Therapeutic Anticoagulation in Patients with Primary Brain Tumors or Secondary Brain Metastasis

Patients with primary or metastatic brain tumors are at increased risk of developing venous thromboses. However, the potential benefit of therapeutic anticoagulation in these patients must be weighed against the deadly complication of intracranial hemorrhage. In this review, we summarize available evidence and recent studies of intracranial bleeding risks in primary and metastatic tumors and the impact of therapeutic anticoagulation. We find that for the majority of primary and treated metastatic brain tumors, the risk of spontaneous bleeding is acceptable and not further increased by careful therapeutic anticoagulation with low molecular weight heparin or direct oral anticoagulants, although thrombocytopenia (platelet count less than 50,000/μL) and other coagulopathies are relative contraindications. Patients with brain metastasis from melanoma, renal cell carcinoma, choriocarcinoma, thyroid carcinoma, and hepatocellular carcinoma have a higher tendency to bleed spontaneously than noted in patients with other malignancies, and thus warrant routine brain imaging and alternative strategies such as inferior vena cava filter placement in the acute setting of venous thromboembolism before consideration of therapeutic anticoagulation.

Malignant gliomas are associated with increased risks of both venous thromboses and intracranial hemorrhage, but the additional bleeding risk associated with therapeutic anticoagulation appears acceptable, especially after treatment of primary tumors. Most patients with treated brain metastasis have a low risk of intracranial hemorrhage associated with therapeutic anticoagulation, and low molecular weight heparin is currently the preferred agent of choice. Patients with untreated brain metastasis from melanoma, renal cell carcinoma, thyroid cancer, choriocarcinoma, and hepatocellular carcinoma have a higher propensity for spontaneous intracranial bleeding, and systemic anticoagulation may be contraindicated in the acute setting of venous thromboembolism.