Comparison of rivaroxaban and dalteparin for the long-term treatment of venous thromboembolism in patients with gynecologic cancers

OBJECTIVES: Two randomized, controlled studies comparing outcomes in patients treated with direct oral anticoagulants or low-molecular weight heparin for cancer-associated venous thromboembolism (VTE) have previously been performed. However, gynecologic cancers accounted for approximately 10% of the study populations. We compared the outcomes of patients with primary gynecological cancers who were treated for cancer-associated VTE with either rivaroxaban or dalteparin. METHODS: The 162 eligible patients with gynecologic cancers who were treated with either dalteparin (n=60) or rivaroxaban (n=102) were reviewed. The primary outcome was a composite event, which included recurrence or clinically relevant bleeding events during the therapeutic period. Secondary outcomes were recurrence, clinically relevant bleeding events, and mortality. RESULTS: During the therapeutic period, there were no significant differences between the groups in the proportion of composite events, recurrence, or clinically relevant bleeding. Multivariate analysis using the Cox proportional hazards model also showed no significant difference in the number of composite events and clinically relevant bleeding between the groups. In the rivaroxaban group, 44.0% of patients experienced gastrointestinal bleeding and 24.0% experienced urinary tract bleeding. In the dalteparin group, bleeding was most common in the urinary tract (44.4%) and at the injection site (22.2%). CONCLUSION: In this study, although there were no significant differences in effectiveness or safety between the rivaroxaban and dalteparin groups, rivaroxaban use was associated with a higher rate of clinically relevant bleeding than dalteparin. Therefore, caution should be taken when prescribing rivaroxaban for gynecologic cancer-associated VTE and bleeding events should be carefully monitored.