![]() ![]() Both the SELECT-D and HOKUSAI-VTE Cancer studies evaluated the use of rivaroxaban and edoxaban, respectively, in randomised controlled trials for cancer-associated VTE, including lymphoma and multiple myeloma, with similar overall outcomes for both DOACs in comparison to low molecular weight heparin, the prior standard of care (Young et al., 2018). Subgroup analyses of the EINSTEIN-DVT (deep-vein thrombosis) and EINSTEIN-PE (pulmonary embolism) studies in patients with active and/or a history of cancer at the time of VTE demonstrated that rivaroxaban is as efficacious as standard therapy (VKA and enoxaparin) in preventing thrombosis in this cohort and has reduced bleeding complications (Prins et al., 2014). In the last five years, there has been a significant change in the use of direct oral anticoagulants (DOACs) in non-MPN associated VTE. Traditionally, vitamin K antagonists (VKA) have been the mainstay of anticoagulation for MPN-associated VTE and recent data suggest a high rate of recurrent VTE when they are discontinued in MPN patients (De Stefano et al., 2016). In particular, splanchnic vein thromboses are common in MPN and have high recurrence rates of between 15% and 20% over 10 years (Finazzi et al., 2018). Interestingly, MPN is strongly associated with the presence of thrombotic events in unusual sites such as abdominal veins (portal or hepatic vein) and cerebral venous sinus thrombosis. The prevalence of venous thromboembolic events at the time of diagnosis is higher in PV and ET (11–39% and 8–29%, respectively) compared to myelofibrosis (3–7%). There is also an increased risk of bleeding (Mahé et al., 2018). Patients with MPN may have both arterial and venous thromboembolism with an incidence of up to 10–30%. These act in addition to the well-recognised thrombotic risk factors including age (>60 years), obesity and smoking, which are key contributors to the risk of thrombosis and atherosclerosis in the general population. ( 2011) demonstrated a direct relationship between the presence of the JAK2 V617F mutation in MPN and C-reactive protein, whereby higher levels are associated with thrombotic events in MPN patients. High levels of inflammatory cytokines and adhesion molecules, circulating microparticles, enhanced thromboxane generation and/or endothelial activation ultimately will contribute to a pro-thrombotic state. Multiple factors underlie the complex pathogenesis of thrombosis in MPN including elevated blood viscosity, thrombocytosis and leucocytosis. Myeloproliferative neoplasms (MPN) are associated with an increased rate of venous thromboembolism (VTE), which is a major cause of morbidity and mortality, especially in the more indolent diseases of polycythaemia rubra vera (PV) and essential thrombocythaemia (ET) (Pearson, 2002 Tefferi & Barbui, 2017). ![]()
0 Comments
Leave a Reply. |