Treatment of established thrombotic events in patients with cancer.

Acutely ill medical patients with cancer and cancer patients requiring Anticoagulants remain the cornerstone of therapy for venous thromboembolism. In patients with cancer, monotherapy with low molecular weight heparin (LMWH) is preferred over initial therapy with heparin followed by long-term treatment with vitamin K antagonists (VKA) because it is more efficacious and does not interfere with chemotherapy. The shorter duration of action of LMWHs compared with VKAs also offers greater flexibility to accommodate invasive procedures and thrombocytopenia. Newer oral antithrombotic agents may further simplify treatment of cancer-associated thrombosis because they are given at fixed doses and do not require laboratory monitoring of their anticoagulant effect. However, there are very limited data and experience with these agents in patients with cancer and some of these drugs do interact with a number of chemotherapeutic agents. Other unanswered clinical questions include the optimal duration of anticoagulant therapy, which anticoagulant to use after 6 months of treatment, how to treat patients with recurrent thrombosis or patients with a high risk for bleeding. Formal studies are needed to address these unmet clinical needs.