The clinical management of patients with primary or metastatic brain cancer is often challenging. As with all types of cancer, patients with brain cancer are at increased risk of deep vein thrombosis and consequently pulmonary embolism.
It is common for clinicians to be faced with the question of how to safely utilize prophylactic and therapeutic anticoagulation in these patients in the setting of increased risk of intracranial bleeding from the intracranial lesions.
Aside from the inherent risk of clotting secondary to malignancy itself, patients with brain cancer can be at even more risk based on resulting neurological deficits leading to decreased mobility along with any postoperative states they may experience.
The incidence of venous thromboembolism (VTE) varies in studies between approximately 7.5% and approximately 25%.1,2
Risk factors associated with VTE in brain cancer patients include: gliobastomas, chemotherapy, older age, neurosurgery within last 2 months, and 3 or more chronic comorbidities.1 Patients with brain cancer diagnosed with VTE also have a higher 2-year mortality risk.1
When evaluating the need for anticoagulation in patients with brain cancer, numerous factors must be accounted for. Patients with a prior history of intracranial hemorrhage (ICH), platelet count less than 50,000, or increased risk of bleeding (eg, history of disseminated intravascular coagulation) are typically not anticoagulated because the risk outweighs the benefit.1
Both primary brain tumors and metastases (especially from primary melanoma, renal cell carcinoma, or thyroid cancer) can spontaneously bleed without anticoagulation, which may make the risk of ICH too excessive.
In patients who have no known history of brain metastases but have been diagnosed with cancers that frequently metastasize to the brain (eg, melanoma, lung cancer, breast cancer, and thyroid cancer), imaging may be useful prior to initiation of anticoagulation in attempts of detecting metastatic lesions.
However, there are no formal guidelines on obtaining imaging in these scenarios. When imaging is being considered, MRI is typically preferred over CT when evaluating the brain for metastases.