Low-molecular-weight heparins and cancer: focus on antitumoral effect

A close relationship between cancer and thrombosis does exist, documented by the fact that an overall 7-fold increased risk of venous thromboembolism (VTE) has been reported in patients with malignancy compared to non-malignancy. The potential impact of antithrombotic agents in cancer-associated VTE has long been recognized, and, in particular, several clinical trials in the last 20 years have reported the safety and efficacy of low-molecular-weight heparins (LMWHs) for treatment and prophylaxis of VTE in patients with various types of cancer. More recently, a number of preclinical and clinical studies have suggested that LMWHs may improve survival in cancer patients with mechanisms that are different from its antithrombotic effect but are linked to the ability of influencing directly the tumor biology. This paper reviews the evidence around the potential survival benefits of LMWHs by analyzing the suggested mechanisms and the available clinical data.