Aromatase inhibitors as adjuvant therapy in breast cancer.

The aromatase inhibitors are regarded as standard approaches to first- or second-line endocrine therapy in women with hormone-responsive metastatic breast cancer. Their efficacy and apparent lack of toxicity have led to their evaluation as adjuvant therapy. Although initial results with these agents in early breast cancer are promising, our collective long-term experience documenting tamoxifen's benefits and our uncertainty about the long-term effects of aromatase inhibitors suggest that it is too early to recommend their routine use in the adjuvant setting. However, anastrozole is also a reasonable therapeutic option in the adjuvant setting, particularly in individuals with a contraindication to tamoxifen such as those with thromboembolic disease or those who develop breast cancer while receiving tamoxifen or raloxifene (Evista) therapy. Anastrozole (Arimidex) was recently approved by the Food and Drug Administration for the adjuvant treatment of postmenopausal women with hormone-receptor-positive early breast cancer. Ongoing trials are assessing the potential role of aromatase inhibitors in the adjuvant, neoadjuvant, and preventive settings.