Direct oral anticoagulants and low-molecular weight heparin for primary prevention of venous thromboembolism in cancer patients: a meta-analysis

Background: Venous thromboembolism (VTE) is a serious complication among cancer patients necessitating hospitalization. Current guidelines recommend anticoagulation using low molecular weight heparins (LMWH) for prevention of VTE. Recent studies have also demonstrated the efficacy of direct oral anticoagulants (DOACs) in the prevention of VTE among cancer patients. We aimed to assess the efficacy of DOACs and LMWH in primary prevention of VTE among cancer patients, and evaluate the risks of bleeding. Methods: Electronic databases were searched for randomized trials evaluating LMWH and DOACs versus placebo as primary prevention for VTE among cancer patients. The primary outcomes were VTE events and incidence of major and minor bleeding. Studies were assessed using the Cochrane Handbook for Systematic Reviews of Interventions. Results were calculated via RevMan Version 5.3 using fixed-effect modelling. Results: Seven randomized trials (two on DOACs; five on LMWHs) with 7073 patients were included. Both DOACs [RR 0.57; 95% CI 0.38, 0.84, p = 0.004] and LMWH [RR 0.49; CI 95% 0.36, 0.65, p Conclusion: Both DOACs and LMWH are effective in the prevention of VTE among cancer patients without an increase in risk for major bleeding. Compared to LMWH, DOAC may be associated with decreased risk of major bleeding.