Cancer, thrombosis and heparin-induced thrombocytopenia.

Venous thromboembolism (VTE) is a common occurrence in patients with cancer, and can sometimes precede the development of the clinical manifestations of cancer. The pathogenetic mechanisms of thrombosis involve a complex interaction between tumour cells and the host haemostatic system, in addition to cancer-related clinical risk factors. The risk of VTE increases in presence of distant metastases. The development of VTE in patients with cancer is a strong predictor of decreased survival. The most common medical situations that make cancer patients at a higher risk of VTE include immobilization and chemotherapy with or without adjuvant hormone therapy. Recent findings suggest that heparin-induced thrombocytopenia (HIT) and HIT-related thrombotic complications may occur in cancer patients with a higher frequency than in patients free from malignancy. Thromboembolism is a well-recognised complication of malignant disease. Clinical manifestations vary from venous thromboembolism (VTE) to disseminated intravascular coagulation, more commonly observed in patients with haematological malignancies and those with widespread metastatic cancer, to arterial embolism, more commonly observed in patients undergoing chemotherapy and in those with non-bacterial thrombotic endocarditis.