Practical problems and resource implications with the use of warfarin for venous thromboembolism in patients with cancer

The potential benefits of low-molecular-weight heparins in cancer patients

Cancer patients are at increased risk of venous thromboembolism due to a range of factors directly related to their disease and its treatment. Given the high incidence of post-surgical venous thromboembolism in cancer patients and the poor outcomes associated with its development, thromboprophylaxis is warranted. A number of evidence-based guidelines delineate anticoagulation regimens for venous thromboembolism treatment, primary and secondary prophylaxis, and long-term anticoagulation in cancer patients. However, many give equal weight to several different drugs and do not make specific recommendations regarding duration of therapy. In terms of their efficacy and safety profiles, practicality of use, and cost-effectiveness the low-molecular-weight heparins are at least comparable to, and offer several advantages over, other available antithrombotics in cancer patients. In addition, data are emerging that the antithrombotics, and particularly low-molecular-weight heparins, may exert an antitumor effect which could contribute to improved survival in cancer patients when given for long-term prophylaxis. Such findings reinforce the importance of thromboprophylaxis with low-molecular-weight heparin in cancer patients.

Use of Low-Molecular-Weight Heparin for the Treatment of Venous Thromboembolism in Patients with Cancer: A Review of the Literature

Objective:

To evaluate the literature on use of low-molecular-weight heparin (LMWH) for the treatment of venous thromboembolism (VTE) in patients with cancer for the first 3–6 months of anticoagulant therapy.

Data Sources:

A preliminary literature search of PubMed (1966–May 2009) was performed, using the MeSH database when possible, with the terms venous thromboembolism, venous thrombosis, pulmonary embolism, neoplasm, vitamin K antagonist, and low-molecular-weight heparin. Bibliographies of all articles retrieved were also reviewed.

Study Selection and Data Extraction:

All studies published in English with data describing the safety and/or efficacy of LMWH in subjects with cancer for the first 3–6 months of anticoagulant therapy for VTE were included.

Data Synthesis:

Five studies that met the above criteria were identified. When compared with vitamin K antagonists, LMWH therapy decreased recurrent VTE in subjects with cancer. Many of these studies had important limitations, including open-label design, relatively short duration, ineffective LMWH dosing, and small sample size.

Conclusions:

The studies analyzed support the American College of Chest Physicians Evidence-Based Clinical Practice Guidelines' recommendation for the use of LMWH for the first 3–6 months of anticoagulant therapy for VTE in patients with cancer. Specifically, in clinical trials, tinzaparin and dalteparin have demonstrated increased efficacy compared with vitamin K antagonists.

ACPE Universal Program Number:

407-000-09-055-H01-P (Pharmacists)