A retrospective single-center evaluation of the safety and efficacy of direct oral anticoagulants versus low molecular weight heparin in patients with cancer-associated thrombosis.

Abstract

e24102 Background: Over the past decade, there has been an increase in the use of direct oral anticoagulants (DOACs) in the cancer population despite limited data comparing its use against low molecular weight heparin (LMWH), the standard of care in cancer patients. Increasing data supporting DOACs in cancer-associated thrombosis has emerged over the past few years. Nonetheless, this study will evaluate the relative safety and efficacy of DOACs versus LMWH in cancer-associated thrombosis within an urban setting associated with low socioeconomic status. Methods: This is a retrospective chart review of medical records from patients treated at an urban academic medical center from October 2010 through October 2018. Patients met study inclusion if they had a diagnosis of venous thromboembolism occurring after the date of diagnosis of active cancer and were prescribed a direct oral anticoagulant (rivaroxaban, apixaban, dabigatran, edoxaban) or a low molecular weight heparin (dalteparin, enoxaparin, or fondaparinux) as monotherapy for the treatment of venous thromboembolic disease. Patients were excluded if they had less than 6 months of follow up data for reasons other than death. The primary outcomes were recurrent venous thromboembolism, major bleeding and death. Results: Of the 914 patients who met inclusion criteria, 286 were excluded due to lack of follow up data. The remaining patients included 472 in the LMWH arm and 156 in the DOAC arm. At 6 months, recurrent thromboembolism occurred in 5 of the 472 patients (1.1%) in the LMWH group as compared with 4 of the 156 patients (2.6%) in the DOAC group (p = 0.170). Major bleeding occurred in 36 patients (7.6%) in the LMWH group and 11 patients (7.0%) in the DOAC group (p = 0.813). Death within 6 months of starting anticoagulation occurred in 76 patients (16.1%) in the LMWH group and 16 patients (9.6%) in the DOAC group (p = 0.046). Discontinuation before 6 months of treatment occurred in 241 patients (51.2%) in the LMWH group and 46 patients (29.5%) in the DOAC group. Conclusions: The LMWH and DOAC groups had similar rates of recurrent thromboembolism and major bleeding. The mortality rate within 6 months of starting anticoagulation was significantly higher in the LMWH group and this difference requires further evaluation. These results help support the continued use of DOACs for the treatment of cancer-associated thrombosis and demonstrate that DOACs are as safe and effective as LMWH in this patient population.