Low molecular weight heparin is more effective than vitamin K antagonists for venous thromboembolism in cancer patients

Clinical question: 
How effective and safe are low molecular weight heparin (LMWH) and anticoagulants such as vitamin K antagonists (VKA) for the long term treatment of venous thromboembolism (VTE) in patients with cancer?
Bottom line: 
For the long term treatment (up to 6 months) of VTE in patients with cancer, LMWH compared to VKA reduces venous thromboembolic events but not death. Both drugs have equal effects on death and the adverse risk of bleeding and thrombocytopenia.The decision to start long term LMWH versus oral anticoagulation for a patient with cancer and VTE should balance the benefits and downsides and integrate the patient’s values and preferences for the important outcomes and alternative management strategies.
Caveat: 
The authors were unable to include a number of possibly relevant studies because the required data were not available.While LMWH decreases the incidence of VTE, it might be more costly and less acceptable because of the subcutaneous route of administration.
Context: 
The presence of cancer increases the risk of VTE four to six-fold.¹ Patients with cancer might also respond differently to anticoagulants compared with patients without cancer. LMWH is given by injection, whereas VKA is given orally. 1. Heit J A et al. Arch Intern Med 2000;160:809–815.
Review CD#: 
CD006650
PEARLS No: 
97
Date: 
September, 2008
Authored by: 
Brian R McAvoy