There has been significant improvement in outcome from breast cancer over the past 2 decades, with 5 year survival in several countries now approaching 90%. A major contributor to this improvement has been due to the use of the predictive biomarkers ER and HER2 to guide the use of effective targeted therapies. However, there are still groups of patients with breast cancer who lack targeted therapeutic approaches such as those with “triple negative breast cancers” and also patients who despite tumour expression of ER or HER2 positivity, may not respond or develop resistance to targeted therapies.
It is therefore a very active area of research to identify new predictive and prognostic biomarkers in breast cancer – a PubMed search for the terms “breast cancer biomarker” reveals more than 30 000 hits. Furthermore, new technologies, such as massively parallel/ next generation sequencing (MPS/NGS) also bring hope of identifying novel therapeutic targets highlighted by dramatic advances in therapeutic targets in other malignancies such as lung cancer and melanoma. Nonetheless, despite these efforts, there are only a handful of biomarkers in routine breast cancer clinical practice. This lecture will explore reasons for this such as lack of regulation and quality assurance in research, the lack of statistical power and bias in many research cohorts and difficulties with the clinical implementation of genomic technologies. Systemic efforts are needed to promote the translation of biomarker research into routine clinical practice in order to improve outcome for breast cancer patients.