Effect of letrozole on the lipid profile in postmenopausal women with breast cancer

Hormonal therapy plays a central role in the overall treatment of breast ca ncer. Aromatase inhibitors can inhibit the aromatase enzyme system resultin g in a reduction of oestrogens. Letrozole is a non-steroidal aromatase inhi bitor that effectively blocks aromatase activity without interfering with a drenal steroid biosynthesis. The drug can significantly reduce the levels o f plasma oestrogens, which remain suppressed throughout the treatment. Data are scarce concerning the influence of these drugs on serum lipid levels. In the present study, we evaluated the effects of letrozole on the serum li pid profile in postmenopausal women with breast cancer. A total of 20 patie nts with breast cancer were treated with letrozole, 2.5 mg once daily. Afte r an overnight fast, serum lipid parameters (total cholesterol, high densit y lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, triglycerides, apolipoproteins Al, B and E and lipoprotein (a)) were measu red before treatment and at 8 and 16 weeks afterwards. A significant increa se in total cholesterol (P = 0.05), LDL cholesterol (P < 0.01) and apolipop rotein B levels (P = 0.05) in the serum, as well as in the atherogenic risk ratios total cholesterol/HDL cholesterol (P < 0.005) and LDL cholesterol/H DL cholesterol (P < 0.005) was noticed after letrozole treatment. We conclu de that letrozole administration in postmenopausal women with breast cancer has an unfavourable effect on the serum lipid profile. (C) 2001 Elsevier S cience Ltd. All rights reserved.