Trends in Anticoagulant Utilization and Clinical Outcomes for Cancer-Associated Thrombosis: A Multicenter Cohort Study in Thailand's Upper-Middle-Income Country Setting

Abstract

PURPOSE: To evaluate anticoagulant trends and clinical outcomes in the management of cancer-associated thrombosis (CAT) within Thailand, an upper-middle-income country (UMIC). METHODS: This multicenter retrospective cohort study included adult patients with cancer diagnosed with venous thromboembolism (VTE) hospitalized in Thailand from 2017 to 2021. Anticoagulants were classified as low-molecular-weight heparin (LMWH), direct oral anticoagulants (DOACs), and warfarin. Prescription trends were assessed, and patients were followed for 1 year, or until 2022 to evaluate outcomes. The primary effectiveness outcome was recurrent VTE, whereas the primary safety outcome was major bleeding. Secondary outcomes included net clinical benefit and all-cause mortality. Treatment effects were examined using inverse probability of treatment weighting (IPTW) Cox proportional hazards models. RESULTS: Among 1,611 patients (61.3% female; mean age, 58.8 years; standard deviation, 13.1 years), 86% received LMWH, 10% warfarin, and 4% DOACs. In the study cohort, LMWH prescriptions remained consistent, warfarin use declined, and DOAC prescriptions notably increased. In IPTW analysis, DOACs showed comparable rates of VTE recurrence (weighted hazard ratio [HR], 0.77 [95% CI, 0.22 to 2.70]; P = .679) and major bleeding (weighted HR, 0.62 [95% CI, 0.15 to 2.55]; P = .506) with LMWH. Warfarin had a higher risk of major bleeding (weighted HR, 2.74 [95% CI, 1.12 to 6.72]; P = .028) but a similar rate of VTE recurrence (weighted HR, 1.46 [95% CI, 0.75 to 2.84]; P = .271) compared with LMWH. Secondary outcomes were consistent across groups. CONCLUSION: LMWH remains the primary treatment for CAT, in line with current guidelines. The study highlights the challenges faced in these settings with the continuous use of warfarin. The comparable efficacy and safety of DOACs with LMWH suggest a potential shift in CAT management within UMICs.