Venous thromboembolism and cancer.

The association of thrombosis with malignant disease has been recognized for well over 100 years. Evidence from experimental and clinical studies indicates that the haemostatic system is involved in the growth, invasion and metastasis of tumours. Laboratory parameters of haemostasis are frequently deranged in patients with cancer and overt thrombosis is common spontaneously where it may be the first sign of malignancy or secondary to therapy. The mechanisms by which coagulation activation facilitates the malignant process remain to be completely elucidated, but it is clear that cells and proteins of the coagulation and fibrinolytic systems are involved at many steps in the processes of tumour growth and dissemination. The low-molecular-weight heparins with their well-proven safety and efficacy profiles offer unique modalities for the prevention and treatment of cancer-associated thrombosis. They may also play a role in overall mortality reduction in patients with malignant disease.