Serum cholesterol reduction with tamoxifen.

The serum cholesterol levels of 123 consecutively and newly diagnosed women with Stage I and II breast cancer taking tamoxifen were compared with a control group of 81 consecutively newly diagnosed women with Stage I and II breast cancer who were not taking a hormonal treatment or supplement. Other factors that were evaluated were age, menopausal status, tumor size, weight, height, Quetelet index, and smoking and alcohol intake history. The mean cholesterol change in patients on tamoxifen (34.2 +/- 3.6 mg/dl) was significantly greater than controls (1.0 +/- 4.1 mg/dl) (P less than 0.001). Serum cholesterol fell by more than 10 mg/dl in 72.9% of women on tamoxifen vs. 35.1% of controls and by more than 40 mg/dl in 39.9% of women on tamoxifen vs. 12.6% of controls. Multivariate analysis revealed that tamoxifen administration (P less than 0.0001), initial cholesterol level (P = 0.001), and age (P = 0.04) were significant factors in producing a decrease in serum cholesterol. The administration of tamoxifen as adjuvant therapy to women with newly diagnosed breast cancer resulted in a significant fall in serum cholesterol. This effect of tamoxifen on the serum cholesterol may prove to be an additional benefit in the form of reduced cardiovascular risk in these women.