Prevention of venous thromboembolism in cancer patients.

Thrombosis is a common complication in patients with malignancy and its occurrence is heightened by therapeutic interventions such as operations or the use of chemotherapy. The magnitude of the risk for venous thromboembolism (VTE) is well established for cancer surgery where rates twice that for abdominal surgery in noncancer subjects are described. The case for routine thromboprophylaxis in patients receiving chemotherapy is less clear, and prospective studies investigating rates of thrombosis by tumor type, stage of disease, and chemotherapeutic regimens are required. For thromboprophylaxis in the surgical patient either low-dose heparin or low-molecular-weight (LMW) heparin are effective and safe. For patients receiving chemotherapy in advanced breast cancer, low-dose warfarin is effective. Interestingly, heparin therapy may prolong survival in patients with malignant disease; the mechanism is unclear, and observations from retrospective analysis need to be confirmed in prospective studies.