Changing the gold standard in adjuvant therapy for breast cancer:: from tamoxifen to aromatase inhibition

The introduction of third generation aromatase inhibitors [anastrozole, letrozole, and exemestane] has certainly improved outcomes in patients with early breast cancer. Although survival benefit has not been identified (except in the subpopulation of patients with lymph node positive breast cancer on the MA17 study), the primary endpoints in all studies reached statistical significance in favor of AI. The strategy can include: replacing TAM outright after diagnosis; switching from TAM to one of the aromatase inhibitors after 2-3 years; or to add an At after 5 years of TAM. DFS, recurrence, and the incidence of contra lateral breast cancer is influenced favorably with such an approach. The following issues remained unanswered: Will the OS be improved as well? Is the incidence of serious long-term side effects acceptable to our patients [osteoporosis, fractures, cognitive function and lipid profile changes]? What is the influence of chemotherapy on the effect of aromatase inhibitors? We still do not know the true role of At in HER2 positive disease. Which effect do At have in pre-menopausal women (with the use of LHRH agonists)? How long should patients after TAM be receiving At? Several of these questions will be certainly answered with the new generation of studies, but many of these questions have just been generated with these new results. (c) 2005 Elsevier SAS. All rights reserved.