Most studies for identifying biomarkers for oestrogen receptor-α (ERα)-positive breast cancer have been performed using material from consecutive series of patients treated with tamoxifen. Consequently, the predictive value of any biomarker identified is confounded by its prognostic value. In this Review, the authors discuss how different biomarkers might enable the prediction of broad endocrine or agent-specific resistance.
- Karin Beelen
- Wilbert Zwart
- Sabine C. Linn