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.

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.

Primary cutaneous indolent B-cell lymphomas - a retrospective multicenter analysis and a review of literature.

Introduction: Primary cutaneous indolent B-cell lymphomas (PCBCLs) are not well characterized due to their rarity and indolent character.Methods: We retrospectively reviewed the data from 52 patients with primary cutaneous follicular lymphoma (PCFL) (n = 26), marginal zone lymphoma (PCMZL) (n = 25) or undefined PCBCL (n = 1) treated in 10 hematology centers in 1999-2019.Results: Patients characteristics and diagnostic approach: In almost half of the patients, pruritus or pain were present at diagnosis. The lesions were predominantly located on the head and trunk. The disease was present in a form of solitary infiltration or disseminated lesions with a similar frequency.Treatment details and outcomes: Surgery, radiotherapy, rituximab alone or combined with chemotherapy were applied as first-line treatment in 33%, 25%, 21% and 21% of patients, with complete response (CR) achieved by 94%, 83%, 50% and 70% of patients, respectively (p = 0.28). The median duration of response (DoR) was 65 months (95%CI 35-155).Survival: After the median follow-up time of 46 months (range: 3-225), the estimated 5-year overall survival (OS) and progression-free survival (PFS) were 93% and 54%, respectively.Discussion: Clinical presentation was largely consistent with the literature data, however, we observed some differences, including higher predilection to affect upper extremities (25%) and more frequent multifocal appearance in PCFCL (64%) and unifocal in PCMZL (70%).A high proportion of patients with indolent PCBCL achieved CR after the first-line therapy (77%), regardless of treatment mode. We did not find any impact of clinical features on treatment outcomes.Conclusions: All treatment modalities resulted in a high overall response rate. Surgery and/or radiotherapy are the optimal therapeutic options for patients with localized disease. The decision to treat systemically should rather be limited to the generalized form of the disease. High response rate, long duration of remission and excellent long-term survival confirm the truly indolent character of PCFCL and PCMZL.