatoid arthritis (RA) and chronic myeloproliferative neoplasms (MPNs), disorders that heighten cardiovascular risk. The aim of this study was to review the international literature on the relationship between dysregulation of the JAK-STAT pathway in RA/MPNs and cardiovascular risk and on the potential cardiovascular effects of JAK-STAT inhibitors. The JAK-STAT pathway sustains inflammatory and thrombotic events in autoimmune disorders such as RA and MPNs. Here, an imbalance exists between pro- and anti-inflammatory cytokines [increased levels of interleukin (IL)-6, IL-1-β, tumour necrosis factor-α, decreased levels of IL-10] and the over-expression of some prothrombotic proteins, such as protein kinase Cε, on the surface of activated platelets. This pathway also operates in atherosclerotic cardiovascular disease. JAK-STAT inhibitors may reduce cardiovascular events and related deaths in such conditions, but the potential of these agents requires more studies, especially with regard to cardiovascular safety, and particularly for potential prothrombotic effects. JAK-STAT inhibitors merit consideration to curb heightened cardiovascular risk in patients with RA and MPNs, with rigorous assessment of the potential benefits and risks.