Plasma lipids and lipoprotein alterations in tamoxifen-treated breast cancer women in relation to the menopausal status.

Plasma lipids and lipoprotein profiles were monitored in 72 postmenopausal and 29 premenopausal breast cancer women who were treated with tamoxifen (20 mg twice a day) for 6 months. The levels of total and free cholesterol and LDL cholesterol were markedly (P < 0.001 for each) decreased in 3 and 6 month tamoxifen-treated postmenopausal women than the baseline values of untreated breast cancer patients. On the contrary, plasma ester cholesterol, triglycerides, VLDL and HDL cholesterol levels were increased significantly in these patients. In the case of premenopausal women the lipid lowering potential of tamoxifen was markedly retarded. These results indicated that tamoxifen - treatment was more beneficial and estrogenic in postmenopausal women's lipids. In premenopausal breast cancer women, tamoxifen was antiestrogenic and less beneficial. Hence, the difference in plasma lipids and lipoprotein content was no greater among those receiving tamoxifen and baseline values of premeno - pausal women. These results indicate that tamoxifen-treatment has a more beneficial effect in postmenopausal women, with a likely reduction in cardiovascular disease, than in premenopausal subjects.