Low-Molecular-Weight Heparin in Patients With Advanced Cancer: A Phase 3 Clinical Trial

To prospectively assess whether low-molecular-weight heparin (LMWH) provides a survival benefit in patients with advanced cancer. Between December 1998 and June 2001, we performed a randomized controlled study of patients with advanced cancer. Initially, the study was double blinded and placebo controlled, with the patients receiving daily injections of 5000 U of LMWH or saline. However, because of low accrual midway through the study, the placebo injection arm was eliminated, and the study became open labeled, with patients receiving either LMWH injections plus standard clinical care or standard clinical care alone. The primary study end point was overall survival. Of 141 patients randomized to this clinical trial, 3 dropped out, leaving 138 patients. The median survival time was 10.5 months (95% confidence interval, 7.6-12.2 months) for the combined standard care and placebo groups. The median survival time for the combined LMWH arms was 7.3 months (95% confidence interval, 4.8-12.2 months). These median survival times were not significantly different (log-rank P=.46). The median survival times for the blinded and unblinded LMWH groups were 6.2 months and 9.0 months, respectively. The median survival times were 10.3 months for the blinded placebo arm and 10.5 months for the standard care arm. The rate of severe or life-threatening venous thromboembolism was 6% in the LMWH arms and 7% in the control arms. The rate of severe or life-threatening bleeding was 3% in the LMWH arms and 7% in the control arms. This trial was unable to demonstrate any survival benefit for LMWH in patients with advanced cancer.