Venous thromboembolism is a product in proliferation of cancer cells.

The pathogenesis of venous thromboembolism (VTE) in patients with cancer is related to the destruction of small veins and the intravenous formation of filamentous mesh-like structure by fibrinogen. The filamentous mesh-like filter can block hematogenous metastasis of cancer cells and also can stagnate blood cells, leading to venous thrombosis. Cancer cells have characteristics of malignancy and fast proliferation, and ischemic necrosis frequently occurs, and small veins were invaded and damaged. The formation of filamentous mesh-like structure has defense function and also may cause the occurrence of VTE. VTE is a product of the proliferation process of malignant cells.