Individualization of therapy using Mammaprint: from development to the MINDACT Trial.

To date, most treatment decisions for adjuvant chemotherapy in breast cancer are sed on conventional clinicopathological criteria. Since breast cancer tumors with similar clinicopathological characteristics can have strikingly different outcomes, the current selection for adjuvant chemotherapy is far from accurate. Using high-throughput microarray analysis, a 70-gene signature was identified which can accurately select early stage breast cancer patients who are highly likely to develop distant metastases, and therefore, may benefit the most from adjuvant chemotherapy. This review describes the development of the 70-gene profile (Mammaprint), its retrospective validation and feasibility studies, and its prospective validation in the large adjuvant MINDACT (Microarray In Node-negative Disease may Avoid ChemoTherapy) clinical trial.