Anticoagulant Therapy Safe for Patients with Brain Metastases

New research should reassure physicians that anticoagulants can be safely delivered to cancer patients with brain metastases and a history of blood clots, according to the authors.

A team of investigators led by Jeffrey Zwicker, MD, an assistant professor in the department of medicine at Harvard Medical School, evaluated patients with brain metastases in an effort to determine if administering therapeutic enoxaparin is linked to an increased risk for hemorrhage. Among the 293 patients with confirmed brain metastases in the control-matched cohort study, 104 were assigned to enoxaparin therapy, with 189 assigned to the control group. According to Zwicker and his colleagues, the predominant cancer subgroups in the study were non-small cell lung cancer, followed by breast cancer, renal cell carcinoma, and melanoma.
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Aspirin use, they report, was significantly lower in the enoxaparin group than in the control group (4.8% vs 15.3%, which the authors note is ostensibly due to prescriber caution in administering dual antithrombotic therapy (aspirin and anticoagulant). The enoxaparin regimen varied, with 76 patients (73.1%) receiving enoxaparin 1 mg/kg twice daily, 17 (16.3%) receiving 1.5 mg/kg once daily, and 11 (10.6%) with thrombocytopenia or renal failure receiving a reduced-dose modified regimen.

In 88 patients, or 84.6%, enoxaparin treatment was initiated after the diagnosis of brain metastases.

The rate of significant intracranial hemorrhage did not differ between the two groups.

At 1 year, the cumulative incidence of measurable intracranial hemorrhage was 19% in the enoxaparin group and 21% in the control group, while the majority of hemorrhages were symptomatic in both groups. In addition, the cumulative incidence of total intracranial hemorrhage was 44% in the enoxaparin group and 37% in the control group.

Among those experiencing significant hemorrhage, neurosurgical intervention was required more often in the enoxaparin group than in the control group. In addition, the risk for intracranial hemorrhage was four-fold higher in the 60 patients with melanoma or renal cell carcinoma than in the 153 with lung cancer.

Given such findings, “therapeutic anticoagulation should be considered for the treatment of patient diagnosed with venous thromboembolism,” says Zwicker, “even in the setting of known brain metastases.  

—Mark McGraw

Reference

Donato J, Campigotto F, et al. Intracranial hemorrhage in patients with brain metastases treated with therapeutic enoxaparin: a matched cohort study. Blood. 2015.