Thromboprophylaxis with low-molecular-weight heparin in medical patients with cancer.

Venous thromboembolism (VTE) is a frequent complication of cancer and cancer treatment and is associated with multiple clinical consequences, including recurrent VTE, bleeding, and an increase in the risk of death. Although the risks associated with VTE have been well recognized in surgical cancer patients, there is also considerable and increasing risk in medical cancer patients. VTE risk factors in medical cancer patients include the type and stage of cancer, major comorbid illnesses, current hospitalization, active chemotherapy, hormone therapy, and antiangiogenic agents. Low-molecular-weight heparins (LMWHs) are recommended commonly for the prevention of VTE in hospitalized cancer patients and in higher risk ambulatory cancer patients because of their favorable risk-to-benefit profile. These agents have demonstrated effectiveness in both the primary and secondary prevention of VTE in medical cancer patients. Extended-duration anticoagulant therapy is often recommended to reduce the risk of VTE recurrence in patients with cancer. LMWHs are often used for long-term prophylaxis because of a reduced need for coagulation monitoring, few major bleeding episodes, and once-daily dosing. Despite clinical and practical benefits, a substantial proportion of medical cancer patients do not receive VTE prophylaxis. To improve the appropriate prevention and treatment of VTE in cancer patients, guidelines have been published recently by the American Society of Clinical Oncology and the National Comprehensive Cancer Network. Widespread dissemination and application of these guidelines are encouraged to improve the appropriate use of these agents and to improve clinical outcomes in medical cancer patients at risk for VTE and its complications.