[CURRENT PERSPECTIVE ON SYSTEMIC THERAPY FOR BREAST CANCER]

The decision to use adjuvant therapy for breast cancer takes into account tumor biology and tumor stage. Because there have been no effective predictive factors for chemotherapy, current guidelines generally recommend chemotherapy for high-risk breast cancer. Multigene assays may predict the benefit from chemotherapy. With the recognition that estrogen has an important role in the promotion and progression of hormone receptor-positive breast cancer, endocrine therapy is a principle component in the treatment of hormone-sensitive breast cancer. The endocrine treatment of breast cancer utilizes strategies that reduce or halt estrogen production, block signaling through the estrogen receptor (ER), or antagonize the ER itself. Tamoxifen has been recommended for premenopausal women with hormone receptor-positive breast cancer during the past 15 years. The value of adding luteinizing hormone-releasing hormone in premenopausal women who receive tamoxifen should be considered in the high-risk premenopausal cohort. For most women with postmenopausal breast cancer, aromatase inhibitors are recommended. The extension of treatment with endocrine treatment to 10 years could improve the prognosis of hormone receptor-positive breast cancer patients. The benefit of adjuvant trastuzumab was established for human epidermal growth factor type 2-overexpressing breast cancer patients.