Non-Vitamin K Antagonist Oral Anticoagulants versus Low Molecular Weight Heparin for Cancer-Related Venous Thromboembolic Events: Individual Patient Data Meta-Analysis

Simple Summary Low molecular weight heparin (LMWH) has been the standard of care for venous thromboembolism (VTE) but new guidelines approved using non-vitamin K antagonist oral anticoagulants (NOAC). By conducting an individual patient data meta-analysis of randomised controlled trials (RCTs) comparing the outcomes of NOAC versus LMWH in cancer patients, we aim to determine an ideal strategy for the prophylaxis of VTE and prevention of VTE recurrence. Our study further addresses the conflicting evidence in the literature with an individual patient data meta-analysis. However, other studies are required to balance the risk of recurrent VTE and bleeding among different cancer subgroups. Emerging data highlight the need for individualised antithrombotic strategies to achieve optimal management of cancer patients.Abstract Venous thromboembolism (VTE) is a leading cause of morbidity and mortality in cancer patients. Low molecular weight heparin (LMWH) has been the standard of care but new guidelines have approved the use of non-vitamin K antagonist oral anticoagulants (NOAC). By conducting an individual patient data (IPD) meta-analysis of randomised controlled trials (RCTs) comparing the outcomes of NOAC versus LMWH in cancer patients, we aim to determine an ideal strategy for the prophylaxis of VTE and prevention of VTE recurrence. Three databases were searched from inception until 19 October 2022. IPD was reconstructed from Kaplan-Meier curves. Shared frailty, stratified Cox and Royston-Parmar models were fit to compare the outcomes of venous thromboembolism recurrence and major bleeding. For studies without Kaplan-Meier curves, aggregate data meta-analysis was conducted using random-effects models. Eleven RCTs involving 4844 patients were included. Aggregate data meta-analysis showed that administering NOACs led to a significantly lower risk of recurrent VTE (RR = 0.65; 95%CI: 0.50-0.84) and deep vein thrombosis (DVT) (RR = 0.60; 95%CI: 0.40-0.90). In the IPD meta-analysis, NOAC when compared with LMWH has an HR of 0.65 (95%CI: 0.49-0.86) for VTE recurrence. Stratified Cox and Royston-Parmar models demonstrated similar results. In reducing risks of recurrent VTE and DVT among cancer patients, NOACs are superior to LMWHs without increased major bleeding.