Anticoagulation in the management of venous thromboembolism in the cancer patient.

Cancer is associated with a four to sevenfold increased risk of venous thromboembolism (VTE). This risk is influenced by the site and extent of cancer and its treatment. Despite its availability, effective VTE prophylaxis is used in less than 50% of oncology patients. Pharmacologic VTE prophylaxis should be administered to all hospitalized medical and surgical oncology patients for the duration of their hospitalization or up to 10-14 days, whichever is longer. Extended duration (up to 4 weeks post-operation) VTE prophylaxis is recommended for high-risk surgical oncology patients. Routine use of prophylaxis in ambulatory medical oncology patients awaits prospective testing of VTE risk assessment models. Routine prophylactic dose anticoagulation to prevent central venous catheter (CVC) thrombosis is ineffective and not indicated. Low molecular weight heparin is the first line choice for acute and chronic therapy of VTE in cancer patients. Therapy should continue for at least 3 months or the duration of the malignancy, whichever is longer. Anticoagulation is indicated for at least 3 months or the duration of the catheter for CVC thrombosis. Preliminary data indicate that some cancer patients with pulmonary embolism may be managed as outpatients. Prospective validation of these studies and testing of current risk assessment strategies in oncology patients is warranted. Management of recurrent VTE and unsuspected VTE in the cancer patient are also reviewed.