Abstract
BACKGROUND: Direct oral anticoagulants (DOACs) have demonstrated non-inferiority to low-molecular-weight heparin (LMWH) for preventing recurrent venous thromboembolism (VTE) in cancer-associated thrombosis. However, patients with gastrointestinal (GI) cancer receiving DOACs have reported increased major bleeding events. Hereby, we aim to compare the risks of recurrent thromboembolism and bleeding between those treated with DOACs and LMWH. METHODS: Using Taiwan's National Health Insurance Research Database, we retrospectively identified GI cancer patients with newly diagnosed VTE from 2011 to 2020. Outcomes were recurrent VTE and major bleeding. Covariate balancing was performed using inverse probability weighting, and Cox proportional hazards models compared risks, with a competing risk model for death. Follow-up was 12 months. RESULTS: Among 1895 patients (1038 on DOACs, 857 on enoxaparin), recurrent VTE occurred in 20.71% of DOAC and 19.25% of enoxaparin patients. Competing risk analysis showed relatively higher recurrent VTE risk with DOACs (subdistribution HR, 1.27; 95% CI, 1.09-1.48; p < 0.01). Regarding composite bleeding risk, DOACs were similar compared with LMWH (subdistribution HR, 0.99; 95% CI, 0.68-1.45; p = 0.97). However, DOACs presented with an increased GI bleeding risk (subdistribution HR, 2.59; 95% CI, 1.48-4.54; p < 0.01) but a reduced intracranial hemorrhage risk (subdistribution HR, 0.35; 95% CI, 0.16-0.78; p = 0.01). CONCLUSIONS: Compared with DOACs, LMWH expressed a lower risk of recurrent VTE in GI cancer patients. However, DOAC presented with a lower intracranial hemorrhage risk but a higher GI bleeding risk. Further research is needed to confirm these findings.