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American Journal of Hematology Dec 2020Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms (MPN) respectively characterized by clonal erythrocytosis and thrombocytosis;... (Review)
Review
DISEASE OVERVIEW
Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms (MPN) respectively characterized by clonal erythrocytosis and thrombocytosis; other disease features include leukocytosis, splenomegaly, thrombosis, bleeding, microcirculatory symptoms, pruritus and risk of leukemic or fibrotic transformation.
DIAGNOSIS
Bone marrow morphology remains the cornerstone of diagnosis. In addition, the presence of JAK2 mutation is expected in PV while approximately 90% of patients with ET express mutually exclusive JAK2, CALR or MPL mutations (so called driver mutations). In ET, it is most important to exclude the possibility of prefibrotic myelofibrosis.
SURVIVAL
Median survivals are approximately 15 years for PV and 18 years for ET; the corresponding values for patients age 40 or younger were 37 and 35 years. Certain mutations (mostly spliceosome) and abnormal karyotype might compromise survival in PV and ET. Life-expectancy in ET is inferior to the control population. Driver mutations have not been shown to affect survival in ET but risk of thrombosis is higher in JAK2 mutated cases. Leukemic transformation rates at 10 years are estimated at <1% for ET and 3% for PV.
THROMBOSIS RISK
In PV, two risk categories are considered: high (age > 60 years or thrombosis history present) and low (absence of both risk factors). In ET, four risk categories are considered: very low (age ≤ 60 years, no thrombosis history, JAK2 wild-type), low (same as very low but JAK2 mutation present), intermediate (age > 60 years, no thrombosis history, JAK2 wild-type) and high (thrombosis history present or age > 60 years with JAK2 mutation).
RISK-ADAPTED THERAPY
The main goal of therapy in both PV and ET is to prevent thrombohemorrhagic complications. All patients with PV require phlebotomy to keep hematocrit below 45% and once-daily or twice-daily aspirin (81 mg), in the absence of contraindications. Very low risk ET might not require therapy while aspirin therapy is advised for low risk disease. Cytoreductive therapy is recommended for high-risk ET and PV, but it is not mandatory for intermediate-risk ET. First-line drug of choice for cytoreductive therapy, in both ET and PV, is hydroxyurea and second-line drugs of choice are interferon-α and busulfan. We do not recommend treatment with ruxolutinib in PV, unless in the presence of severe and protracted pruritus or marked splenomegaly that is not responding to the aforementioned drugs.
NEW TREATMENT DIRECTIONS
Controlled studies are needed to confirm the clinical outcome value of twice-daily vs once-daily aspirin dosing and the therapeutic role of pegylated interferons and direct oral anticoagulants.
Topics: Age Factors; Aspirin; Busulfan; Calreticulin; Disease-Free Survival; Humans; Interferon-alpha; Janus Kinase 2; Mutation; Polycythemia Vera; Receptors, Thrombopoietin; Risk Assessment; Risk Factors; Survival Rate; Thrombocythemia, Essential
PubMed: 32974939
DOI: 10.1002/ajh.26008 -
Leukemia Dec 2021Polycythemia vera (PV) is a relatively indolent myeloid neoplasm with median survival that exceeds 35 years in young patients, but its natural history might be... (Review)
Review
Polycythemia vera (PV) is a relatively indolent myeloid neoplasm with median survival that exceeds 35 years in young patients, but its natural history might be interrupted by thrombotic, fibrotic, or leukemic events, with respective 20-year rates of 26%, 16%, and 4%. Current treatment strategies in PV have not been shown to prolong survival or lessen the risk of leukemic or fibrotic progression and instead are directed at preventing thrombotic complications. In the latter regard, two risk categories are considered: high (age >60 years or thrombosis history) and low (absence of both risk factors). All patients require phlebotomy to keep hematocrit below 45% and once-daily low-dose aspirin, in the absence of contraindications. Cytoreductive therapy is recommended for high-risk or symptomatic low-risk disease; our first-line drug of choice in this regard is hydroxyurea but we consider pegylated interferon as an alternative in certain situations, including in young women of reproductive age, in patients manifesting intolerance or resistance to hydroxyurea therapy, and in situations where treatment is indicated for curbing phlebotomy requirement rather than preventing thrombosis. Additional treatment options include busulfan and ruxolitinib; the former is preferred in older patients and the latter in the presence of symptoms reminiscent of post-PV myelofibrosis or protracted pruritus. Our drug choices reflect our appreciation for long-term track record of safety, evidence for reduction of thrombosis risk, and broader suppression of myeloproliferation. Controlled studies are needed to clarify the added value of twice- vs once-daily aspirin dosing and direct oral anticoagulants. In this invited review, we discuss our current approach to diagnosis, prognostication, and treatment of PV in general, as well as during specific situations, including pregnancy and splanchnic vein thrombosis.
Topics: History, 19th Century; History, 20th Century; History, 21st Century; Humans; Polycythemia Vera
PubMed: 34480106
DOI: 10.1038/s41375-021-01401-3 -
American Journal of Hematology May 2023Primary myelofibrosis (PMF) is a myeloproliferative neoplasm (MPN) characterized by stem cell-derived clonal myeloproliferation that is often but not always accompanied... (Review)
Review
DISEASE OVERVIEW
Primary myelofibrosis (PMF) is a myeloproliferative neoplasm (MPN) characterized by stem cell-derived clonal myeloproliferation that is often but not always accompanied by JAK2, CALR, or MPL mutations; additional features include bone marrow reticulin/collagen fibrosis, aberrant inflammatory cytokine expression, anemia, hepatosplenomegaly, extramedullary hematopoiesis (EMH), constitutional symptoms, cachexia, risk of leukemic progression, and shortened survival.
DIAGNOSIS
Bone marrow examination with cytogenetic and mutation studies provides integrated diagnostic information; presence of JAK2, CALR or MPL mutation is expected but not required.
NEW CLASSIFICATION SYSTEM
The International Consensus Classification distinguishes "prefibrotic" from "overtly fibrotic" PMF; the former might mimic essential thrombocythemia (ET) in its presentation. Approximately 15% of patients with ET or polycythemia vera (PV) might progress into post-ET/PV MF.
MUTATIONS
SRSF2, ASXL1, and U2AF1-Q157 mutations predict inferior survival in PMF; RAS/CBL mutations predict resistance to ruxolitinib therapy. Type 1/like CALR mutation is associated with superior survival.
KARYOTYPE
Very high-risk abnormalities include -7, inv (3), i(17q), +21, +19, 12p- and 11q-. Favorable risk abnormalities include normal karyotype or isolated +9, 13q-, 20q-, 1q abnormalities and loss of Y chromosome.
RISK STRATIFICATION
Contemporary prognostic systems include GIPSS (genetically-inspired prognostic scoring system) and MIPSS70+ version 2.0 (MIPSSv2; mutation-and karyotype-enhanced international prognostic scoring system). GIPSS is based exclusively on mutations and karyotype; MIPSSv2 includes, in addition, clinical risk factors.
RISK-ADAPTED THERAPY
Observation alone is advised for MIPSSv2 "low" and "very low" risk disease (estimated 10-year survival 56%-92%); allogeneic hematopoietic stem cell transplant (AHSCT) is the preferred treatment of choice for "very high" and "high" risk disease (estimated 10-year survival 0-13%), as well as in carefully selected patients with intermediate-risk disease (estimated 10-year survival 30%). Drug therapy in MF is currently palliative and targets anemia, splenomegaly, and constitutional symptoms. JAK2 INHIBITORS: Ruxolitinib, fedratinib, and pacritinib are FDA approved and respectfully utilized in patients failing treatment with hydroxyurea, ruxolitinib, or with platelet count <50 × 10 (9)/L. Momelotinib is another JAK2 inhibitor that is poised for approval sometime in 2023 and has shown erythropoietic benefits, in addition to affecting spleen and symptom responses.
OTHER TREATMENT MODALITIES
Splenectomy is considered for drug-refractory splenomegaly and involved field radiotherapy for non-hepatosplenic EMH and extremity bone pain.
NEW DIRECTIONS
New agents, alone or in combination with ruxolitinib, are currently under clinical trial investigation (ClinicalTrials.gov) and preliminary results were presented at the 2022 ASH annual meeting and highlighted in the current review.
Topics: Humans; Primary Myelofibrosis; Splenomegaly; Polycythemia Vera; Pyrazoles; Thrombocythemia, Essential; Mutation; Janus Kinase 2
PubMed: 36680511
DOI: 10.1002/ajh.26857 -
Blood Apr 2023BCR::ABL1-negative myeloproliferative neoplasms (MPNs) are clonal diseases originating from a single hematopoietic stem cell that cause excessive production of mature... (Review)
Review
BCR::ABL1-negative myeloproliferative neoplasms (MPNs) are clonal diseases originating from a single hematopoietic stem cell that cause excessive production of mature blood cells. The 3 subtypes, that is, polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), are diagnosed according to the World Health Organization (WHO) and international consensus classification (ICC) criteria. Acquired gain-of-function mutations in 1 of 3 disease driver genes (JAK2, CALR, and MPL) are the causative events that can alone initiate and promote MPN disease without requiring additional cooperating mutations. JAK2-p.V617F is present in >95% of PV patients, and also in about half of the patients with ET or PMF. ET and PMF are also caused by mutations in CALR or MPL. In ∼10% of MPN patients, those referred to as being "triple negative," none of the known driver gene mutations can be detected. The common theme between the 3 driver gene mutations and triple-negative MPN is that the Janus kinase-signal transducer and activator of transcription (JAK/STAT) signaling pathway is constitutively activated. We review the recent advances in our understanding of the early events after the acquisition of a driver gene mutation. The limiting factor that determines the frequency at which MPN disease develops with a long latency is not the acquisition of driver gene mutations, but rather the expansion of the clone. Factors that control the conversion from clonal hematopoiesis to MPN disease include inherited predisposition, presence of additional mutations, and inflammation. The full extent of knowledge of the mutational landscape in individual MPN patients is now increasingly being used to predict outcome and chose the optimal therapy.
Topics: Humans; Primary Myelofibrosis; Calreticulin; Receptors, Thrombopoietin; Myeloproliferative Disorders; Polycythemia Vera; Thrombocythemia, Essential; Janus Kinase 2; Mutation
PubMed: 36347013
DOI: 10.1182/blood.2022017578 -
American Family Physician Jun 2021Polycythemia vera is one of three stem-cell-derived myeloid malignancies commonly known as myeloproliferative neoplasms. It is characterized by erythrocytosis, often... (Review)
Review
Polycythemia vera is one of three stem-cell-derived myeloid malignancies commonly known as myeloproliferative neoplasms. It is characterized by erythrocytosis, often with associated leukocytosis and thrombocytosis. It has a significant negative impact on overall mortality and morbidity in the form of arterial and venous clots, symptoms of fatigue and pruritus, and conversion to leukemia and myelofibrosis. The World Health Organization's major diagnostic criteria include an elevated hemoglobin or hematocrit level, abnormal results on bone marrow biopsy, and presence of the Janus kinase 2 genetic mutation, which is present in approximately 98% of cases. The only minor criterion is a subnormal erythropoietin level, which helps differentiate polycythemia vera from common causes of secondary erythrocytosis such as smoking, sleep apnea, and testosterone use. First-line treatments, such as low-dose aspirin and goal-directed phlebotomy to a hematocrit level of less than 45% to reduce thrombotic events, improve quality of life and prolong survival. When indicated, cytoreductive therapy, primarily with hydroxyurea, can be added with consideration of second-line agents such as pegylated interferon-alfa, busulfan, and ruxolitinib, depending on the clinical scenario. Smoking cessation and cardiometabolic disease are modifiable risk factors that should be addressed to reduce the risk of thrombosis. Currently, no medications have been shown to cure the disease or to reduce the risk of conversion to leukemia and myelofibrosis.
Topics: Antineoplastic Agents; Fibrinolytic Agents; Genetic Markers; Humans; Hydroxyurea; Janus Kinase 2; Mutation; Phlebotomy; Polycythemia Vera
PubMed: 34060791
DOI: No ID Found -
American Journal of Hematology Jan 2023A group of international experts, including hematopathologists, oncologists, and geneticists were recently summoned (September 2021, Chicago, IL, USA) to update the... (Review)
Review
A group of international experts, including hematopathologists, oncologists, and geneticists were recently summoned (September 2021, Chicago, IL, USA) to update the 2016/17 World Health Organization classification system for hematopoietic tumors. After careful deliberation, the group introduced the new International Consensus Classification (ICC) for Myeloid Neoplasms and Acute Leukemias. This current in-depth review focuses on the ICC-2022 category of JAK2 mutation-prevalent myeloproliferative neoplasms (MPNs): essential thrombocythemia, polycythemia vera, primary myelofibrosis, and MPN, unclassifiable. The ICC MPN subcommittee chose to preserve the primary role of bone marrow morphology in disease classification and diagnostics, while also acknowledging the complementary role of genetic markers for establishing clonality, facilitating MPN subtype designation, and disease prognostication.
Topics: Humans; Consensus; Myeloproliferative Disorders; Leukemia; Polycythemia Vera; Bone Marrow; Janus Kinase 2; Mutation
PubMed: 36200127
DOI: 10.1002/ajh.26751 -
Cells Dec 2021Classical BCR-ABL-negative myeloproliferative neoplasms (MPN) are a heterogeneous group of hematologic malignancies, including essential thrombocythemia (ET),... (Review)
Review
Classical BCR-ABL-negative myeloproliferative neoplasms (MPN) are a heterogeneous group of hematologic malignancies, including essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF), as well as post-PV-MF and post-ET-MF. Progression to more symptomatic disease, such as overt MF or acute leukemia, represents one of the major causes of morbidity and mortality. There are clinically evident but also subclinical types of MPN progression. Clinically evident progression includes evolution from ET to PV, ET to post-ET-MF, PV to post-PV-MF, or pre-PMF to overt PMF, and transformation of any of these subtypes to myelodysplastic neoplasms or acute leukemia. Thrombosis, major hemorrhage, severe infections, or increasing symptom burden (e.g., pruritus, night sweats) may herald progression. Subclinical types of progression may include increases in the extent of bone marrow fibrosis, increases of driver gene mutational allele burden, and clonal evolution. The underlying causes of MPN progression are diverse and can be attributed to genetic alterations and chronic inflammation. Particularly, bystander mutations in genes encoding epigenetic regulators or splicing factors were associated with progression. Finally, comorbidities such as systemic inflammation, cardiovascular diseases, and organ fibrosis may augment the risk of progression. The aim of this review was to discuss types and mechanisms of MPN progression and how their knowledge might improve risk stratification and therapeutic intervention. In view of these aspects, we discuss the potential benefits of early diagnosis using molecular and functional imaging and exploitable therapeutic strategies that may prevent progression, but also highlight current challenges and methodological pitfalls.
Topics: Disease Progression; Fusion Proteins, bcr-abl; Humans; Leukemia; Mutation; Myelodysplastic Syndromes; Myeloproliferative Disorders; Polycythemia Vera; Primary Myelofibrosis; Thrombocythemia, Essential; Thrombosis
PubMed: 34944059
DOI: 10.3390/cells10123551 -
Blood Jul 2019Since its discovery, polycythemia vera (PV) has challenged clinicians responsible for its diagnosis and management and scientists investigating its pathogenesis. As a... (Review)
Review
Since its discovery, polycythemia vera (PV) has challenged clinicians responsible for its diagnosis and management and scientists investigating its pathogenesis. As a clonal hematopoietic stem cell (HSC) disorder, PV is a neoplasm but its driver mutations result in overproduction of morphologically and functionally normal blood cells. PV arises in an HSC but it can present initially as isolated erythrocytosis, leukocytosis, thrombocytosis, or any combination of these together with splenomegaly or myelofibrosis, and it can take years for a true panmyelopathy to appear. PV shares the same mutation as essential thrombocytosis and primary myelofibrosis, but erythrocytosis only occurs in PV. However, unlike secondary causes of erythrocytosis, in PV, the plasma volume is frequently expanded, masking the erythrocytosis and making diagnosis difficult if this essential fact is ignored. PV is not a monolithic disorder: female patients deregulate fewer genes and clinically behave differently than their male counterparts, while some PV patients are genetically predisposed to an aggressive clinical course. Nevertheless, based on what we have learned over the past century, most PV patients can lead long and productive lives. In this review, using clinical examples, I describe how I diagnose and manage PV in an evidence-based manner without relying on chemotherapy.
Topics: Adult; Aged, 80 and over; Biomarkers; Combined Modality Therapy; Disease Management; Disease Susceptibility; Evidence-Based Medicine; Female; Hematopoietic Stem Cells; Humans; Male; Middle Aged; Polycythemia Vera; Treatment Outcome
PubMed: 31151982
DOI: 10.1182/blood.2018834044 -
Journal of Clinical Oncology : Official... Jul 2023Polycythemia vera (PV) is characterized by JAK/STAT activation, thrombotic/hemorrhagic events, systemic symptoms, and disease transformation. In high-risk PV,... (Randomized Controlled Trial)
Randomized Controlled Trial
PURPOSE
Polycythemia vera (PV) is characterized by JAK/STAT activation, thrombotic/hemorrhagic events, systemic symptoms, and disease transformation. In high-risk PV, ruxolitinib controls blood counts and improves symptoms.
PATIENTS AND METHODS
MAJIC-PV is a randomized phase II trial of ruxolitinib versus best available therapy (BAT) in patients resistant/intolerant to hydroxycarbamide (HC-INT/RES). Primary outcome was complete response (CR) within 1 year. Secondary outcomes included duration of response, event-free survival (EFS), symptom, and molecular response.
RESULTS
One hundred eighty patients were randomly assigned. CR was achieved in 40 (43%) patients on ruxolitinib versus 23 (26%) on BAT (odds ratio, 2.12; 90% CI, 1.25 to 3.60; = .02). Duration of CR was superior for ruxolitinib (hazard ratio [HR], 0.38; 95% CI, 0.24 to 0.61; < .001). Symptom responses were better with ruxolitinib and durable. EFS (major thrombosis, hemorrhage, transformation, and death) was superior for patients attaining CR within 1 year (HR, 0.41; 95% CI, 0.21 to 0.78; = .01); and those on ruxolitinib (HR, 0.58; 95% CI, 0.35 to 0.94; = .03). Serial analysis of V617F variant allele fraction revealed molecular response was more frequent with ruxolitinib and was associated with improved outcomes (progression-free survival [PFS] = .001, EFS = .001, overall survival = .01) and clearance of V617F stem/progenitor cells. 1 mutations predicted for adverse EFS (HR, 3.02; 95% CI, 1.47 to 6.17; = .003). The safety profile of ruxolitinib was as previously reported.
CONCLUSION
The MAJIC-PV study demonstrates ruxolitinib treatment benefits HC-INT/RES PV patients with superior CR, and EFS as well as molecular response; importantly also demonstrating for the first time, to our knowledge, that molecular response is linked to EFS, PFS, and OS.
Topics: Humans; Polycythemia Vera; Treatment Outcome; Hydroxyurea; Nitriles; Hemorrhage
PubMed: 37126762
DOI: 10.1200/JCO.22.01935 -
Blood Apr 2023Polycythemia vera (PV) is a hematopoietic stem cell neoplasm defined by activating somatic mutations in the JAK2 gene and characterized clinically by overproduction of...
Polycythemia vera (PV) is a hematopoietic stem cell neoplasm defined by activating somatic mutations in the JAK2 gene and characterized clinically by overproduction of red blood cells, platelets, and neutrophils; a significant burden of disease-specific symptoms; high rates of vascular events; and evolution to a myelofibrosis phase or acute leukemia. The JAK2V617F variant allele frequency (VAF) is a key determinant of outcomes in PV, including thrombosis and myelofibrotic progression. Here, we critically review the dynamic role of JAK2V617F mutation burden in the pathogenesis and natural history of PV, the suitability of JAK2V617F VAF as a diagnostic and prognostic biomarker, and the utility of JAK2V617F VAF reduction in PV treatment.
Topics: Humans; Alleles; Janus Kinase 2; Mutation; Polycythemia Vera; Primary Myelofibrosis; Thrombosis
PubMed: 36745865
DOI: 10.1182/blood.2022017697