Patients with glioma receiving therapeutic anticoagulation had a greater than threefold risk for intracranial hemorrhage, according to the results of a meta-analysis.
However, patients receiving anticoagulation for brain metastases did not have an increased intracranial hemorrhage risk, results showed.
Venous thromboembolism occurs in 15% to 30% of patients with glioma, which often prompts the initiation of therapeutic anticoagulation. However, the routine use of anticoagulation remains controversial due to the increased risk for intracranial hemorrhage in patients with brain tumors.
Jeffrey I. Zwicker, MD, associate professor of medicine at Harvard Medical School and member of the developmental therapeutics unit at Beth Israel Deaconess Medical Center, and colleagues conducted a meta-analysis of nine retrospective cohort studies to determine whether therapeutic anticoagulation was associated with an increased risk for intracranial hemorrhage in this patient population.
Five studies included patients with gliomas only and three studies included patients with brain metastases only. The remaining study included patients with gliomas and brain metastases.
Zwicker and colleagues calculated a pooled OR for intracranial hemorrhage of 2.13 (95% CI, 1-4.57; I2 = 46%) among patients receiving anticoagulation compared with patients not receiving anticoagulation.
Four studies included patients receiving warfarin or low–molecular-weight heparin; the risk for intracranial hemorrhage was not influenced by treatment with low–molecular-weight heparin vs. warfarin (pooled OR = 0.75; 95% CI, 0.24-2.33; I2 = 0).
The researchers did not observe an increase in intracranial hemorrhages among patients with brain metastases (OR = 1.07; 95% CI, 95% CI, 0.61-1.88). A subset analysis of patients with renal cell carcinoma or melanoma and brain metastases — tumors associated with a high hemorrhage risk — further showed no significant increase (OR = 2.3; 95% CI, 0.8-6.59).
In contrast, patients with glioma had a significantly increased risk for intracranial hemorrhage (pooled OR = 3.75; 95% CI, 1.42-9.95; I2 = 33%).
The researchers acknowledged the lack of prospective studies in their meta-analysis as a potential limitation.
“While anticoagulation may increase the risk for intracranial hemorrhage in patients with glioma, higher quality studies are required in order to better evaluate the absolute increased risk associated with therapeutic anticoagulation,” Zwicker and colleagues wrote. “In the interim, we believe the existing data support the use of therapeutic anticoagulation in the absence of contraindications, in accordance with current recommendations.” – by Cameron Kelsall
Disclosure: The researchers report no relevant financial disclosures.