Aromatase inhibitors in the treatment of early and advanced breast cancer.

The third generation aromatase inhibitors anastrozole, exemestane, and letrozole have been compared with tamoxifen and other endocrine therapies in several studies in early and advanced breast cancer. These studies are reviewed in this report. Based on the available evidence, the panel recommends that adjuvant treatment with tamoxifen for 5 years should no longer be considered as the sole standard but that a third-generation aromatase inhibitor should be used either alone or in a sequence with tamoxifen in the adjuvant treatment of postmenopausal women with hormone-receptor-positive breast cancer. Third generation aromatase inhibitors may be considered as the first line therapy of hormone-receptor-positive advanced breast cancer in postmenopausal women, and they may also be used for preoperative therapy of breast cancer.