The risk of thrombosis among patients with cancer is much higher than in the general population. Against the background of oncological diseases, relapses of thromboembolic complications and major bleeding during anticoagulant therapy are more common1. Several clinical studies have evaluated the efficacy and safety of long-term administration of low molecular weight heparin (LMWH) to cancer patients in comparison with vitamin K antagonist (VKA). This paper aims to discuss and provide evidence for prescribing LMWH over VKA in patients with venous thromboembolism and cancer.
The American College of Chest Physicians (ACCP) and the National Comprehensive Cancer Network (NCCN) have provided basic guidelines for the management of these patients. The studies compared warfarin and LMWH enoxaparin that was used for 3 months in patients with deep vein thrombosis (DVT) and pulmonary embolism as secondary prevention2. According to the authors, enoxaparin may be as effective as warfarin with long-term use. At the same time, warfarin therapy was associated with a high risk of bleeding.
The larger CLOT study, in which 672 patients with malignant neoplasms were randomized, compared two treatment regimens: VKA for 6 months after 5-7 days of dalteparin, and LMWH alone for 6 months3. In the dalteparin group, the cumulative risk of thromboembolic complications recurrence was reduced to 9% compared to 17% in the VKA group3. Besides, there was no increase in the risk of major bleeding.
When treating thromboembolism in oncological patients, preference is given to low molecular weight heparin which is used during the first 6 months. After this period, LMWH should be continued indefinitely, or until the cancer is considered cured. According to experts in the field of thromboembolism prevention and therapy, data obtained from numerous studies of antithrombotic drugs in cancer patients must be used in everyday clinical practice.
Reference List
Dranitsaris G, Shane LG, Crowther M, et al. Dalteparin versus vitamin K antagonists for the prevention of recurrent venous thromboembolism in patients with cancer and renal impairment: A Canadian pharmacoeconomic analysis. Clinicoecon Outcomes Res. 2017;9:65-73.
Kearon C, Akl EA, Ornelas J, et al. Antithrombotic therapy for VTE Disease: CHEST guideline and expert panel report. Chest. 2016;149(2):315-352.
Woodruff S, Lee AY, Carrier M, et al. Low-molecular-weight-heparin versus a coumarin for the prevention of recurrent venous thromboembolism in high-and low-risk patients with active cancer: A post hoc analysis of the CLOT study. J Thromb Thrombolysis. 2019;47(4):495-504.