Venous thromboembolism in lymphoma: how effectively are we treating patients?

INTRODUCTION: Patients with solid tumors and venous thromboembolic episodes (VTE) have a high risk of recurrence and bleeding during oral anticoagulant treatment. However, we are unaware of studies expressly evaluating such risks in patients with lymphoma. Therefore, we conducted a retrospective study to determine the frequency of such complications during treatment of lymphoma patients who develop VTE. METHODS: Charts of patients with histologically proven non-Hodgkin lymphoma and Hodgkin lymphoma were retrospectively reviewed and patients with their first acute symptomatic VTE episode were identified (49 non-Hodgkin lymphoma, 8 Hodgkin lymphoma). Recurrence of VTE episodes and major and minor bleeding during treatment with warfarin or low molecular weight heparin (LMWH) were recorded. RESULTS: All 57 patients were initially treated with high-dose-adjusted intravenous heparin or body-weight-adjusted LMWH. Forty-six patients were started on oral warfarin and 11 patients continued LMWH. Recurrent VTE episodes occurred in 14 of 46 patients on warfarin therapy, whereas major bleeding was documented in 6 of 46 patients, and minor bleeding in 9 of 46 patients. Recurrent VTE episodes occurred in 1 of 11 patients treated with LMWH, whereas major bleeding occurred in 0 of 11 and minor bleeding in 3 of 11 patients. CONCLUSIONS: Lymphoma patients treated with warfarin experienced a 30.4% rate of recurrent thrombosis and 13% major bleeding. During this treatment most (65%), but not all, bleeding and thrombotic complications occurred with an international normalized ratio within the therapeutic range. The percentage of serious complications (recurrent VTE and major bleeding) during warfarin use was 44.5%, and the death rate was 6.5%, compared with 9% and 0%, respectively, during use of LMWH.