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KEY CONCEPTS
Venous thromboembolism (VTE) is common in patients with cancer and contributes to their morbidity and mortality.
All hospitalized patients with cancer should be given pharmacologic thromboprophylaxis unless there is a contraindication.
High-risk ambulatory patients with cancer receiving outpatient chemotherapy can be considered candidates for receiving prophylactic-dose apixaban or rivaroxaban.
Cancer-associated VTE treatment with anticoagulation is associated with a higher rate of recurrence and bleeding compared with non–cancer-related VTE, so one must fastidiously review the risk–benefit ratio for each patient before beginning anticoagulation.
Cancer-associated thrombotic microangiopathy is not caused by ADAMTS-13 autoantibodies and does not improve with plasma exchange.
Routine anticoagulation or antiplatelet therapy for cancer patients with atrial fibrillation or coronary artery disease appears to be safe.
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VENOUS THROMBOEMBOLISM
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Pulmonary embolism (PE) and deep vein thrombosis (DVT) are manifestations of venous thromboembolism (VTE). Approximately 20% of all VTEs are associated with cancer, and cancer increases the risk for VTE four- to sixfold. Surgery, chemotherapy, hormonal therapy, growth factors, angiogenesis inhibitors, immunomodulators, erythropoietic agents, and central venous catheters (CVCs) contribute to cancer-associated VTE.1 The risk of VTE is associated with the type of cancer and its clinical stage, with glioblastoma, stomach cancer, pancreatic cancer, lung cancer, gynecologic cancer, and acute leukemia frequently associated with VTE and early-stage breast cancer, prostate cancer, and melanoma least commonly associated with VTE.1 Cancer-associated VTE is rarely lethal within 6 months of diagnosis and treatment,2 but it is often undiagnosed, and its onset can be associated with considerable mortality. VTE was the death certificate–attributed cause of death for 0.21% of patients with cancer in a large population-based death certificate review,3 the objectively documented cause of death among 0.4% of all patients with cancer registered by our institution between 2000 and 2010 (unpublished data), and the cause of death for 5/141 (3.5%) deaths recorded among 4466 community hospital–treated ambulatory patients with cancer.4
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Clinical presentations of VTE are not specific. Most patients with DVT have unilateral leg swelling and tenderness, and most patients with PE have abrupt-onset dyspnea and pleuritic chest pain. VTE can be ruled out in about 97% of cases when there is a low Well's score in conjunction with normal D-dimer levels. A higher Well's score along with elevated D-dimers cannot, however, be used to diagnose VTE in patients with cancer, and radiographic studies are required for all patients in whom VTE cannot be ruled out using Well's criteria and D-dimer levels.5 Doppler with compression ultrasound is the preferred method to diagnose DVT, although magnetic resonance imaging and computed tomography (CT) may be required in special circumstances, such as internal iliac vein or vena cava thrombosis. CT angiography is the best method for diagnosing PE,6 and it offers the advantage of providing additional information regarding synchronous thoracic pathology that may confound the diagnosis. Up to 5% of ...