Letters Section Editor: Robert M. Golub, MD, Senior Editor.
In Reply: Dr Chlebowski raises important points about bone loss management and lipid status during adjuvant endocrine therapy.1,2 The lipid profiles associated with aromatase inhibitor use that Chlebowski cites were measured over 12 weeks.3 The lipid data collected in the MA.17 trial, which compared letrozole to placebo in women who had completed 5 years of tamoxifen, did not show more hypercholesterolemia in those women assigned to receive letrozole, but no favorable effect of letrozole on either HDL cholesterol or triglyceride levels was observed over 3 years in the lipid substudy of this trial.4 Further, there was a small excess of cardiac events associated with aromatase inhibitor therapy in the Breast International Group 1-98 (BIG 1-98) and Intergroup Exemestane Study (IES) trials, and this is not clearly related to lipid status.2 Thus, while I agree that the bone and lipid adverse effects associated with aromatase inhibitors are likely to be manageable, further follow-up is necessary. Other than the Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial, the median follow-up for the other major trials is 3 years or less.
Come SE. Aromatase Inhibitors and Breast Cancer Treatment—Reply. JAMA. 2006;296(6):651. doi:10.1001/jama.296.6.651-b