Effect of Raloxifene on all-cause mortality

Raloxifene, a selective estrogen receptor modulator, reduces osteoporosis and invasive breast cancer risk but increases risk for venous thromboembolism and fatal stroke in women with or at high risk for coronary heart disease. To assess the risk/benefit of raloxifene as a preventative treatment, we analyzed treatment effects on overall and cause-specific mortality.

A pooled analysis of mortality data was performed from large clinical trials of raloxifene (60 mg/day) versus placebo, including the Multiple Outcomes of Raloxifene Evaluation/Continuing Outcomes Relevant to Evista studies (7705 postmenopausal osteoporotic women followed for 4 years and a subset of 4011 participants followed for an additional 4 years; 110 deaths) and the Raloxifene Use for the Heart trial (10,101 postmenopausal women with coronary disease or multiple risk factors for coronary disease followed for 5.6 years; 1149 deaths). Cause of death was assessed by blinded adjudicators. Cox proportional hazards regression models compared mortality by treatment assignment in a pooled analysis of trial data from the Multiple Outcomes of Raloxifene Evaluation/Continuing Outcomes Relevant to Evista and Raloxifene Use for the Heart trials.

All-cause mortality was 10% lower among women assigned to raloxifene 60 mg/day versus placebo (relative hazard 0.90; 95% confidence interval, 0.80-1.00; P=.05). Lower overall mortality was primarily due to lower rates of noncardiovascular deaths, especially a lower rate of noncardiovascular, noncancer deaths.

All-cause mortality was 10% lower in pooled analyses among older postmenopausal women receiving raloxifene 60 mg/day compared with placebo, due primarily to a reduction in noncardiovascular, noncancer deaths. The mechanism whereby raloxifene might reduce the risk of noncardiovascular death is unclear.