Progress in systemic adjuvant therapy of early-stage breast cancer.

Despite major improvements in the treatment of early-stage breast cancer over the past 15 years, many controversies exist surrounding the optimal adjuvant therapies for these patients. Adjuvant chemotherapy has been demonstrated to reduce recurrence and improve mortality, but questions persist as to what is the optimal regimen and how much adjuvant therapy should be administered. Among the adjuvant chemotherapy issues that remain controversial are the role of the taxanes and the optimal number of adjuvant chemotherapy treatment cycles. In the realm of adjuvant endocrine therapy, the early results of the Anastrozole, Tamoxifen and Combination (ATAC) trial have led to confusion as to how best to treat postmenopausal patients with estrogen receptor-positive, early-stage breast cancer. Clinicians are faced with the decision of choosing between tamoxifen and anastrozole. The enthusiasm for so-called targeted therapies, such as trastuzumab, in patients with metastatic disease, is now being carried over into the adjuvant setting. Multiple clinical trials around the world are evaluating the potential benefit of adding trastuzumab to chemotherapy in patients with HER2-positive, early-stage breast cancer. In the United States, clinicians are faced with many decisions on how to optimally treat patients with early-stage breast cancer. Evidence-based treatment guidelines such as those developed by the National Comprehensive Cancer Network (NCCN) provide a useful algorithm for assisting in making treatment decisions. It is hoped that, in the next few years, the results of ongoing clinical trials now underway will lead to further improvements in the outcome of patients with early-stage breast cancer.