Table 1.

Summary of pro-thrombotic elements observed in cancer.

Mediator	Origin	Mechanism
Tissue factor (TF)	○Platelets ○Malignant cell expressed ○Malignant cell secreted microparticles	○Activates platelets ○Activates extrinsic clotting cascade ○Binds with Factor Vll/Vlla and this complex activates Factor IX to IXa and Factor X to Xa ○Ultimately increases activation of prothrombin to thrombin
Matrix metaloprotease	○Native cell secreted ○Malignant cell secreted	○Activates platelets independent of TF ○Increases platelet binding to fibrinogen increases platelet aggregation
Vascular endothelial growth factor (VEGF)	○Native cell secreted ○Malignant cell secreted	○Increases VonWillebrand Factor expression on endothelial cells, promoting platelet aggregation ○Increases endothelial permeability, exposing cells and clotting factors to extravascular TF ○Draws pro-inflammatory leukocytes, which complex with platelets and form microthrombi
Cancer Procoagulant	○Malignant cells only	○Activates FX to FXa independent of TF
Heparanase	○Platelets ○Neutrophils ○Monocytes ○Malignant cell cytoplasm malignant cell secreted	○Enhances TF activity ○Activates VEGF, increases neoangiogenesis