Breast Cancer-Associated Venous Thromboembolism: Risk Factors, Mechanisms, and Clinical Management

Venous thromboembolism (VTE) is a clinically significant complication in patients with breast cancer (BC) and may disrupt treatment continuity while contributing to adverse outcomes. Although BC is generally regarded as a relatively low-risk malignancy for VTE compared with several other cancer types, its high incidence and the increasing use of multimodal therapies have resulted in a growing clinical burden of breast cancer-associated VTE. This review summarizes the epidemiological features, risk factors, biological mechanisms, and advances in the prevention and management of breast cancer-associated VTE. Current evidence indicates that patients with cancer have an approximately 4- to 7-fold higher risk of VTE than the general population, with the risk in BC being particularly pronounced during the first 3–6 months after diagnosis. Older age, metabolic comorbidities, advanced disease, and exposure to multiple anticancer therapies have all been associated with an increased risk of VTE. Mechanistically, tissue factor, procoagulant extracellular vesicles, neutrophil extracellular traps, and inflammatory signaling pathways may contribute to breast cancer-associated VTE by promoting coagulation activation and endothelial dysfunction, while also linking thrombosis to immune evasion and Smetastatic progression. Improved identification of high-risk patients, optimization of dynamic risk assessment, and the implementation of individualized prophylactic and anticoagulant strategies may help improve outcomes in patients with BC.