Recurrence of Venous Thromboembolism in Patients With Cancer Treated With Warfarin

Venous thromboembolism (VTE) is a common complication in patients with cancer. Previous randomized studies have demonstrated that the rates of recurrent VTE are lower in patients treated with low-molecular-weight heparin compared to warfarin. We performed a retrospective analysis of 236 patients with cancer managed by a dedicated oncology anticoagulation management service to compare "real-world" rates of recurrent VTE and bleeding in patients treated with warfarin versus parenteral anticoagulants. Initial anticoagulant regimen included a parenteral agent with transition to warfarin in 132 (55.9%) patients, enoxaparin in 53 (22.5%), dalteparin in 37 (15.7%), and fondaparinux in 14 (5.9%). Taking into account the competing risk of death, cumulative incidence of VTE recurrence at 6 months was 4.0% with warfarin, 10.3% with enoxaparin, 3.0% with dalteparin, and 7.7% with fondaparinux (P = .004). Bleeding complications occurred in 10.6% of patients on warfarin, 17.0% on enoxaparin, 27.0% on dalteparin, and 14.3% on fondaparinux (P = .089). In a dedicated anticoagulation clinic, specific for patients with cancer, warfarin may be an acceptable treatment for first thrombotic events in patients with cancer.