Treatment and prevention of cancer-associated thrombosis in the Netherlands: A national survey

Background: In the recent years, numerous studies on the optimal treatment and prevention of cancer-associated venous thromboembolism (VTE) have been published, leading to updated (inter)national guidelines. These include direct oral anticoagulants (DOACs) as the first-line treatment agent in general and the recommendation of pri-mary thromboprophylaxis in selected ambulatory patients. Objectives: The objective of this study was to evaluate the clinical practice regarding treatment and prevention of VTE in patients with cancer in the Netherlands and practice variation among different specialties. Methods: An online survey was conducted between December 2021, and June 2022, among Dutch physicians (oncologists, hematologists, vascular medicine specialists, acute internal medicine specialists, and pulmonologists) treating patients with cancer, in which we explored the treatment of choice for cancer-associated VTE, the use of VTE risk stratification tools, and primary thromboprophylaxis. Results: A total of 222 physicians participated, of whom the majority (81%) used DOACs as a first-line agent for treating cancer-associated VTE. The treatment varied between the following specialties: hematologists and acute internal medicine specialists more often prescribed low-molecular-weight heparin than physicians of the other specialties (OR, 0.32; 95% CI, 0.13-0.80). The minimum duration of anticoagulant treatment was usually 3 to 6 months (87%), and treatment was extended when the malignancy was still active (98%). Regarding the prevention of cancer-associated VTE, no risk stratification tool was used. Three quarters of respondents never prescribed thromboprophylaxis to ambulatory patients, mostly because the thrombosis risk was not perceived high enough to justify prophylaxis. Conclusion: Dutch physicians largely adhere to the updated guidelines regarding the treatment of cancer-associated VTE but less to the recommendations for its prevention.