Are the effects of tamoxifen on the serum lipid profile modified by apolipoprotein E phenotypes?
GROUND: Tamoxifen has favorable effects on the serum lipid profile. It has been suggested that the apolipoprotein (Apo) E phenotype can influence serum lipid parameters; the ApoE allele 4 (ApoE4) is associated with higher total and low-density lipoprotein (LDL) cholesterol levels. The ApoE phenotype also affects lipid responses to diets or treatment with statins. However, the effect of tamoxifen on the lipid profile in different ApoE phenotypes is unknown. PATIENTS AND METHODS: In the present study, we evaluated the effects of tamoxifen on the serum lipid profile in 11 ApoE4-positive postmenopausal women with breast cancer (phenotypes 3/4 and 4/4) compared with 33 ApoE4-negative women (phenotypes 3/2 and 3/3). Serum lipid parameters [high-density (HDL), LDL and total cholesterol, triglycerides, ApoAI, ApoB and lipoprotein (a)] were measured after an overnight fast before treatment and after 3 and 12 months. ApoE isoforms were determined by isoelectric focusing of delipidated very-low-d
