Real-world Data on Treatment Patterns and Bleeding in Cancer-associated Thrombosis: Data from the TROLL Registry.

International guidelines are increasingly recommending direct oral anticoagulants (DOACs) as the first-line treatment for cancer-associated thrombosis (CAT). However, data regarding treatment patterns and adherence to guidelines in patients with CAT are scarce.  This study aimed to explore anticoagulant treatment patterns in patients with CAT and to calculate the incidence rates of bleeding events.  Patients ≥18 years with active cancer and a first-time venous thromboembolism between 2005 and 2020 were identified through the Venous hrombosis egistry in Østf d Hospita . Outcome measures were patterns of anticoagulant treatment during the study period and bleeding events. We calculated overall incidence rates per 100 person-years and 6- and 12-month cumulative incidence of major and clinically relevant nonmajor bleeding (CRNMB) during anticoagulant treatment.  Median age of 842 CAT patients at the time of thrombosis was 69 years (interquartile range 61-77), and 443 (52.6%) were men. In total, 526 patients (62.5%) had pulmonary embolism and 255 (30.3%) had deep vein thrombosis. Low molecular weight heparin (LMWH) was prescribed to 713 (85.8%) patients, whereas 64 (7.7%) received DOACs and 54 (6.5%) received vitamin K antagonists as the initial anticoagulant treatment. Prescription of DOACs as initial treatment increased from 3.0% in 2013/2014 to 18.0% in 2019/2020. The incidence rate of major bleeding was 6.9 (95% confidence interval [CI] 5.2-9.2) and 10.1 (95% CI 8.0-12.9) in CRNMB.  Most patients were treated with LMWH. However, a gradual shift in treatment toward DOACs was observed. Overall, bleeding complications were rare and comparable to those reported in randomized trials.