Personalized treatment of early-stage breast cancer: present concepts and future directions.

Breast cancer is the most common malignancy in women. Effective loco-regional as well as systemic treatment options have rendered breast cancer a curable disease for the vast majority of early-stage patients. Considering tumor biology and clinical outcomes, breast cancer is a very heterogeneous disease. With the recent understanding of distinct molecular sub-types, the era of "one size fits all" therapy concepts has passed and a new era of personalized therapy concepts has started. This review will focus on recent advances in personalized treatment of early-stage breast cancer, with a particular interest in tumor biology-guided treatment decisions. It will also highlight how carefully molecular tests need to be methodologically and clinically validated before they can be applied for clinical decision making.