ß-Hydroxybutyrate suppresses colorectal cancer.

Colorectal cancer (CRC) is among the most frequent forms of cancer, and new strategies for its prevention and therapy are urgently needed1. Here we identify a metabolite signalling pathway that provides actionable insights towards this goal. We perform a dietary screen in autochthonous animal models of CRC and find that ketogenic diets exhibit a strong tumour-inhibitory effect. These properties of ketogenic diets are recapitulated by the ketone body ß-hydroxybutyrate (BHB), which reduces the proliferation of colonic crypt cells and potently suppresses intestinal tumour growth. We find that BHB acts through the surface receptor Hcar2 and induces the transcriptional regulator Hopx, thereby altering gene expression and inhibiting cell proliferation. Cancer organoid assays and single-cell RNA sequencing of biopsies from patients with CRC provide evidence that elevated BHB levels and active HOPX are associated with reduced intestinal epithelial proliferation in humans. This study thus identifies a BHB-triggered pathway regulating intestinal tumorigenesis and indicates that oral or systemic interventions with a single metabolite may complement current prevention and treatment strategies for CRC.

Characteristics and outcomes of patients with lymphoma who developed therapy-related acute myeloid leukemia or myelodysplastic syndrome - a retrospective analysis of the Polish Adult Leukemia Group.

Introduction: Enhancing lymphoma outcomes increases the risk of therapy-related neoplasms such as acute myeloid leukemia (t-AML) and myelodysplastic syndrome (t-MDS). Material and methods: Our study, conducted at seven Polish hematology centers between 2011 and 2018, explores clinical features, outcomes, and prognostic factors of t-AML and t-MDS arising after initial lymphoid neoplasms. Results: The analysis included 57 patients of median age 65 with t-MDS (n = 38) and t-AML (n = 19). The median time to the onset of t-MDS/AML was 58.7 months. The median overall survival (OS) was 16.1 months. The presence of unfavorable cytogenetics and molecular risk factors (HR 2.88, 95% CI: 1.29-6.42, p = 0.009), hemoglobin level (HR 0.79, 95% CI: 0.65-0.95, p = 0.01) and platelets (HR 0.99, 95% CI: 0.99-0.9996, p = 0.03) were independent prognostic factors influencing OS. Therapy- related myelodysplastic syndrome/acute myeloid leukemia after lymphoma treatment is associated with a dismal prognosis mainly due to poor cytogenetic risk. Conclusions: Anemia and thrombocytopenia may indicate more severe impairment of bone marrow function, resulting in further inferior treatment outcomes.

Validation of thrombotic risk factors in 1381 patients with essential thrombocythaemia: A multicentre retrospective real-life study.

Thrombosis and haemorrhage are frequent in patients with essential thrombocythaemia (ET). The 2016 revised International Prognostic Score for Thrombosis in Essential Thrombocythaemia-thrombosis (r-IPSET-t) score stratifies patients into very-low- (VLR), low- (LR), intermediate- (IR) and high-risk (HR) groups. We validated the r-IPSET-t in the biggest population of patients with ET (n = 1381) to date and found it to be a better fit than the earlier IPSET-t score. With an average follow-up of 87.7 months, there were 0.578 thrombotic events/person-year and 0.286 bleeding events/person-year after diagnosis. The 10-year thrombosis-free survival was 88% and 99% for the r-IPSET-t LR and VLR groups (p < 0.001). Cytoreduction was a thrombotic risk factor in younger patients (aged <60 years, hazard ratio 9.49, p = 0.026; aged ≥60 years, hazard ratio 1.04, p = 0.93). In multivariable Cox regression analysis, anti-aggregation after diagnosis was protective for thrombosis (hazard ratio 0.31, p = 0.005) but a risk factor for major bleeding (hazard ratio 10.56, p = 0.021). Of the IPSET-t HR and LR groups, 132/780 and 249/301 were re-classified as LR and VLR respectively (p < 0.001). The European LeukemiaNET (ELN) does not recommend aspirin for VLR patients but in this real-life analysis 83.1% of VLR patients received it. Our results validate the r-IPSET-t score as more predictive for thrombosis than the ELN-recommended IPSET-t and raise concerns about unnecessary cytoreductive and anti-aggregative therapy.

Longitudinal changes in COVID-19 vaccination intent among South African adults: evidence from the NIDS-CRAM panel survey, February to May 2021.

BACKGROUND: COVID-19 vaccine hesitancy has threatened the ability of many countries worldwide to contain the pandemic. Given the severe impact of the pandemic in South Africa and disruptions to the roll-out of the vaccine in early 2021, slower-than-expected uptake is a pressing public health challenge in the country. We examined longitudinal changes in COVID-19 vaccination intent among South African adults, as well as determinants of intent to receive a vaccine. METHODS: We used longitudinal data from Wave 4 (February/March 2021) and Wave 5 (April/May 2021) of the National Income Dynamics Study: Coronavirus Rapid Mobile Survey (NIDS-CRAM), a national and broadly representative panel survey of adults in South Africa. We conducted cross-sectional analyses on aggregate and between-group variation in vaccination intent, examined individual-level changes between waves, and modeled demographic predictors of intent. RESULTS: We analysed data for 5629 (Wave 4; 48% male, mean age 41.5 years) and 5862 (Wave 5; 48% male, mean age 41.6 years) respondents. Willingness to get a COVID-19 vaccine significantly increased from 70.8% (95% CI: 68.5-73.1) in Wave 4 to 76.1% (95% CI: 74.2-77.8) in Wave 5. Individual-level analyses indicated that only 6.6% of respondents remained strongly hesitant between survey waves. Although respondents aged 18-24 years were 8.5 percentage points more likely to report hesitancy, hesitant respondents in this group were 5.6 percentage points more likely to change their minds by Wave 5. Concerns about rushed testing and safety of the vaccines were frequent and strongly-held reasons for hesitancy. CONCLUSIONS: Willingness to receive a COVID-19 vaccine has increased among adults in South Africa, and those who were entrenched in their reluctance make up a small proportion of the country's population. Younger adults, those in formal housing, and those who trusted COVID-19 information on social media were more likely to be hesitant. Given that stated vaccination intent may not translate into behaviour, our finding that three-quarters of the population were willing to accept the vaccine may reflect an upper bound. Vaccination promotion campaigns should continue to frame vaccine acceptance as the norm and tailor strategies to different demographic groups.

Do myeloproliferative neoplasms and multiple myeloma share the same genetic susceptibility loci?

Myeloproliferative neoplasms (MPNs) are a group of diseases that cause myeloid hematopoietic cells to overproliferate. Epidemiological and familial studies suggest that genetic factors contribute to the risk of developing MPN, but the genetic susceptibility of MPN is still not well known. Indeed, only few loci are known to have a clear role in the predisposition to this disease. Some studies reported a diagnosis of MPNs and multiple myeloma (MM) in the same patients, but the biological causes are still unclear. We tested the hypothesis that the two diseases share at least partly the same genetic risk loci. In the context of a European multicenter study with 460 cases and 880 controls, we analyzed the effect of the known MM risk loci, individually and in a polygenic risk score (PRS). The most significant result was obtained among patients with chronic myeloid leukemia (CML) for PS0RS1C1-rs2285803, which showed to be associated with an increased risk (OR = 3.28, 95% CI 1.79-6.02, P = .00012, P = .00276 when taking into account multiple testing). Additionally, the PRS showed an association with MPN risk when comparing the last with the first quartile of the PRS (OR = 2.39, 95% CI 1.64-3.48, P = 5.98 × 10-6 ). In conclusion, our results suggest a potential common genetic background between MPN and MM, which needs to be further investigated.

Azacitidine for relapse of acute myeloid leukemia or myelodysplastic syndrome after allogeneic hematopoietic stem cell transplantation, multicenter PALG analysis.

OBJECTIVES: Relapse of myelodysplastic syndromes (MDS) or acute myeloid leukemia (AML) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) belongs to the major causes of treatment failure. METHODS: Retrospective multicenter analysis of patients diagnosed with AML or MDS who had hematological relapse after allo-HSCT and were treated with azacitidine for this indication. RESULTS: Twenty-three patients receiving azacitidine as the first treatment of relapse (Group_1) and 8 patients receiving azacitidine after other treatment of relapse (Group_2) were included. There were 68% males, median age at initiation of azacitidine was 53 years (15-66). Median time to relapse was 3.5 months and 6.3 months in Group_1 and Group_2, respectively; median time from relapse to azacitidine 0.2 and 2.3 months. Azacitidine 75 mg/m2 , days 1-7, was administered in 78% and 75% of patients in Group_1 and Group_2, concomitant DLI in 48% and 50%. With median follow-up of 4.7 and 13.6 months, the median overall survival was 5.9 and 9.5 months. 17% and 37.5% patients proceeded to salvage allo-HSCT, with median OS of 11.6 months and not reached respectively. CONCLUSIONS: Azacitidine treatment for hematological relapse is associated with poor outcome; nevertheless, a proportion of patients may benefit from it, including patients receiving subsequent salvage allo-HSCT.

The risk of thrombosis in essential thrombocythemia is associated with the type of CALR mutation: A multicentre collaborative study.

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.

Addition of cladribine to the standard induction treatment improves outcomes in a subset of elderly acute myeloid leukemia patients. Results of a randomized Polish Adult Leukemia Group (PALG) phase II trial.

Intensive induction chemotherapy using anthracycline and cytarabine backbone is considered the most effective upfront therapy in physically fit older patients with acute myeloid leukemia (AML). However, outcomes of the standard induction in elderly AML are inferior to those observed in younger patients, and they are still unsatisfactory. As addition of cladribine to the standard induction therapy is known to improve outcome in younger AML patients. The present randomized phase II study compares efficacy and toxicity of the DAC (daunorubicin plus cytarabine plus cladribine) regimen with the standard DA (daunorubicin plus cytarabine) regimen in the newly diagnosed AML patients over 60 years of age. A total of 171 patients were enrolled in the study (DA, 86; DAC, 85). A trend toward higher complete remission (CR) was observed in the DAC arm compared to the DA arm (44% vs. 34%; P = .19), which did not lead to improved median overall survival, which in the case of the DAC group was 8.6 months compared to in 9.1 months in the DA group (P = .64). However, DAC appeared to be superior in the group of patients aged 60-65 (CR rate: DAC 51% vs. DA 29%; P = .02). What is more, a subgroup of patients, with good and intermediate karyotypes, benefited from addition of cladribine also in terms of overall survival (P = .02). No differences in hematological and nonhematological toxicity between the DA and DAC regimens were observed.

Aluminium-adjuvanted vaccines--a review of the current state of knowledge.

Since decades aluminium formulations such as aluminium hydroxide and aluminium phosphate are widely used as adjuvants in vaccines for human use. They increase immune response induced by the vaccine antigens by mechanisms eg. a depot effect at the injection site, activation of the complement and stimulation of the macrophages. Many studies, both case control ones and those performed in vivo on animal models, confirmed the safety of aluminium adjuvants even in vaccinated infants and children. Although some of the aluminium-adjuvanted vaccines have certain limitations such as no Th1 reactivity and low stability at temperatures below 2ºC, its easy use, safety profile and low manufacturing costs confirm its suitability.

Thiomersal-containing vaccines - a review of the current state of knowledge.

Thiomersal is an organomercury compound known for its antiseptic and antifungal properties and used as an antibacterial agent in pharmaceutical products, including vaccines and other injectable biological products. In recent years, concerns about the possible link between immunization with thiomersal-containing vaccines and autism development have grown. Many case-control and cohort studies have been conducted on a number of populations, and none of them have confirmed the hypothetical relation between thiomersal and increased risk of autism spectrum disorders (ASDs) development. It is also confirmed by the fact, that since 1999, number of thiomersal-containing vaccines used worldwide is decreasing year by year, while the prevalence of ASDs cases is rising. There are no contraindications to the use of vaccines with thiomersal in infants, children and non-pregnant women. The risk of serious complications associated with the development of diseases in unvaccinated individuals far outweighs the potential risk of adverse consequences associated with immunization with thiomersal-containing vaccines.

"Do not inject our babies": a social listening analysis of public opinion about authorizing pediatric COVID-19 vaccines.

Designing effective childhood vaccination counseling guidelines, public health campaigns, and school-entry mandates requires a nuanced understanding of the information ecology in which parents make vaccination decisions. However, evidence is lacking on how best to "catch the signal" about the public's attitudes, beliefs, and misperceptions. In this study, we characterize public sentiment and discourse about vaccinating children against SARS-CoV-2 with mRNA vaccines to identify prevalent concerns about the vaccine and to understand anti-vaccine rhetorical strategies. We applied computational topic modeling to 149 897 comments submitted to regulations.gov in October 2021 and February 2022 regarding the Food and Drug Administration's Vaccines and Related Biological Products Advisory Committee's emergency use authorization of the COVID-19 vaccines for children. We used a latent Dirichlet allocation topic modeling algorithm to generate topics and then used iterative thematic and discursive analysis to identify relevant domains, themes, and rhetorical strategies. Three domains emerged: (1) specific concerns about the COVID-19 vaccines; (2) foundational beliefs shaping vaccine attitudes; and (3) rhetorical strategies deployed in anti-vaccine arguments. Computational social listening approaches can contribute to misinformation surveillance and evidence-based guidelines for vaccine counseling and public health promotion campaigns.

Safety considerations for drugs newly approved for treating acute myeloid leukemia.

INTRODUCTION: Acute myeloid leukemia (AML) is typically characterized by a poor prognosis, mainly due to the median age at diagnosis. Until recently, treatment options were limited to intensive chemotherapy (IC) for young patients or hypomethylating agents for those ineligible for IC. Since 2017, nine molecules were registered for newly-diagnosed AML: midostaurin, gilteritinib, quizartinib, enasidenib, ivosidenib, gemtuzumab ozogamicin, CPX-351, glasdegib, and venetoclax. AREAS COVERED: The review examines the safety profile of these drugs and their interactions with other agents used in supportive care. The PubMed and Google Scholar databases were searched for articles in English concerning new agents in AML from 2017 until 2023. Further relevant publications were obtained by reviewing the prescribing information and Food and Drug Administration (FDA) data. EXPERT OPINION: The therapeutic spectrum in AML has broadened over several years and can also improve outcomes in older patients. However, in addition to their well-known cytotoxic activity, new molecules cause several unique, off-target toxicities. Also, potential drug-drug interactions (DDI) should be taken into consideration when choosing optimal first-line therapy; this remains a challenge in clinical practice.

Sociodemographic disparities in prostate cancer imaging.

Imaging is central to the diagnosis, staging, treatment planning, and monitoring of prostate cancer (PCa). Unequal access to new imaging techniques may directly contribute to gaps in PCa treatment and outcome. Thus, identifying disparities in PCa diagnosis and treatment are centrla to informing strategies to promote equitable cancer care. This review examines the existing evidence regarding clinical and sociodemographic factors associated with disparities in imaging utilization and treatment for PCa. Major areas of disparities identified include healthcare and research access. Sociodemographic disparities are present in screening and diagnosis; Black patients are consistently less likely to receive both prostate multiparametric MRI and timely molecular imaging used to evaluate for biochemical recurrence. Regional variation in appropriate and inappropriate diagnostic imaging also contributes to corresponding differences in outcomes, especially between urban and rural settings. Delays in PCa imaging and diagnosis also delay definitive treatment or placement on active surveillance, with prominent differences by race and measures of social advantage Recognition of these disparities in PCa imaging and treatment can reinforce actions to improve equitable access to patients affected by PCa. Identifying modifiable steps in the PCa diagnosis, staging, and treatment workflow may inform interventions to bridge gaps in cancer outcome.

No advantage of antimicrobial prophylaxis in AML/MDS/CMML patients treated with azacitidine-a prospective multicenter study by the Polish Adult Leukemia Group.

Introduction: Infections represent one of the most frequent causes of death of higher-risk MDS patients, as reported previously also by our group. Azacitidine Infection Risk Model (AIR), based on red blood cell (RBC) transfusion dependency, neutropenia <0.8 × 109/L, platelet count <50 × 109/L, albumin <35g/L, and ECOG performance status ≥2 has been proposed based on the retrospective data to estimate the risk of infection in azacitidine treated patients. Methods: The prospective non-intervention study aimed to identify factors predisposing to infection, validate the AIR score, and assess the impact of antimicrobial prophylaxis on the outcome of azacitidine-treated MDS/AML and CMML patients. Results: We collected data on 307 patients, 57.6 % males, treated with azacitidine: AML (37.8%), MDS (55.0%), and CMML (7.1%). The median age at azacitidine treatment commencement was 71 (range, 18-95) years. 200 (65%) patients were assigned to higher risk AIR group. Antibacterial, antifungal, and antiviral prophylaxis was used in 66.0%, 29.3%, and 25.7% of patients, respectively. In total, 169 infectious episodes (IE) were recorded in 118 (38.4%) patients within the first three azacitidine cycles. In a multivariate analysis ECOG status, RBC transfusion dependency, IPSS-R score, and CRP concentration were statistically significant for infection development (p < 0.05). The occurrence of infection within the first three azacitidine cycles was significantly higher in the higher risk AIR group - 47.0% than in lower risk 22.4% (odds ratio (OR) 3.06; 95% CI 1.82-5.30, p < 0.05). Administration of antimicrobial prophylaxis did not have a significant impact on all-infection occurrence in multivariate analysis: antibacterial prophylaxis (OR 0.93; 0.41-2.05, p = 0.87), antifungal OR 1.24 (0.54-2.85) (p = 0.59), antiviral OR 1.24 (0.53-2.82) (p = 0.60). Discussion: The AIR Model effectively discriminates infection-risk patients during azacitidine treatment. Antimicrobial prophylaxis does not decrease the infection rate.

The NUDGE Framework: Application to Address Behavioral Barriers to Antiretroviral Therapy in Adolescents Living With HIV in Eswatini.

Behavioral economics offers a unique opportunity to understand the social, cognitive, and psychological nuances that may influence health behavior. The purpose of this article is to demonstrate the application of NUDGE, a novel behavioral economics and design thinking framework, to address barriers to antiretroviral therapy adherence among adolescents living with HIV in eSwatini. NUDGE comprises five steps: (1) Narrow the focus to a specific target behavior, (2) Understand the context of the behavior through inquiry, (3) Discover behavioral insights related to the target behavior, (4) Generate intervention design features to address behavioral barriers to the target behavior, and (5) Evaluate the design features through iterative pilot testing. This article demonstrates the application of the Discover and Generate steps using qualitative data. In showing the utility of the NUDGE framework, we provide a practical tool for creating interventions informed by behavioral insights.

Management and outcome of patients with chronic myeloid leukemia in blast phase in the tyrosine kinase inhibitor era - analysis of the European LeukemiaNet Blast Phase Registry.

Blast phase (BP) of chronic myeloid leukemia (CML) still represents an unmet clinical need with a dismal prognosis. Due to the rarity of the condition and the heterogeneity of the biology and clinical presentation, prospective trials and concise treatment recommendations are lacking. Here we present the analysis of the European LeukemiaNet Blast Phase Registry, an international collection of the clinical presentation, treatment and outcome of blast phases which had been diagnosed in CML patients after 2015. Data reveal the expected heterogeneity of the entity, lacking a clear treatment standard. Outcomes remain dismal, with a median overall survival of 23.8 months (median follow up 27.8 months). Allogeneic stem cell transplantation (alloSCT) increases the rate of deep molecular responses. De novo BP and BP evolving from a previous CML do show slightly different features, suggesting a different biology between the two entities. Data show that outside clinical trials and in a real-world setting treatment of blast phase is individualized according to disease- and patient-related characteristics, with the aim of blast clearance prior to allogeneic stem cell transplantation. AlloSCT should be offered to all patients eligible for this procedure.

Experimental drugs in clinical trials for acute myeloid leukemia: innovations, trends, and opportunities.

INTRODUCTION: Acute myeloid leukemia (AML) is a heterogeneous disease characterized by many cytogenetic and molecular alterations. Due to better knowledge of the molecular basis of AML, many targeted therapies have been introduced and registered, e.g. FMS-like tyrosine kinase 3 inhibitors, isocitrate dehydrogenase 1/2 mutation inhibitors, and Bcl-2 inhibitor. Despite that, the cure for AML remains an unmet clinical need in most patients. AREAS COVERED: The review aims to present new, not yet registered drugs for AML. We searched the English literature for articles concerning AML, targeted drugs, menin inhibitors, DOT1L, BET, IDH inhibitors, FLT3, hedgehog inhibitors, Polo-like kinase inhibitors, RNA splicing, and immune therapies via PubMed. Publications from January 2000 to August 2022 were scrutinized. Additional relevant publications were obtained by reviewing the references from the chosen articles and Google search. Conference proceedings from the previous 5 years of The American Society of Hematology, the European Hematology Association, and the American Society of Clinical Oncology were searched manually. Additional relevant publications were obtained by reviewing the references. EXPERT OPINION: For several years, the therapeutic approach in AML has become more individualized. Novel groups of drugs give hope for greater curability. High response rates have agents that restore the activity of the p53 protein. In addition, agents that work independently of a particular mutation seem promising for AML without any known mutation.

Effects Of An Employee COVID-19 Vaccination Mandate At A Long-Term Care Network.

We assessed COVID-19 vaccination and employment status among employees of a long-term care network that announced an employee vaccination mandate on July 29, 2021. The day before the announcement, 1,208 employees were unvaccinated; of these workers, 56.2 percent subsequently were vaccinated, whereas 20.9 percent (3.7 percent of active employees) were terminated because of noncompliance with the mandate.

Dear Pandemic: A topic modeling analysis of COVID-19 information needs among readers of an online science communication campaign.

BACKGROUND: The COVID-19 pandemic was accompanied by an "infodemic"-an overwhelming excess of accurate, inaccurate, and uncertain information. The social media-based science communication campaign Dear Pandemic was established to address the COVID-19 infodemic, in part by soliciting submissions from readers to an online question box. Our study characterized the information needs of Dear Pandemic's readers by identifying themes and longitudinal trends among question box submissions. METHODS: We conducted a retrospective analysis of questions submitted from August 24, 2020, to August 24, 2021. We used Latent Dirichlet Allocation topic modeling to identify 25 topics among the submissions, then used thematic analysis to interpret the topics based on their top words and submissions. We used t-Distributed Stochastic Neighbor Embedding to visualize the relationship between topics, and we used generalized additive models to describe trends in topic prevalence over time. RESULTS: We analyzed 3839 submissions, 90% from United States-based readers. We classified the 25 topics into 6 overarching themes: 'Scientific and Medical Basis of COVID-19,' 'COVID-19 Vaccine,' 'COVID-19 Mitigation Strategies,' 'Society and Institutions,' 'Family and Personal Relationships,' and 'Navigating the COVID-19 Infodemic.' Trends in topics about viral variants, vaccination, COVID-19 mitigation strategies, and children aligned with the news cycle and reflected the anticipation of future events. Over time, vaccine-related submissions became increasingly related to those surrounding social interaction. CONCLUSIONS: Question box submissions represented distinct themes that varied in prominence over time. Dear Pandemic's readers sought information that would not only clarify novel scientific concepts, but would also be timely and practical to their personal lives. Our question box format and topic modeling approach offers science communicators a robust methodology for tracking, understanding, and responding to the information needs of online audiences.

Prediction of major bleeding events in 1381 patients with essential thrombocythemia.

The goal of therapy in essential thrombocythemia (ET) is reducing thrombotic risk. No algorithm to predict hemorrhage risk exists. The impact ofanti-platelet, cytoreductive and anticoagulation therapies on risk of major bleeding (MB) was evaluated. MB events were retrospectively analyzed in 1381 ET from 10 European centers. There were 0.286 MB events/person-year. Neither the International Thrombosis Prognostic Score for thrombosis in essential thrombocythemia (IPSET-t) nor the revised IPSET-t (r-IPSET-t) was predictive for hemorrhage-free survival at 10 years (p = 0.092 vs p = 0.1). Ageand leukocyte count were MB risk factors, while low hemoglobin was protective. For ET with extreme thrombocytosis (ExtT) and leukocytosis cytoreduction was not protective. MB were more frequent in ET with ExtT who received anticoagulation. Antiplatelet therapy was not, while anticoagulation was a risk factor for MB (HR 3.05, p = 0.016, CI 1.23-7.56), in particular vitamin K antagonists (22.6% of those treated had a MB event, HR 2.96, p = 0.004, CI 1.41-6.22). Survival at 10 years was associated with hemorrhage (OR 2.54, p < 0.001) but not thrombosis (HR 0.95, p = 0.829). Hemorrhage has a higher risk of mortality than thrombosis. Improved risk stratification for MB is necessary. The choice of anticoagulation, cytoreduction and antiplatelet therapies is an important area of research in ET.