Résumé : Considerable progress has been made in breast cancer treatment in Europe over the past three decades, yet survival rates for metastatic disease remain poor, underlining the need for further advances. While the use of predictive biomarkers for response to systemic therapy could improve drug development efficiency, progress in identifying such markers has been slow. The currently inadequate classification of breast cancer subtypes is a further challenge. Improved understanding of the molecular pathology of the disease has led to the identification of new targets for drug treatment, and evolving classifications should reflect these developments. Further ongoing challenges include difficulties in finding optimal combinations and sequences of systemic therapies, circumventing multidrug resistance and intra-tumor heterogeneity, problems associated with fragmentation in clinical trials and translational research efforts. Adoption of some of the strategies identified in this article may lead to further improvements in outcomes for patients with the disease.