Changes in serum lipid and lipoprotein levels in postmenopausal patients with node-positive breast cancer treated with tamoxifen

Tamoxifen has been used for a long time as an adjuvant hormonal treatment in breast cancer patients. We studied 62 newly diagnosed postmenopausal women, aged 50-79 years, with node-positive breast cancer and receiving adjuvant tamoxifen (20 mg per day). Total serum cholesterol, triglycerides, HDL-cholesterol, LDL-cholesterol, VLDL-cholesterol, apo AI, apo AII, apo a and Lp(a) were determined before the surgery and 3, 6, 9, 12 and 24 months after starting tamoxifen treatment. Tamoxifen significantly reduced total serum cholesterol (6.13 +/- 1.20 mmol/L vs 5.21 +/- 1.05 mmol/L) (P <0.01), LDL-cholesterol (3.72 +/- 0.70 mmol/L vs 2.93 +/- 0.51) (P <0.01) and Lp(a) (0.11 +/- 0.07 g/L vs 0.02 +/- 0.01 g/L) (P <0.01). There were no changes in triglycerides or HDL-cholesterol serum levels during tamoxifen treatment. The results indicate that an additional beneficial effect of adjuvant tamoxifen therapy may be that it decreases cardiovascular risk in such patients.