Anti-thrombotic therapy in cancer patients

Abstract

A complex relationship exists between the coagulation system and tumour cells, with common mechanisms linking haemostasis and malignancy. Venous thromboembolism (VTE) is the second most common cause of death in cancer patients and it is estimated that about 1 in 7 patients die of avoidable pulmonary embolism (PE), rather than the cancer itself. Treating a patient with cancer requires a multidisciplinary approach, whether the intention is to cure or to palliate; life expectancy may be improved in certain patients by aggressive intervention, but if a limited life span is expected, preserving quality of life becomes paramount. Cancer is an independent risk factor for VTE, but cancer patients are also at higher risk of bleeding complications and recurrence. Exciting data from prospective randomised clinical trials in cancer patients have now established that low molecular weight heparins (LMWHs) are the agents of choice both in the primary prevention of venous thromboembolic disease in cancer patients undergoing surgical intervention and in the treatment and long-term secondary prevention of recurrent VTE in cancer patients who develop a thrombosis. These agents can be given safely without need, in general, for routine laboratory monitoring in cancer patients. Anti-thrombotic drugs, and in particular LMWHs, have recently been demonstrated to have potential anti-tumour effects. The survival advantage associated with LMWH usage may be due to a combination of (1) prevention of fatal thromboembolic disease; (2) interference with the coagulation proteases that influence tumour phenotype and (3) a potential direct anti-tumour cell effect of heparin itself.