Adjuvant systemic therapy in breast cancer: quo vadis?

The premise that breast cancer (BC) has a tendency toward early systemic dissemination, together with empirical findings showing that drugs given after breast tumor surgery improve outcome, led to the development of systemic adjuvant therapy. This strategy, which started more than 50 years ago, revolutionized BC treatment and improved patient outcome in a substantial way. However, in recent years, several large trials that incorporated new systemic treatments in the adjuvant setting of BC failed to demonstrate a benefit. In the present review, we discuss the progress made in the adjuvant treatment of BC in the past decade, the possible reasons for the recent failures, and practical strategies that may be incorporated in the design of future trials.