Abstract
Venous thromboembolism (VTE) is common in patients with brain tumors, occurring in
up to 30% of patients with high-grade glioma and up to 20% of those with brain metastasis
and primary central nervous system (CNS) lymphoma. The risk is correlated with higher
grade malignancies and is directly associated with the production of the potent procoagulant,
tissue factor (TF). Upregulation of TF influences both the coagulation pathway and
oncogenic signaling mechanisms important for cancer progression. The risk of intracranial
hemorrhage with the use of anticoagulants complicates the management of VTE in patients
with brain tumor. We discuss the recommended anticoagulants used for initial and long-term
treatment of established VTE, including unfractionated heparin, low-molecular-weight
heparin (LMWH), and warfarin. Therapeutic anticoagulation, particularly LMWH followed
by secondary prophylaxis, is generally safe and effective in the treatment of VTE,
including patients on antiangiogenic agents. Anticoagulation also reduces the risk
of VTE during the perioperative period. However, despite the high risk of VTE throughout
the course of disease, present data do not support routine thromboprophylaxis in brain
tumor patients. Further investigation regarding the mechanisms underlying the hypercoagulable
state of patients with brain tumors and the potential role of the factors and products
of thrombogenesis as biomarkers for risk stratification will be useful in identification
and management of patients at risk of developing VTE. Novel oral anticoagulants that
directly inhibit thrombin such as dabigatran or factor Xa, including rivaroxaban and
apixaban have several potential advantages; however, due to limited data in the cancer
population, the use of these newer oral anticoagulants is not currently recommended
for patients with malignancy and VTE. Recent studies have explored the role of anticoagulants
as anticancer agents, which may contribute to cancer treatment in the future.
Keywords
thromboembolism - brain tumors - glioma - tissue factor - bevacizumab
