Breast cancer: achievements in adjuvant systemic therapies in the pre-genomic era.

In recent decades, the use of adjuvant systemic therapies for early breast cancer has increased extensively and has most likely contributed to the decline in breast cancer mortality observed in the U.S. and in some European countries. The last few years have witnessed accelerated progress in the treatment of early breast cancer, with the introduction of taxanes and aromatase inhibitors and, most impressively, trastuzumab to the adjuvant portfolio. When compared with anthracycline-based regimens, the addition of taxanes to treatments for patients with node-positive breast cancer has shown benefits in disease-free survival and, in some trials, in overall survival; however, these drugs are not yet universally accepted as standard treatment. Significant improvements in endocrine therapy in both pre- and postmenopausal patients with endocrine-responsive disease have been made. In the postmenopausal setting, aromatase inhibitors have shown superiority over tamoxifen in a direct comparison upfront or when given in sequence after 2-5 years of tamoxifen, but the optimal modality of administration remains unclear. For premenopausal women, ovarian function suppression with luteinizing hormone-releasing hormone analogues combined with tamoxifen has generated similar results to cyclophosphamide, methotrexate, 5-fluorouracil (CMF)-based regimens. Recently, trastuzumab has had a dramatic impact on the evolution of human epidermal growth factor receptor 2 (HER-2)-positive early breast cancer treated with standard adjuvant modalities; specifically, relapses, including distant relapses, have been halved. In this review, we summarize these main achievements, discuss the currently available adjuvant treatment options for breast cancer patients, and emphasize the need for more efficient translational research to improve individual treatment tailoring.