The effects on lipid serum levels of a 2-year adjuvant treatment with exemestane after tamoxifen in postmenopausal women with early breast cancer

BACKGROUND: The third-generation aromatase inhibitor exemestane represents a new development in the treatment of estrogen-positive breast cancer. The aim of this study was to evaluate the effects on lipid profile and body composition of the shift from tamoxifen to exemestane. METHODS: After 2-3 years of tamoxifen adjuvant treatment, 68 postmenopausal women were randomly assigned to either continue tamoxifen 20 mg/day (n = 35) or to switch to exemestane 25 mg/day (n = 33). RESULTS: No significant changes in lipid profile were found in patients continuing on tamoxifen. In the exemestane group, serum HDL-cholesterol (HDL-C) and triglycerides (TG) decreased significantly (p < 0.01) and serum LDL-cholesterol (LDL-C) increased significantly (p < 0.05) with respect to baseline. The difference between the two groups was significant. Moreover, in the exemestane group, fat mass (FM) and fat-free mass (FFM) showed an opposite trend, which determined a progressive and significant increase in the FFM/FM ratio. CONCLUSION: This study shows that the choice of first-line treatment or adjuvant therapy for breast cancer should also take the individual lipid and body composition profile into account