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Thromboembolic events and bleeding are known complications in essential thrombocythaemia (ET) and polycythaemia vera (PV). Using multiple Swedish health care registers, we assessed the rate of arterial and venous events, major bleeding, all-cause stroke and all-cause mortality in ET and PV compared to matched controls. For each patient with ET (n = 3141) and PV (n = 2604), five matched controls were randomly selected. In total, 327 and 405 arterial or venous events were seen in the group of ET and PV patients respectively. Compared to corresponding controls, the rate of venous thromboembolism, major bleeding and all-cause mortality per 100 treatment years was significantly increased among both ET (0.63, 0.79 and 3.70) and PV patients (0.94, 1.20 and 4.80). The PV patients also displayed a significantly higher rate of arterial events and all-cause stroke compared to controls. When dividing the cohort into age groups, we found a significantly higher rate of arterial and venous events in all age groups of PV patients, and the rate of all-cause mortality was significantly higher in both ET and PV patients in all ages above the age of 50. This study confirms that PV and ET are diseases truly marked by thromboembolic complications and bleeding., (© 2024 The Authors. British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

Introduction: Essential thrombocythemia (ET) involves the proliferation of megakaryocytes and platelets and is associated with an increased risk of thrombosis. We aimed to evaluate thrombotic risks in patients with epigenetic regulator mutations and generate a model to predict thrombosis in ET., Materials and Methods: This cohort study enrolled patients aged > 15 years diagnosed with ET at the Songklanakarind Hospital between January 2002 and December 2019. Twenty-five targeted gene mutations, including somatic driver mutations ( JAK2, CALR, MPL ), epigenetic regulator mutations ( TET2, DNMT3A , IDH1 , IDH2 , TET2 , ASXL1, EZH2 , SF3B1 , SRSF2 ) and other genes relevant to myeloid neoplasms, were identified using next-generation sequencing. Thrombotic events were confirmed based on clinical condition and imaging findings, and thrombotic risks were analyzed using five survival models with the recurrent event method., Results: Ninety-six patients were enrolled with a median follow-up of 6.91 years. Of these, 15 patients experienced 17 arterial thrombotic events in total. Patients with JAK2 mutation and IDH1 mutation had the highest frequency of thrombotic events with somatic driver mutations (17.3%) and epigenetic regulator mutations (100%). The 10-year thrombosis-free survival rate was 81.3% (95% confidence interval: 72.0-91.8%). IDH1 mutation was a significant factor for thrombotic risk in the multivariate analysis for all models. The Prentice, William, and Peterson (PWP) gap-time model was the most appropriate prediction model., Conclusions: The PWP gap-time model was a good predictive model for thrombotic risk in patients with ET. IDH1 mutation was significant risk factors for thrombosis; however, further studies with a larger sample size should confirm this and provide more insight., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objectives: In patients with essential thrombocythemia (ET), after the JAK2V617F driver mutation, mutations in CALR are common (classified as type 1, 52-bp deletion or type 2, 5-bp insertion). CALR mutations have generally been associated with a lower risk of thrombosis. This study aimed to confirm the impact of CALR mutation type on thrombotic risk., Methods: We retrospectively investigated 983 ET patients diagnosed in Spanish and Polish hospitals., Results: With 7.5 years of median follow-up from diagnosis, 155 patients (15.8%) had one or more thrombotic event. The 5-year thrombosis-free survival (TFS) rate was 83.8%, 91.6% and 93.9% for the JAK2V617F, CALR-type 1 and CALR-type 2 groups, respectively (P = .002). Comparing CALR-type 1 and CALR-type 2 groups, TFS for venous thrombosis was lower in CALR-type 1 (P = .046), with no difference in TFS for arterial thrombosis observed. The cumulative incidence of thrombosis was significantly different comparing JAK2V617F vs CALR-type 2 groups but not JAK2V617F vs CALR-type 1 groups. Moreover, CALR-type 2 mutation was a statistically significant protective factor for thrombosis with respect to JAK2V617F in multivariate logistic regression (OR: 0.45, P = .04) adjusted by age., Conclusions: Our results suggest that CALR mutation type has prognostic value for the stratification of thrombotic risk in ET patients., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

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., (© 2020 Wiley Periodicals LLC.)

Objective: We report an extension study of patients with essential thrombocythaemia (ET) in the Hungarian Myeloproliferative Neoplasm (HUMYPRON) Registry, which demonstrated that over 6 years anagrelide significantly decreased the number of patients experiencing minor arterial and minor venous thrombotic events (TEs) vs hydroxyurea+aspirin., Methods: Data on patients with ET were collected through completion of a questionnaire developed according to 2008 WHO diagnostic criteria and with regard to Landolfi, Tefferi and IPSET criteria for thrombotic risk. Data were entered into the registry from 14 haematological centres. TEs, secondary malignancies, disease progression and survival were compared between patients with ET treated with anagrelide (n = 116) and with hydroxyurea+aspirin (n = 121)., Results: Patients were followed for (median) 10 years. A between-group difference in the number of patients with TEs was observed (25.9% anagrelide vs 38.0% hydroxyurea+aspirin; P = .052). Minor arterial events were more frequently reported in the hydroxyurea+aspirin group (P < .001); there were marginally more reports of major arterial events in the anagrelide group (P = .049). TE prior to diagnosis was found to significantly influence TE incidence (P > .001). Progression-free survival (P = .004) and survival (P = .001) were significantly increased for the anagrelide group vs hydroxyurea+aspirin., Conclusions: Anagrelide reduced TEs, and increased progression-free and overall survival vs hydroxyurea+aspirin over (median) 10 years., (© 2020 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To explore the relative importance of risk factors, treatments, and blood counts for the occurrence of vascular complications and their impact on life expectancy in essential thrombocythemia (ET) and polycythemia vera (PV)., Methods: Nested case-control study within the Swedish MPN registry. From a cohort of 922 ET patients and 763 PV patients, 71 ET and 81 PV cases with vascular complications were compared with matched controls., Results: Incidence of vascular complications was 2.0 and 3.4 events per 100 patient-years in ET and PV, respectively. At diagnosis, no significant risk factor differences were observed between cases and controls in neither of the diseases. At the time of vascular event, ET complication cases did not differ significantly from controls but in PV, cases had significantly higher WBCs and were to a lesser extent treated with anti-thrombotic and cytoreductive therapy. Life expectancy was significantly decreased in both ET and PV cases compared with controls., Conclusions: The risk of vascular complications is high in both ET and PV, and these complications have a considerable impact on life expectancy. The protective effect of anti-thrombotic and cytoreductive therapy for vascular complications in PV underscores the importance of avoiding undertreatment., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

To explore the risk factors of thrombosis in patients with JAK2 V617F -mutated myeloproliferative neoplasms (MPNs), a cohort of 1537 Chinese patients with JAK2 V617F -mutated MPN was retrospectively analyzed. The Kaplan-Meier method and multivariate Cox analysis were used to study the risk factors of thrombosis in patients with JAK2 V617F -mutated MPN. Among the 1537 MPN patients, 931, 468, and 138 had polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), respectively. The median follow-up time was 7 years (range 1-47), and 12.8% of patients (197/1537) died during this period. A total of 16.8% (259/1399) of PV and ET patients had secondary myelofibrosis, and 2.5% (38/1537) of patients developed acute myeloid leukemia (AML). Thrombotic events occurred in 43.9% (675/1537) of patients, among which 91.4% (617/675) were arterial thrombosis and 16.6% (112/675) were venous thrombosis. The number of thrombotic events in PV, ET, and PMF patients was 439 (47.2%), 197 (42.1%) and 39 (28.2%), respectively. The multivariate analysis indicated that age ≥60 years old, HCT ≥48%, at least one cardiovascular risk factor, a history of thrombosis, and JAK2 V617F allele burden (V617F%) ≥50% are risk factors for thrombosis in JAK2 V617F -mutated MPN. According to the results of the multivariate analysis, a risk model of thrombosis was established and comprised low-risk (0 points), intermediate-risk (1 points) and high-risk (≥2 points) groups, among which the incidence of thrombosis was 9.1%, 33.7% and 72.9%. For elderly patients with JAK2 V617F -mutated MPN and a history of thrombosis, reducing the V617F%, controlling HCT and preventing cardiovascular risk factors are necessary measures to prevent thrombosis., (© 2020 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

The conventional thrombotic risk stratification in essential thrombocythemia (ET) distinguishes patients in two risk groups based on previous thrombosis and age (< or >60). The IPSET-thrombosis takes into account four risk factors: age greater than 60 years and the presence of CV risk factors, thrombosis history and JAK2 V617F presence. The revised IPSET-thrombosis uses three adverse variables to delineate four risk categories: age greater than 60, thrombosis history, and JAK2 V617F presence. We compared different risk models in the estimation of thrombotic risk in 191 patients with ET and the role of specific driver mutations affecting overall survival, according to thrombotic risk. We also evaluated the mutational status of patients showing history of thrombosis or cardiovascular events versus patients who did not. Finally, we verified whether the thrombotic risk had a significant impact on survival in our ET patients. The data analysis has been performed through the conventional statistics and overall survival estimated by using the Kaplan-Meyer method. Interestingly, either using the traditional system for thrombotic risk or the IPSET-t prognostic score or the current stratification for the thrombotic risk, high-risk patients are always highly represented. This evidence is of note, being the high-risk category indicated for cytoreduction, affecting quality of life, despite the good overall prognosis of patients with ET diagnosis in general. The analysis of overall survival in our patients, according to different models for thrombotic risk, highlighted the poor prognosis of high-risk patients compared with those with a lower thrombotic risk, in particular when using traditional stratification and current stratification. In conclusion, the occurrence of thrombotic or cardiovascular events represents one of the most severe complications at diagnosis or during follow-up of ET despite current recommendations, having a significant impact on morbidity and survival., (© 2019 John Wiley & Sons, Ltd.)

We aimed to validate the MYelofibrosis SECondary to PV and ET prognostic model (MYSEC-PM) in 159 patients with myelofibrosis secondary to polycythemia vera (PV) and essential thrombocythemia (ET) from the European Society for Blood and Marrow Transplantation registry undergoing transplantation from matched siblings or unrelated donors. Furthermore, we aimed to test its prognostic performance in comparison with the Dynamic International Prognostic Scoring System (DIPSS). Score performance was analyzed using the concordance index (C): the probability that a patient who experienced an event had a higher risk score than a patient who did not (C > .5 suggesting predictive ability). Median follow-up of the total cohort was 41 months (range, 34 to 54), 45 months in post-PV and 38 months in post-ET myelofibrosis. Survival at 1, 2, and 4 years was 70% (95% CI, 63% to 77%), 61% (95% CI, 53% to 69%), and 52% (95% CI, 43% to 61%) for the total cohort; 70% (95% CI, 59% to 80%), 61% (95% CI, 49% to 73%), and 51% (95% CI, 38% to 64%) for post-PV; and 71% (95% CI, 61% to 81%), 61% (95% CI, 50% to 72%), and 54% (95% CI, 42% to 66%) for post-ET myelofibrosis (P = .78). Overall, the DIPSS was not significantly predictive of outcome (P = .28). With respect to the MYSEC-PM, overall survival at 4 years was 69% for the low-risk, 55% for the intermediate 1-risk, 47% for the intermediate 2-risk, and 22% (0% to 45%) for the high-risk groups. The prognostic model was predictive of survival overall (P = .05), whereas groups with intermediate 2 and high risk showed no significant difference (P = .44). Assessment of prognostic utility yielded a C-index of .575 (95% CI, .502 to .648) for the DIPSS, whereas assessment of the MYSEC-PM resulted in a C-statistics of .636 (95% CI, .563 to .708), indicating improvement in prediction of post-transplant survival using the new MYSEC-PM. In addition, transplantations from an unrelated donor in comparison with an HLA-identical sibling showed worse outcome (P = .04), and transplant recipients seropositive for cytomegalovirus in comparison with seronegative recipients (P = .01) showed worse survival. In conclusion, incorporating transplant-specific and clinical and mutational information together with the MYSEC-PM may enhance risk stratification., (Copyright © 2019 American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

Objective: To document the Mayo Clinic decades-long experience with myeloproliferative neoplasms (MPNs) and provide mature risk-stratified survival data and disease complication estimates., Patients and Methods: All Mayo Clinic patients with World Health Organization-defined MPNs constituted the core study group and included those with polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF)., Results: A total of 3023 consecutive patients (median age, 62 years; range, 18-96 years) were considered: 665 PV, 1076 ET, and 1282 PMF. From October 27, 1967, through December 29, 2017, 1631 deaths (54%), 183 leukemic transformations (6%), 244 fibrotic progressions (14%), and 516 thrombotic events (17%) were recorded. Median overall survival (OS) was 18 years for ET, 15 years for PV, and 4.4 years for PMF (P<.05 for all intergroup comparisons). Inferior survival was documented in patients with ET diagnosed more recently (post-1990) (P<.001), whereas survival data were time independent in PV and PMF. After conventional risk stratification, OS in low-risk ET and low-risk PV were superimposed (P=.89) but each differed significantly from that of age- and sex-matched controls (P<.001). Leukemia-free survival was similar for ET and PV (P=.22) and significantly worse with PMF (P<.001). Compared with ET, PV was associated with higher risk of fibrotic progression (P<.001). Thrombosis risk after diagnosis was highest in PV and lowest in PMF (P=.002 for PV vs ET; P=.56 for ET vs PMF; and P=.001 for PV vs PMF)., Conclusion: This study provides the most mature survival and outcomes data in MPNs and highlights MPN subgroup risk categorization as key in appraising disease natural history. The OS was only marginally better in ET compared with PV, and PV displayed a higher risk of thrombosis and fibrotic progression., (Copyright © 2018 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.)

ABSTRACTBackground: Current guidelines recommend hydroxyurea (HU) as frontline therapy for patients with high-risk essential thrombocythemia (ET) to prevent thrombosis. However, little is known about the impact of HU on thrombosis or survival among these patients in the real-world setting., Patients and Methods: A retrospective cohort study was conducted of older adults (aged ≥66 years) diagnosed with ET from 2007 through 2013 using the linked SEER-Medicare database. Multivariable Cox proportional hazards regression models were used to assess the effect of HU on overall survival, and multivariable competing risk models were used to assess the effect of HU on the occurrence of thrombotic events., Results: Of 1,010 patients, 745 (73.8%) received HU. Treatment with HU was associated with a significantly lower risk of death (hazard ratio [HR], 0.52; 95% CI, 0.43-0.64; P<.01). Every 10% increase in HU proportion of days covered was associated with a 12% decreased risk of death (HR, 0.88; 95% CI, 0.86-0.91; P<.01). Compared with nonusers, HU users also had a significantly lower risk of thrombotic events (HR, 0.51; 95% CI, 0.41-0.64; P<.01)., Conclusions: Although underused in our study population, HU was associated with a reduced incidence of thrombotic events and improved overall survival in older patients with ET.

First-line cytoreductive drug of choice in high risk essential thrombocythemia (ET) is currently hydroxyurea, a practice based on the results of a randomized study; second-line drugs of choice include pegylated interferon-α, busulfan and anagrelide. Anagrelide clinical trials were pioneered by the late Murray N. Silverstein (1928-1998) of the Mayo Clinic whose studies led to FDA approval in March 1997. The current study represents a retrospective examination of the potential impact of anagrelide therapy on survival and disease complications in ET. 1076 patients with ET were considered (median age 58 years; females 63%); risk distribution, according to the international prognostic score for ET (IPSET), was 28% high, 42% intermediate, and 30% low. Overall (OS), myelofibrosis-free (MFFS) and thrombosis-free survival data were compared for ET patients diagnosed before and after the 1997 FDA approval date for anagrelide; a significant difference was apparent in OS (P = .006; HR 1.4, 95% CI 1.1-1.7) and MFFS (P < .001; HR 4.2, 95% CI 2.7-6.5), in favor of patients diagnosed prior to 1997; the difference was sustained during multivariable analysis that included IPSET. Similarly stratified survival data in polycythemia vera (n = 665) and primary myelofibrosis (n = 1282) showed no similar impact on survival (P = .3 and .17, respectively). The current study represents a retrospective analysis and suggests significantly decreased OS and MFFS in ET patients diagnosed after the FDA approval date of anagrelide. Whether or not anagrelide therapy was to blame for the worsening of OS and MFFS over time cannot be assumed and requires validation in a prospective study., (© 2018 Wiley Periodicals, Inc.)

Purpose: Cytoreductive therapy is beneficial in patients with essential thrombocythemia (ET) at high risk of thrombosis. However, its value in those lacking high-risk features remains unknown. This open-label, randomized trial compared hydroxycarbamide plus aspirin with aspirin alone in patients with ET age 40 to 59 years and without high-risk factors or extreme thrombocytosis., Patients and Methods: Patients were age 40 to 59 years and lacked a history of ischemia, thrombosis, embolism, hemorrhage, extreme thrombocytosis (platelet count ≥ 1,500 × 10 9 /L), hypertension, or diabetes requiring therapy. In all, 382 patients were randomly assigned 1:1 to hydroxycarbamide plus aspirin or aspirin alone. The composite primary end point was time to arterial or venous thrombosis, serious hemorrhage, or death from vascular causes. Secondary end points were time to first arterial or venous thrombosis, first serious hemorrhage, death, incidence of transformation, and patient-reported quality of life., Results: After a median follow-up of 73 months and a total follow-up of 2,373 patient-years, there was no significant difference between the arms in the likelihood of patients reaching the primary end point (hazard ratio, 0.98; 95% CI, 0.42 to 2.25; P = 1.0). The incidence of significant vascular events was low, at 0.93 per 100 patient-years (95% CI, 0.61 to 1.41). There were also no differences in overall survival; in the composite end point of transformation to myelofibrosis, acute myeloid leukemia, or myelodysplasia; in adverse events; or in patient-reported quality of life., Conclusion: In patients with ET age 40 to 59 years and lacking high-risk factors for thrombosis or extreme thrombocytosis, preemptive addition of hydroxycarbamide to aspirin did not reduce vascular events, myelofibrotic transformation, or leukemic transformation. Patients age 40 to 59 years without other clinical indications for treatment (such as previous thrombosis or hemorrhage) who have a platelet count < 1,500 × 10 9 /L should not receive cytoreductive therapy.

A new entity, namely early/prefibrotic primary myelofibrosis (PMF), was introduced as a subtype of PMF in the 2016 revised World Health Organization (WHO) criteria for myeloproliferative neoplasms (MPN). It was diagnosed based on histopathological features of bone marrow (BM) biopsy specimens together with clinical parameters [leukocytosis, anemia, elevated lactate dehydrogenase (LDH) values, and splenomegaly]. The aim of this study was to evaluate the prevalence of early/prefibrotic PMF in patients who were previously diagnosed with ET, and to compare clinical features at diagnosis and outcomes between early/prefibrotic PMF and essential thrombocythemia (ET) patients. BM biopsy samples obtained at the time of ET diagnosis were available in 42 patients. Sample reevaluation according to the 2016 revised WHO criteria revealed that early/prefibrotic PMF accounted for 14% of patients who were previously diagnosed with ET, which was comparable to the rates in previous reports. Compared to patients with ET, patients with early/prefibrotic PMF had higher LDH values and higher frequencies of splenomegaly. Overall, myelofibrosis-free and acute myeloid leukemia-free survivals were comparable between the 2 groups. Accurate diagnosis is required to clarify the clinical features of Japanese ET patients.

Recently, the myelofibrosis secondary to PV and ET prognostic model (MYSEC-PM) was introduced to assess prognosis in myelofibrosis (MF) secondary to polycythemia vera and essential thrombocythemia (post-PV and post-ET MF), replacing the International Prognostic Scoring System (IPSS) and/or Dynamic IPSS (DIPSS) that was applied for primary MF (PMF). In a cohort of 421 ruxolitinib (RUX)-treated patients (post-PV and post-ET MF: 44.2%), we evaluated the following: (1) disease phenotype, responses, and toxicity to RUX; and (2) performance of the MYSEC-PM in post-PV or post-ET MF. While the IPSS failed to correctly stratify post-PV or post-ET MF patients at diagnosis, the MYSEC-PM identified 4 risk categories projected at significantly different survival probability (P < .001). Additionally, the MYSEC-PM maintained a prognostic value in post-PV and post-ET MF also when used over time, at RUX start. Notably, the MYSEC-PM reclassified 41.8% and 13.6% of patients into a lower and higher risk category, respectively. Finally, patients at intermediate-1 risk had significantly higher spleen responses and lower hematological toxicities compared to higher risk patients. Compared to PMF, post-PV and post-ET MF presented a more hyperproliferative disease, with higher leukocyte and/or platelet count and hemoglobin levels both at diagnosis and at RUX start. Despite comparable response rates, post-PV and post-ET MF had lower rate of RUX-induced anemia and thrombocytopenia at 3 and 6 months. The study validates MYSEC-PM in post-PV and post-ET MF prognostication. Post-PV or post-ET MF represents a separate entity compared to PMF in terms of clinical manifestations and toxicity to RUX., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: We examined the prognostic factors to validate previous prognostic models for survival and thrombosis with large-scale data on Japanese patients with essential thrombocythemia (ET)., Method: We conducted a study in 352 patients with ET to validate previous prognostic models and search for new prognostic factors., Results: The International Prognostic Score for essential thrombocythemia (IPSET), the conventional risk classification and the International Prognostic Score for thrombosis in essential thrombocythemia (IPSET-T) were confirmed to be reproducible in Japanese patients. However, no significant difference was observed between the low-risk and intermediate-risk categories according to the revised IPSET-T, which does not allow direct comparison of the four risk groups. We reevaluated the risk using a modified revised IPSET-T, which was derived from the revised IPSET-T by scoring the factors as follows: one point for age > 60 years, two points for past history of thrombosis, two points for JAK2 gene mutation-positive; total points of 0 = very low risk, 1 =  low risk, 2 =  intermediate risk, 3 and above = high risk, with significantly different thrombosis-free survival., Conclusion: The modified revised IPSET-T has been useful for 4-group stratification to predict a population that requires therapeutic intervention, irrespective of the treatment regimens., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Introduction: The management of pregnancy during the course of BCR-ABL1-negative myeloproliferative neoplasms (MPN) is an increasingly relevant problem. This is mostly due to earlier and better diagnosis of MPN together with the trend in modern society toward delaying pregnancy until later life. Areas Covered: The present review aims to provide an overview of the available literature data concerning outcome of pregnancy in MPN. Possible therapeutic modalities are discussed and a management algorithm is suggested. Expert Commentary: Most data are available for women with essential thrombocythemia and we present 793 published pregnancies. Live birth rate is 68.5% with 31.5% miscarriages. Spontaneous abortion is the most frequent complication with 26.5%, followed by stillbirth with 4.8%. Maternal complications are relatively low with 1.8% major thrombotic and 2.4% major bleeding events. In polycythemia vera the situation is clinically more complex and roughly 150 pregnancy reports are available. There is very limited information in primary myelofibrosis with less than 20 reported pregnancies. With active management including control of blood counts, aspirin, low molecular weight heparin and in higher risk cases interferon alpha pregnancy in MPN is manageable with a success rate not far below the normal situation with 80%.

Polycythemia vera (PV) and essential thrombocythemia (ET) are associated with life-threatening thrombohemorrhagic events, and disease progression and development of non-hematological malignancies also reduce long-term survival. We retrospectively surveyed thrombohemorrhagic events and overall survival (OS) in 62 PV and 117 ET patients. The cumulative incidences of thrombohemorrhagic events in PV and ET patients were 11.3 and 10.3%, and the incidence rates were 2.42 and 1.85 per 100 person-years. The combined incidence rates of disease progression and development of non-hematological malignancies in PV and ET patients were 1.73 and 1.69 per 100 person-years. The incidence rates of thrombohemorrhagic events in our Japanese PV/ET patients were lower than those reported by most Western studies, but were comparable to those in the largest prospective observational study in ET patients. The combined incidence rates of disease progression and development of non-hematological malignancies were similar between Japanese and Western PV/ET patients. In ET patients, the conventional risk stratification model based on the presence of advanced age or history of thrombosis was useful to predict thrombosis risk, and both the conventional model and the International Prognostic Score of thrombosis in ET based on the above 2 risk factors plus increased leukocyte count could predict poor survival.

JAK2, CALR, MPL and triple-negative mutational status has a direct impact on symptom severity and disease burden assessed by MPN10 score in myeloproliferative neoplasms (MPNs). Among 93 patients; median MPN10 score was 48 (5-76) in JAK2 mutants versus 25 (4-80) in JAK2 negative (p < .001); 22.5 (4-65) in CALR mutants versus 35 (5-80) in CALR negative (p < .050) and 21 (10-48) in triple negative versus 40 (4-80) in JAK2/CALR/MPL mutants (p < .001). At three years, progression free and overall survival of JAK2-positive versus JAK2-negative patients were 62% versus 100% (p < .001); 85% versus 100% (p = .011) and were 100% versus 78% (p = .067); 100% versus 92% (p = .197) in CALR-positive versus CALR-negative patients and 100% versus 75% (p = .004); 100% versus 90% (p = .015) in triple negative versus mutant patients, respectively. MPN10 score in association with driver gene mutations can be used as a predictor of survival in MPN patients.

Severe thrombocytopenia (platelets <50 × 10 9 /L) is associated with very poor outcome of patients with myelofibrosis (MF). As patients with primary myelofibrosis (PMF) differ from patients with postessential thrombocythemia (PET-MF) and postpolycythemia vera myelofibrosis (PPV-MF), we aimed to evaluate the significance of low platelets among these patients. We present clinical characteristics and outcome of patients with either PMF, PPV-MF, or PET-MF, and thrombocytopenia who presented to our institution between 1984 and 2015. Of 1269 patients (877 PMF, 212 PPV-MF, 180 PET-MF), 11% and 14% had platelets either <50 × 10 9 /L or between 50-100 × 10 9 /L, respectively. Patients with platelets <50 × 10 9 /L were most anemic and transfusion dependent, had highest blast count and unfavorable karyotype. In general, their overall and leukemia-free survival was the shortest with median time of 15 and 13 months, respectively; with incidence of acute leukemia almost twice as high as in the remaining patients (6.9 vs 3.6 cases per 100 person-years). Nevertheless, this observation remains mostly significant for patients with PMF, as those with PEV/PVT-MF have already significantly inferior prognosis with platelets <100 × 10 9 /L., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

An accurate histological diagnosis may distinguish essential thrombocythaemia (ET) from early primary myelofibrosis (early-PMF), which is associated with worse outcome. Outcome of ET is also negatively affected by the presence of the JAK2 V617F mutation. To investigate the impact of JAK2 V617F mutation burden and histology on outcome, we collected 475 WHO-diagnosed ET (69.2%) or early-PMF JAK2 V617F -positive patients followed in 4 Italian haematology centers. JAK2 V617F allele burden was ≤50% in 90% and 87% of ET and early-PMF patients, respectively (P = .34). During follow-up, 32 (9.7%) ET and 18 (12.3%) early-PMF patients experienced 59 thrombotic events, and 27 patients (5.6%) and 6 (1.2%) patients evolved to myelofibrosis and acute leukemia, respectively. At last contact, 28 (5.8%) patients had died. In early-PMF compared to ET, the 10-year mortality rates (6.7% and 4.3%, P = .73), leukemic transformation rates (1.4% and 1.2%, P = .45), and thrombosis rates (16.7% and 12.2%, P = .12) were comparable. Only progression to overt myelofibrosis at 10 years was significantly worse (11.4% and 1.5%, P = .004). In multivariate analysis, a higher (>50%) JAK2 V617F burden was significantly correlated with fibrotic progression and histology. Considering JAK2 V617F -positive disease, a higher (>50%) JAK2 V617F burden and histological classification are independent prognostic risk factors for disease progression. These findings reinforce the need for standardized detection of this mutation., (Copyright © 2017 John Wiley & Sons, Ltd.)

Essential thrombocythemia (ET) is a chronic myeloproliferative neoplasm that is associated with diminished quality of life, thrombohemorrhagic complications, and transformation to myelofibrosis (MF) and acute leukemia (AML). The important recent discoveries of driver mutations, including the calreticulin gene in addition to JAK2 and MPL, have led to a greater understanding of disease pathogenesis and set the stage for the advent of more sophisticated prognostic, diagnostic, and therapeutic strategies. In this paper we summarize recent studies describing the molecular basis of ET. We review the prognostic importance of establishing a 'true' ET diagnosis, as well as risk factors for the development of adverse outcomes including thrombosis, AML (2% risk at 15 years), and MF (9% risk at 15 years). Finally, we discuss the decision to initiate treatment and assess the quality of evidence supporting the use of established, available therapies as well as novel treatments. Special situations, such as pregnancy, familial ET, and extreme thrombocytosis will also be discussed.

Polycythemia vera (PV) and essential thrombocythemia (ET) are myeloproliferative neoplasms with variable risk of evolution into post-PV and post-ET myelofibrosis, from now on referred to as secondary myelofibrosis (SMF). No specific tools have been defined for risk stratification in SMF. To develop a prognostic model for predicting survival, we studied 685 JAK2, CALR, and MPL annotated patients with SMF. Median survival of the whole cohort was 9.3 years (95% CI: 8-not reached-NR-). Through penalized Cox regressions we identified negative predictors of survival and according to beta risk coefficients we assigned 2 points to hemoglobin level <11 g/dl, to circulating blasts ⩾3%, and to CALR-unmutated genotype, 1 point to platelet count <150 × 10 9 /l and to constitutional symptoms, and 0.15 points to any year of age. Myelofibrosis Secondary to PV and ET-Prognostic Model (MYSEC-PM) allocated SMF patients into four risk categories with different survival (P<0.0001): low (median survival NR; 133 patients), intermediate-1 (9.3 years, 95% CI: 8.1-NR; 245 patients), intermediate-2 (4.4 years, 95% CI: 3.2-7.9; 126 patients), and high risk (2 years, 95% CI: 1.7-3.9; 75 patients). Finally, we found that the MYSEC-PM represents the most appropriate tool for SMF decision-making to be used in clinical and trial settings.

Based on suggestive information from recent epidemiologic data and earlier retrospective studies, we revisited the effect of gender on survival in 1,494 patients with essential thrombocythemia (ET). The primary study population included 904 patients from the Mayo Clinic (median age 58 years; 65% females); risk distribution, according to the international prognostic score for ET (IPSET), was 23% high, 42% intermediate and 35% low. Multivariable analysis that included IPSET-relevant risk factors identified male sex (HR 1.6, 95% CI 1.3-2.0), age ≥60 years (HR 4.3, 95% CI 3.4-5.4) and leukocyte count ≥11 × 10(9)/L (HR 1.5, 95% CI 1.3-1.9) as independent predictors of shortened survival. These findings were confirmed by analysis of a separate cohort of 590 ET patients (65% females) from the University of Florence, Italy, with corresponding HRs (95% CI) of 1.6 (1.1-2.5), 4.6 (2.2-9.5) and 1.8 (1.1-2.8). The independent prognostic effect of gender was further corroborated by a separate multivariable analysis against IPSET risk categories; HR (95% CI) for the Mayo Clinic/Florence cohorts were 1.5/1.6 (1.2/1.1-1.8/2.5) for male sex, 6.8/7.5 (5.0/3.1-9.3/18.3) for IPSET high risk and 2.8/4.1 (2.1/1.8-3.8/9.5) for IPSET intermediate risk. Furthermore, the survival disadvantage in men was most apparent in IPSET high risk category and in patients older than 60 years. In both patient cohorts, thrombosis history garnered significance in univariate, but not in multivariable analysis. The observations from the current study suggest that women with ET live longer than their male counterparts and that gender might supersede thrombosis history as a risk variable for overall survival., (© 2017 Wiley Periodicals, Inc.)

The 2016 revised WHO criteria for the diagnosis of pre-fibrotic/early primary myelofibrosis (pre-PMF) require at least one of the following four borderline expressed minor clinical criteria: anemia, leukocytosis, elevated lactate dehydrogenase and splenomegaly. In this study, we evaluated the relative frequency of these four criteria in a group of 170 pre-PMF patients and compared them to 225 ET cases. More than 91% of pre-PMF cases showed one or more of these features required for diagnosis, by contrast with only 48% of ET patients. According to clinical data the cumulative risk of progression to advanced/overt PMF in pre-PMF was 36.9% after 15 years. After fitting cox regression models to analyze the impact of the minor criteria on overall survival, only leukocytosis remained as a significant predictor of survival in both pre-PMF and ET. Molecular characterization showed differences in survival in pre-PMF but not ET, with CALR being a more favorable mutation than JAK2. The different outcome of pre-PMF versus ET and associated molecular genetic data supports the concept of two different entities, rather than a continuum of the same disease. Although slightly less than 50% of ET patients also show one or more minor clinical criteria, accurate distinction between ET and pre-PMF is possible by following an integrated approach including histomorphological diagnosis and presence of minor clinical criteria., (© 2017 Wiley Periodicals, Inc.)

Myeloproliferative neoplasm (MPN) is a category in the World Health Organization classification of myeloid tumors. BCR-ABL1-negative MPN is a subcategory that includes primary myelofibrosis (MF), post-essential thrombocythemia MF, and post-polycythemia vera MF. These disorders are characterized by stem cell-derived clonal myeloproliferation. Clinically, these diseases present with anemia and splenomegaly and significant constitutional symptoms such as severe fatigue, symptoms associated with an enlarged spleen and liver, pruritus, fevers, night sweats, and bone pain. Multiple treatment options may provide symptom relief and improved survival; however, allogeneic stem cell transplantation (HCT) remains the only potentially curative option. The decision for a transplant is based on patient prognosis, age, comorbidities, and functional status. This review describes the recent data on various peritransplantation factors and their effect on outcomes of patients with MF and new therapeutic areas, such as the use and timing of Janus kinase inhibitors with HCT and gives overall conclusions from the available data in the published literature., (Copyright © 2017 The American Society for Blood and Marrow Transplantation. Published by Elsevier Inc. All rights reserved.)

The influence of driver mutations on leukaemic transformation was analysed in 1747 patients with polycythaemia vera or essential thrombocythaemia. With a median follow-up of 7·2 years, 349 patients died and 62 progressed to acute leukaemia or myelodysplastic syndrome. Taking death as a competing risk, CALR genotype was associated with a lower risk of transformation [subdistribution hazard ratio (SHR): 0·13, 95% confidence interval (CI): 0·2-0·9, P = 0·039], whereas JAK2 V617F showed borderline significance for higher risk (SHR: 2·05, 95% CI: 0·9-4·6, P = 0·09). Myelofibrotic transformation increased leukaemic risk, except in CALR-mutated patients. Next generation sequencing of 51 genes at the time of transformation showed additional mutations (median number: 3; range: 1-5) in 25 out of 29 (86%) assessable cases. Mutations (median: 1; range: 1-3) were detected in 67% of paired samples from the chronic phase. Leukaemia appeared in a JAK2 V617F negative clone in 17 (58%) cases, eleven of them being previously JAK2 V617F-positive. JAK2 V617F-mutated leukaemia was significantly associated with complex karyotype and acquisition of TP53 mutations, whereas EZH2 and RUNX1 mutations were more frequent in JAK2 V617F-negative leukaemia. Survival was longer in JAK2 V617F-unmutated leukaemia (343 days vs. 95 days, P = 0·003). In conclusion, CALR genotype is associated with a lower risk of leukaemic transformation. Leukaemia arising in a JAK2 V617F-negative clone is TP53 independent and shows better survival., (© 2017 John Wiley & Sons Ltd.)

Objective: Chronic myeloproliferative neoplasms (CMPNs) that include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF) are Philadelphia-negative malignancies characterized by a clonal proliferation of one or several lineages. The aim of this report was to determine the demographic features, disease characteristics, treatment strategies, and survival rates of patients with CMPNs in Turkey., Materials and Methods: Across all of Turkey, 9 centers were enrolled in the study. We retrospectively evaluated 708 CMPN patients' results including 390 with ET, 213 with PV, and 105 with PMF., Results: The JAK2V617F mutation was found positive in 86% of patients with PV, in 51.5% of patients with ET, and in 50.4% of patients with PMF. Thrombosis and bleeding at diagnosis occurred in 20.6% and 7.5% of PV patients, 15.1% and 9% of ET patients, and 9.5% and 10.4% of PMF patients, respectively. Six hundred and eight patients (85.9%) received cytoreductive therapy. The most commonly used drug was hydroxyurea (89.6%). Leukemic and fibrotic transformations occurred at rates of 0.6% and 13.2%. The estimated overall survival in PV, ET, and PMF patients was 89.7%, 85%, and 82.5% at 10 years, respectively. There were no significant differences between survival in ET, PV, and PMF patients at 10 years., Conclusion: Our patients' results are generally compatible with the literature findings, except for the relatively high survival rate in PMF patients. Hydroxyurea was the most commonly used cytoreductive therapy. Our study reflects the demographic features, patient characteristics, treatments, and survival rates of Turkish CMPN patients.

Philadelphia-negative classical myeloproliferative neoplasms (MPNs) include polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF). The 2016 revision of the WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues includes new criteria for the diagnosis of these disorders. Somatic mutations in the 3 driver genes, that is, JAK2 , CALR , and MPL , represent major diagnostic criteria in combination with hematologic and morphological abnormalities. PV is characterized by erythrocytosis with suppressed endogenous erythropoietin production, bone marrow panmyelosis, and JAK2 mutation. Thrombocytosis, bone marrow megakaryocytic proliferation, and presence of JAK2 , CALR , or MPL mutation are the main diagnostic criteria for ET. PMF is characterized by bone marrow megakaryocytic proliferation, reticulin and/or collagen fibrosis, and presence of JAK2 , CALR , or MPL mutation. Prefibrotic myelofibrosis represents an early phase of myelofibrosis, and is characterized by granulocytic/megakaryocytic proliferation and lack of reticulin fibrosis in the bone marrow. The genomic landscape of MPNs is more complex than initially thought and involves several mutant genes beyond the 3 drivers. Comutated, myeloid tumor-suppressor genes contribute to phenotypic variability, phenotypic shifts, and progression to more aggressive disorders. Patients with myeloid neoplasms are at variable risk of vascular complications, including arterial or venous thrombosis and bleeding. Current prognostic models are mainly based on clinical and hematologic parameters, but innovative models that include genetic data are being developed for both clinical and trial settings. In perspective, molecular profiling of MPNs might also allow for accurate evaluation and monitoring of response to innovative drugs that target the mutant clone., (© 2017 by The American Society of Hematology.)

There has been a major revolution in the management of patients with myeloproliferative neoplasms (MPN), and in particular those with myelofibrosis and extensive splenomegaly and symptomatic burden, after the introduction of the JAK1 and JAK2 inhibitor ruxolitinib. The drug also has been approved as second-line therapy for polycythemia vera (PV). However, the therapeutic armamentarium for MPN is still largely inadequate for coping with patients' major unmet needs, which include normalization of life span (myelofibrosis and some patients with PV), reduction of cardiovascular complications (mainly PV and essential thrombocythemia), prevention of hematological progression, and improved quality of life (all MPN). In fact, none of the available drugs has shown clear evidence of disease-modifying activity, even if some patients treated with interferon and ruxolitinib showed reduction of mutated allele burden, and ruxolitinib might extend survival of patients with higher-risk myelofibrosis. Raised awareness of the molecular abnormalities and cellular pathways involved in the pathogenesis of MPN is facilitating the development of clinical trials with novel target drugs, either alone or in combination with ruxolitinib. Although for most of these molecules a convincing preclinical rationale was provided, the results of early phase 1 and 2 clinical trials have been quite disappointing to date, and toxicities sometimes have been limiting. In this review, we critically illustrate the current landscape of novel therapies that are under evaluation for patients with MPN on the basis of current guidelines, patient risk stratification criteria, and previous experience, looking ahead to the chance of a cure for these disorders., (© 2017 by The American Society of Hematology.)

The unprecedented success of ruxolitinib in myelofibrosis (MF) has paved the way for the development of other Janus kinase (JAK) inhibitors and other agents representing diverse drug classes and mechanisms of action in myeloproliferative neoplasms (MPNs). In particular, the symptomatic benefits afforded by ruxolitinib have led to the recognition of "clinical improvement" in symptoms and the spleen in international consensus response criteria for MF. Ruxolitinib is also approved for the second-line treatment of polycythemia vera and is being developed for essential thrombocythemia. Appreciation of the universal role of activated JAK/signal transducer and activator of transcription (STAT) signaling in MPNs and improved understanding of the canonical and noncanonical actions of JAK2 have yielded a number of drug targets beyond JAK2 in MPNs, which form the basis for a number of ruxolitinib-based rational combinations that are being explored in MF. Other JAK inhibitors with the potential for significantly less myelosuppression or even improvement of anemia continue to be tested. Finally, agents with very distinct mechanisms of action, such as novel interferon formulations, antifibrotic agents, and telomerase inhibitors, are being pursued in polycythemia vera and MF, respectively. This article reviews the current landscape of clinical drug development in MPNs, focusing on the most promising agents and combinations., (Copyright © 2016 by the National Comprehensive Cancer Network.)

The nationwide statistical analysis of each disease of classical myeloproliferative neoplasm (MPN) in Korea has not been reported yet. To this end, we have analyzed incidence rates, survival rates and treatment pattern of polycythemia vera (PV), primary myelofibrosis (MF) and essential thrombocythemia (ET) using Korea National Cancer Incidence Database (KNCIDB) and Health Insurance Review and Assessment Service (HIRA) database. Between 2003 and 2011, a total of 4,342 new cases of MPN were reported to the KNCIDB. ET was the most common, followed by MF and PV. The crude incidence rates for PV, MF, and ET have increased during the period, reaching 0.40, 0.15, and 0.84 per 100,000, respectively. Five-year relative survival rate of all MPN patients was 89.3%, with lowest relative survival rate with MF (53.1%). The prevalence of each disease estimated from HIRA data also increased during the study period. Notably, ET was found to be most prevalent. The prescription rate of hydroxyurea and phlebotomy to PV, MF and ET patients remained constant over the period, and the prescription rate of hydroxyurea was higher in patients with age over 60 years. This is the first Korean nationwide statistics of MPN, using central registry data. This set of data can be utilized to compare the Korean MPN status to international data and guidelines., Competing Interests: The authors have no potential conflicts of interest to disclose.

Background: Acquired calreticulin (CALR) gene mutations are one of the molecular hallmarks of essential thrombocythemia (ET). It has been suggested that patients with ET with CALR mutations are associated with a distinct clinical phenotype., Patients and Methods: We evaluated the clinical and molecular features of 150 patients with ET followed over a period of 15 years. The screening for the presence of insertion/deletion mutations in CALR exon 9 was done with a fluorescent polymerase chain reaction/capillary electrophoresis procedure. Sanger sequencing of CALR exon 9 was used for the characterization of mutations and for the analysis of triple-negative patients., Results: CALR mutations were detected in 42 (28%) patients. The most common CALR mutations were type 1 and type 2, which were present in 11 (26.2%) and 20 (47.6%) patients, respectively. Additionally, 10 different small insertion/deletions (3 known and 7 new) were detected in 11 patients, resulting in an altered calreticulin C-terminal end. The clinical characteristics of all CALR+ patients with ET were in line with previously published data for this subset of patients., Conclusion: Our results showed that a wide range of different CALR mutations are associated with a distinct ET clinical phenotype that is associated with the male gender, younger age at diagnosis, higher platelet and lower leukocyte and erythrocyte counts and lower hemoglobin level, and a milder clinical course. The relatively high frequency of new insertion/deletion mutations indicate that the use of fluorescent polymerase chain reaction followed by capillary electrophoresis is the method of choice for the analysis of these defects., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Transformation to secondary myelofibrosis (MF) occurs as part of the natural history of polycythemia vera (PPV-MF) and essential thrombocythemia (PET-MF). Although primary (PMF) and secondary MF are considered similar diseases and managed similarly, there are few studies specifically focused on the latter. The aim of this study was to characterize the mutation landscape, and describe the main clinical correlates and prognostic implications of mutations, in a series of 359 patients with PPV-MF and PET-MF. Compared with PV and ET, the JAK2V617F and CALR mutated allele burden was significantly higher in PPV-MF and/or PET-MF, indicating a role for accumulation of mutated alleles in the process of transformation to MF. However, neither the allele burden nor the type of driver mutation influenced overall survival (OS), while absence of any driver mutation (triple negativity) was associated with significant reduction of OS in PET-MF, similar to PMF. Of the five interrogated subclonal mutations (ASXL1, EZH2, SRSF2, IDH1, and IDH2), that comprise a prognostically detrimental high molecular risk (HMR) category in PMF, only SRSF2 mutations were associated with reduced survival in PET-MF, and no additional mutation profile with prognostic relevance was highlighted. Overall, these data indicate that the molecular landscape of secondary forms of MF is different from PMF, suggesting that unknown mutational events might contribute to the progression from chronic phase disease to myelofibrosis. These findings also support more extended genotyping approaches aimed at identifying novel molecular abnormalities with prognostic relevance for patients with PPV-MF and PET-MF. Am. J. Hematol. 91:681-686, 2016. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Patients with essential thrombocythemia (ET) often suffer from neurological symptoms (NS) not ever resulting from previous thrombotic cerebral events (TCE). We reported NS occurred in 282 patients, in order to identify the factors influencing ET-related NS in the absence of TCE, and the response to therapy. Overall, 116 of 282 patients (41%) presented NS; 101 of them (87%) reported subjective transient and fluctuating NS, without concurrent TCE, which we defined as ET-related NS, by frequency: cephalalgia, chronic paresthesias, dizziness or hypotension, visual disturbances, and tinnitus. In univariate analysis, ET-related NS resulted more frequently in young people (P = 0.017) and in females (P = 0.025). We found a higher prevalence of JAK2V617F mutation in ET-related NS patients (P = 0.021). In multivariate analysis, gender (P = 0.024) and JAK2V617F mutation (P = 0.041) remained significantly associated with the development of ET-related NS, with a risk of about four times higher for JAK2V617F-mutated patients (OR = 3.75). Ninety-seven of 101 patients with ET-related NS received an antiplatelet (AP) agent at the time of NS, whereas only selected high-risk ET-related NS patients were treated with a cytoreductive drug, according to the published guidelines and similarly to patients without NS. We observed that only 32 of 97 (33%) patients with ET-related NS achieved a complete response after AP treatment. Among the 65 non-responder patients, 36 (55.4%) improved NS after the introduction of cytoreductive therapy; therefore, the addition of cytoreductive treatment should be considered in this setting., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

About 85% of patients with essential thrombocythemia (ET) harbor one of three driver mutations: JAK2, calreticulin (CALR), and MPL; the remaining ( ∼15%) are wild type for all three mutations and are referred to as being "triple negative." Furthermore, CALR mutations in ET are structurally classified as type 1/type 1-like or type 2/type 2-like variants. The objective of the current study was to examine the impact of CALR mutation variant stratified driver mutational status on overall (OS), myelofibrosis-free (MFFS), thrombosis-free, and leukemia-free survival (LFS) in ET; 495 patients (median age 58 years; 61% females) with ET were fully annotated for the their driver mutational status: 321 (65%) harbored JAK2, 109 (22%) CALR, and 12 (2%) MPL mutations and 11% were triple-negative. Among the 109 CALR-mutated cases, 52% were classified as type 1/type 1-like and 48% as type 2/type 2-like. In univariate analysis, triple-negative patients displayed the best and MPL mutated the worst OS (P = 0.007); however, the difference in OS was no longer apparent on multivariable analysis that included age and sex as covariates (P = 0.5). LFS was also similar among the different mutational groups (P = 0.6) whereas MFFS was significantly shorter in MPL-mutated patients on both univariate and multivariable analyses (age-adjusted P = 0.02; HR 7.9, 95% CI 2.0-31.5). Also in multivariable analysis that included thrombosis history, age, and cardiovascular risk factors, the presence of JAK2 or MPL mutations was independently associated with higher risk of thrombosis (P = 0.02; HR 1.9, 95% CI 1.1-3.4). In conclusion, driver mutational status in ET does not appear to influence overall or LFS, even after CALR variant stratification. However, the presence of MPL mutations might be associated with a higher risk of fibrotic transformation and the presence of JAK2/MPL mutations with higher risk of thrombosis., (© 2016 Wiley Periodicals, Inc.)

The current consensus on the diagnosis, prognosis, and treatment of essential thrombocythemia (ET) is based on experts' recommendations. However, several aspects of the diagnosis of, prognosis of, and therapy for ET are still controversial. The Delphi method was employed with an expert panel of members of the Spanish Group of Ph-negative Myeloproliferative Neoplasms in order to identify the degree of agreement on the diagnosis, prognosis, and treatment of ET. Nine leading experts selected a total of 41 clinical hematologists with well-known expertise in ET. An electronic questionnaire was used to collect the questions rated in a four-step scale. The questions were grouped into four blocks: diagnosis, risk stratification, goals of therapy, and treatment strategy. After the first round consisting of 80 questions, a second round including 14 additional questions focused on the recommendations advocated by experts of the European LeukemiaNet in 2011 was analyzed. The median and mean values for the first and second rounds were calculated. A summary of the conclusions considered as the most representative of each block of questions is presented. The Delphi method is a powerful instrument to address the current approaches and controversies surrounding ET.