Cancer-associated venous thromboembolism
Deep vein thrombosis or pulmonary embolism occurring in a patient with active malignancy, driven by tumor-derived procoagulant activity plus stasis and vascular injury. Diagnosis is confirmed by compression ultrasonography or CT pulmonary angiography, and first-line treatment is apixaban, rivaroxaban, or low molecular weight heparin continued while cancer is active.
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What this article covers
- Overview
Cancer-associated venous thromboembolism (VTE) is deep vein thrombosis (DVT) or pulmonary embolism (PE) arising in a patient with active malignancy, either as the event that leads to a cancer…
- Epidemiology
Cancer-associated VTE clusters around the time of diagnosis and the first months of systemic therapy, and risk climbs further with metastatic spread.
- Risk factors
Tumor site: Gastric and pancreatic cancer carry the highest risk (2 points on the Khorana score); lung, lymphoma, gynecologic, bladder, and testicular cancers are next (1 point each).
- Pathophysiology
Malignant cells constitutively express tissue factor and shed tissue-factor-bearing microparticles into the circulation, directly triggering the extrinsic coagulation cascade.
- Clinical features
Lower-extremity DVT: Unilateral swelling, pain, warmth, and erythema, with a palpable cord and calf tenderness along the deep venous system.
- Differential diagnosis
Tumor-related lymphedema: Chronic, often bilateral limb swelling from nodal obstruction, but ultrasonography shows a fully compressible deep venous system.
- Diagnosis
The gold standard is confirmatory imaging: a noncompressible deep vein on ultrasonography confirms DVT; an intraluminal filling defect on CT pulmonary angiography confirms PE.
- Management
First, for hemodynamically unstable PE, stabilize with unfractionated heparin 80 units/kg IV bolus then 18 units/kg/hr infusion (short half-life, reversible) and evaluate for thrombolysis before transitioning to a maintenance agent.
- Complications
Recurrent VTE: Higher recurrence than in patients without cancer; LMWH reduces recurrence compared with warfarin (9% vs 17% at 6 months) without increasing major bleeding.
- Prognosis
Cancer-associated VTE is associated with worse overall survival than cancer without VTE, and mortality risk is highest in the weeks immediately following the thrombotic event.
- Prevention
First, calculate the Khorana score before starting a new systemic chemotherapy regimen in every ambulatory patient with cancer; routine pharmacologic prophylaxis is not recommended for all outpatients with cancer.
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