Can low-molecular-weight heparins improve outcome in patients with cancer?

Patients with cancer who experience a thrombotic episode have a greater mortality rate than those without thromboembolic complications. VTE appears to be a more aggressive disease in patients with cancer, who often have a greater thrombus burden than cancer-free patients. An increased risk of VTE associated with certain tumour types, such as ovarian cancer, may be linked to overexpression of coagulation proteases. Retrospective trial data suggest that LMWHs prolong survival in some cancers. LMWHs are effective both in the prevention and treatment of thromboembolic disease in patients with cancer and this may be their most important effect, contributing to an improved outcome. They may also act by inhibiting coagulation proteases, which affect tumour biology or by a direct effect on malignant cells. A prospective trial to investigate the effect of long-term treatment with the LMWH dalteparin on survival of patients with advanced cancer is currently being evaluated.