Systemic treatment of breast cancer. Two decades of progress.

Over the past 20 years we have witnessed the emergence of a new generation of aromatase inhibitors as valuable antiestrogens in the management of both advanced and early-stage breast cancer. In addition, the list of cytotoxic chemotherapeutic agents useful in the control of breast cancer has grown considerably. The emergence ofanthracyclines was a major chemotherapeutic step forward in the 1980s, and the taxanes have clearly been the agents with the greatest impact on breast cancer treatment over the past decade. The end of the past 2 decades has been characterized by a greater understanding of the molecular biology of breast cancer, rational drug design, and the development of agents that disrupt specific cellular targets and pathways. The development of better prognostic and predictive assays that employ a panel of genes involved in the malignant and metastatic phenotype promises to allow clinicians to better select patients who could forgo adjuvant chemotherapy. Finally, adjunctive and supportive therapy of breast cancer has evolved substantially over the past 20 years. This review will highlight some of the landmark accomplishments during this time, and offer a glimpse at where we might be 20 years from now.