Purpose of review: Breast cancer is a heterogeneous disease, including different subtypes with their own biology, prognosis, clinical characteristics and treatment. To date, traditional clinical and pathological determinants remain the main factors guiding treatment decision-making; however, the development of multigene assays improved the ability to predict the risk of recurrence in patients with early-stage breast cancer. These tools underwent an extensive independent validation and have already been partly incorporated into clinical practice.
Recent findings: The current article summarizes current evidence for the use of the different genomic assays in clinical practice, their characteristics and validation studies. A few studies comparing available genomic assays revealed that they provide different information with a modest correlation and that they are not interchangeable; other trials are currently ongoing in this setting.
Summary: Variability across different gene signatures may be a challenge for the optimal management of the individual patient, hence each assay should be used for the clinical setting in which it has been validated.