Venous Thromboembolism in Hematologic Malignancies: Incidence, Risk Factors, and the Role of Direct Oral Anticoagulants

Thrombotic events, particularly venous thromboembolism (VTE), are a significant source of morbidity and mortality among patients with hematologic malignancies. These patients face unique challenges due to treatment-related complications such as thrombocytopenia, coagulopathy, and heightened bleeding risk. Traditionally managed with low molecular weight heparin (LMWH), the advent of direct oral anticoagulants (DOACs) has introduced new opportunities for both prophylaxis and treatment of cancer-associated thrombosis (CAT). This narrative review explores the disease-specific thrombotic risk across hematologic malignancies and critically evaluates the current evidence supporting the use of DOACs in this setting. While emerging data suggest DOACs are effective and safe for VTE treatment and secondary prophylaxis, although with a higher incidence of clinically relevant non-major bleeding in some studies, their role in primary prophylaxis remains under investigation and is currently limited by insufficient disease-specific data. Laboratory monitoring may be warranted in the presence of anti-cancer treatment-DOACs interactions or unexpected clinical events. The utility of DOACs is particularly constrained in thrombocytopenic patients, where bleeding risks are heightened and evidence remains limited. Overall, this review highlights the need for robust, prospective, disease-specific trials to define optimal anticoagulation strategies in oncohematologic patients and refine clinical decision-making in this complex and high-risk population.