From the Department of Medical Oncology and Breast/Gynecologic Cancer Center, University Hospital Berne, and the International Breast Cancer Study Group, Coordinating Center, Berne, Switzerland
Authors’ disclosures of potential conflicts of interest are found at the end of this article.
Address reprint requests to Stefan Aebi, MD, Department of Medical Oncology and Breast/Gynecologic Cancer Center, University Hospital Berne, Inselspital PT2C, Berne CH-3010, Switzerland; e-mail: stefan.aebi{at}insel.ch
Overview: Endocrine therapy is an essential component of the adjuvant therapy for women with operable breast cancer that expresses estrogen and/or progesterone receptors. For premenopausal women, 5 years of tamoxifen continues to be the standard adjuvant therapy. The suppression of ovarian function is as effective as chemotherapy without hormone therapy. However, the importance of ovarian function suppression in addition to tamoxifen is unknown and is being investigated in a clinical trial. Aromatase inhibitors as monotherapies are ineffective in premenopausal women; these agents are being investigated in combination with ovarian function suppression. In postmenopausal women, 5 years of adjuvant tamoxifen is inferior to the use of third-generation aromatase inhibitors. It is not clear whether 5 years of aromatase inhibitors represents the optimum therapy duration or whether sequential therapies with tamoxifen and aromatase inhibitors are superior; patients with a high risk of early relapse might profit from upfront therapy with an aromatase inhibitor. Patients who are in remission after 2 to 5 years of adjuvant tamoxifen should be offered an aromatase inhibitor. Breast cancers in men usually express estrogen receptors and respond to endocrine therapy. Tamoxifen is the standard adjuvant therapy; aromatase inhibitors may be less effective in the presence of testicular function, and other endocrine agents should be investigated.
