PB0938 - Direct oral anticoagulants versus low molecular weight heparins in patients with brain tumor receiving therapeutic anticoagulation: a systematic review and meta-analysis

Background: Patients with brain tumor have been underrepresented or excluded in recent randomized controlled trials comparing direct oral anticoagulants (DOAC) to low-molecular weight heparins (LMWH) for the treatment of cancer-associated thrombosis (CAT). Nevertheless, results from small retrospective studies suggest that DOAC may be associated with a lower risk of intracranial hemorrhage (ICH) than LMWH in this patient population.

Aims: To perform a meta-analysis of all studies comparing DOAC with LMWH in patients with brain tumor receiving therapeutic anticoagulation for CAT.

Methods: Embase, MEDLINE, and CENTRAL were searched up to January 2023. The primary safety outcome was ICH. The primary efficacy outcome was recurrent CAT. Pooled relative risk (RR) and 95% confidence interval (CI) were calculated using a random effects model.

Results: Six retrospective studies were included. In patients with primary or metastatic brain tumor, the rate of ICH was 6.8% in DOAC-treated patients vs. 23.9%; in LMWH-treated patients (RR, 0.40; 95%CI, 0.24-0.67; I² 0%; 6 studies, 655 patients) while the rates of recurrent CAT were 1.0% and 3.9%, respectively (RR, 0.44; 95%CI, 0.09-2.04; I² 0%; 4 studies, 276 patients). In sensitivity analyses of patients with primary brain tumor only, ICH occurred in 2.7% of DOAC-treated patients vs. 20.6% of LMWH-treated patients (RR, 0.22; 95%CI, 0.08-0.64; I² 0%; 4 studies, 325 patients); rates of recurrent CAT were similar in both groups (1.1% vs. 3.6%; RR, 0.52; 95%CI, 0.11-2.56; I² 0%; 3 studies, 258 patients). In contrast, sensitivity analyses of patients with brain metastases showed similar rates of ICH in DOAC- and LMWH-treated patients (14.3% vs. 35.6%; RR, 0.60; 95%CI, 0.34-1.07; I² 0%; 3 studies, 219 patients).

Conclusion(s): Our results suggest that DOAC might be associated with a low risk of ICH in patients with primary brain tumor. However, they should be interpreted with caution since we included only data from small retrospective studies.