Prognostic and predictive indicators in early-stage breast cancer and the role of genomic profiling: Focus on the Oncotype DX® Breast Recurrence Score Assay

Although useful prognostic and predictive insights can be gained from patient and tumour characteristics in early-stage breast cancer, it is not always straightforward to predict the likely risk of recurrence for each individual patient following breast surgery. One of the most difficult challenges faced by clinicians is identifying patients who may benefit most from adjuvant chemotherapy, and distinguishing these cases from those where endocrine therapy may be sufficient for cure. Genomic tests such as the Oncotype DX® Breast Recurrence Score® Assay have been developed to provide a robust and clinically validated assessment of a patient's individual tumour signature. The Oncotype DX Assay is included in treatment guidelines for estimating both the risk of distant recurrence and predicting adjuvant chemotherapy benefit for early-stage breast cancer patients with human epidermal growth factor receptor 2-negative, oestrogen-receptor positive, and axillary lymph node negative or positive (1-3 positive nodes) disease. In this article, we review unmet needs for prognostication and prediction in early-stage breast cancer, and consider how the information provided by the Recurrence Score is complementary to that gained from the assessment of more traditional clinicopathologic criteria. Routine use of the assay in clinical practice, limitations and possible future directions are also discussed.