Factor Xa inhibitors versus low molecular weight heparin for the treatment of cancer associated venous thromboembolism; A meta-analysis of randomized controlled trials and non-randomized studies

Introduction: We compared the safety and efficacy of Xa-inhibitors to LMWH for treatment of venous thromboembolism in mixed and gastrointestinal cancer cohorts (CA-VTE). Methods: A systematic search identified RCTs and non-randomized studies (NRS) comparing Xa-inhibitors to LMWH for treating CA-VTE. Relative risks were computed. Certainty was assessed using the GRADE approach. Results: Xa-inhibitors reduced the risk of recurrent VTE (RR0.64;0.49-0.84) and NRS (RR0.74;0.60-0.92;Moderate-Low Certainty). There was no significant difference in recurrent PE in RCTs (RR0.72;0.50-1.02) and NRS (1.43;0.65-3.12;Low-Very Low Certainty). Xa-inhibitors increased the risk of overall bleeding events in RCTs (RR1.45;1.05-2.01) and NRS (RR1.72;1.42-2.08;Moderate-Low Certainty), and the risk of major bleeding events in NRS (RR1.56;1.17-2.07), but not in RCTs (RR1.33;0.94-1.89; Low-Very Low Certainty). Similar results were detected in gastrointestinal cancer patients. Conclusion: Xa-inhibitors may reduce the risk of recurrent VTE, but not recurrent PE compared to LMWH. A higher overall bleeding risk, and a questionably higher major bleeding risk was found with Xa-inhibitor use.