Low-Molecular-Weight Heparin Improves Survival Rate

Use of low-molecular-weight heparin (LMWH) to treat patients with cancer appears to reduce their rate of mortality compared with best supportive care, according to a meta-analysis of clinical trials. Researchers reported the findings at the 21^st Congress of the International Society of Thrombosis and Haemostasis (ISTH). "The pooled data from the trials showed a significant overall improvement in survival for low-molecular-weight-heparin users," says lead investigator and presenter Sylvie Laporte, PharmD, Department of Clinical Pharmacology, University Hospital of St-Etienne, Saint-Etienne, France.

The investigators conducted an electronic search of major research databases as well as a manual search of medical conference proceedings. They looked for randomised clinical trials (RCTs) comparing LMWH with placebo or no treatment in cancer patients, and trials comparing LMWH with other vitamin K antagonist (VKA) cancer treatments in patients with venous thromboembolism (VTE). The researchers used standard statistical models and practices to analyse the pooled data and used overall survival at the end of follow-up as their endpoint. They selected 10 RCTs comparing LMWH with best supportive care, six trials with LMWH versus placebo/no treatment (912 patients, 2 RCTs pending), and four trials with LMWH versus VKA in cancer patients with VTE (1,120 patients). Overall survival rate with LMWH was significantly higher than with best supportive care ([P =.02), with an overall hazard ratio of 0.87, which translates to a 13% reduction in mortality in the LMWR-treated patients.

"These results support the potentially beneficial effect of LMWH on cancer survival, although lack of power precludes an unequivocal conclusion concerning patients with and without VTE separately. Additional trials are required to define the tumour types and disease stages most likely to show a real survival benefit," the authors conclude.