Tamoxifen and cardiac risk factors in healthy women: Suggestion of an anti-inflammatory effect.

-Tamoxifen reduces the incidence of breast cancer in women at risk for that disease. Because heart disease is the leading cause of death in women and because tamoxifen is also associated with venous thrombosis, an improved understanding of the association of tamoxifen with cardiovascular disease risk factors is required. In 111 healthy women at a single center, who were participating in a randomized double-blind breast cancer prevention trial, the 6-month effects of oral tamoxifen (20 mg/d) compared with placebo on factors related to inflammation, hemostasis, and lipids were studied. Tamoxifen was associated with reductions of 26% in median C-reactive protein, 22% in median fibrinogen, and 9% in cholesterol (all P:<0.01 compared with placebo). There were no differences in treatment effects on factor VII coagulant activity, fragment 1-2, and triglycerides. In secondary analyses, the effect of tamoxifen on C-reactive protein was larger in postmenopausal women and in women with higher waist-to-hip ratios. The effect on fibrinogen was larger in women with higher baseline cholesterol. Tamoxifen demonstrated effects on inflammatory markers that were consistent with reduced cardiovascular risk. These findings are in contrast to recent reports of increased C-reactive protein associated with postmenopausal estrogen. The potential for beneficial cardiovascular effects of tamoxifen in healthy women is suggested.