How to manage anticoagulation for cancer-associated thrombosis and atrial fibrillation in cancer

Cancer associated thrombosis (CAT) is the second leading cause of death in oncologic patients and includes both venous thromboembolism (VTE) and arterial thrombotic events (ATE). In addition, cancer patients have an increased risk of developing atrial fibrillation (AF), which represents an additional risk factor for systemic thromboembolism in these patients. Both CAT and AF may be the first presentation of the oncologic disease or develop because of chemotherapy or radiotherapy. The management of the anticoagulation in cancer patients with CAT or AF is challenging, and data on these patients are lacking in specific settings/situations. Low molecular weight heparins (LMWHs) and direct oral anticoagulants (DOACs) represent the preferred treatment strategies in CAT, and DOACs in cancer patients with AF. However, the possible drug-drug interactions of DOACs and the bleeding risks in thrombocytopenic patients should be considered. The use of vitamin K antagonists (VKAs) in cancer patients with CAT or AF is challenging because of the unpredictable therapeutic response and high bleeding risk in patients with active disease who are undergoing chemotherapy and who may experience thrombocytopenia and/or changes in renal or hepatic function and, according to the recent guidelines, it is limited to specific situations (i.e. severe renal insufficiency, AF associated with prosthetic mechanical valves and severe mitral stenosis). A careful evaluation of the antithrombotic strategy with the best efficacy/safety ratio (in terms of doses or drugs) is always needed in cancer patients and anticoagulation for CAT and AF should be tailored individually. An ongoing consultation of oncologists/hematologists with cardiologists and coagulation experts in a multidisciplinary approach, with a periodic re-assessment of the benefit/risk ratio of anticoagulation with changes in cancer status/advancement and treatment plans is needed.