Anticoagulant therapy significantly increases the risk of ICH in patients with primary brain cancer but not in those with brain metastases.
The risk of ICH is significantly lower with direct oral anticoagulants compared to low-molecular weight heparins.
Anticoagulant treatment in patients with primary and metastatic brain cancer is a concern due to risk of intracranial hemorrhage (ICH). We performed a systematic review and meta-analysis to evaluate the risk of ICH in patients with primary or metastatic brain cancer treated or not with anticoagulants. Articles on ICH in patients with primary or metastatic brain cancer treated or not with anticoagulants published up to September 2021 were identified by searching PUBMED, EMBASE and CENTRAL.The primary outcome of this analysis was ICH. Thirty studies were included. Rate of ICH was 13.0% in 1,009 patients with metastatic and 6.4% in 2,353 patients with primary brain cancer [Relative risk (RR) 3.26, 95% CI 2.69-3.94; I2 92.8%). In patients with primary brain cancer, ICH occurred in 12.5% and 4.4% of patients treated or not treated with anticoagulants, respectively [11 studies, 659 treated and 1,346 not treated patients, RR 2.63, 95% CI 1.48-4.67, I2 49.6%]. In patients with metastatic brain cancer, ICH occurred in 14.7% and 15.4%, respectively (5 studies, 265 treated and 301 not treated patients, RR 0.92, 95% CI 0.43-1.93, I2 0%). ICH occurred in 8.3% of 172 treated with direct oral anticoagulant (DOAC) and in 11.7% of 278 treated with low-molecular weight heparin (LMWH) (5 studies, RR 0.44, 95% CI 0.25-0.79, I2 0%). Patients with metastatic brain cancer have a particularly high risk of ICH. Patients with primary brain cancer have an increased risk of ICH during anticoagulation. DOACs are associated with a lower risk of ICH than LMWH.