Our study is evaluating the benefit of anthracyclines in HR positive HER2 negative node negative breast cancer. We performed a post-hoc analysis from the TAILORx study evaluating taxanes and cyclophosphamide versus T-AC, taxanes with anthracycline and cyclophosphamide, and evaluated which patients, based on their recurrence score, may derive a benefit from additional anthracylcines.

What was the study design?

This was a post-hoc analysis from the TAILORx study. We evaluated patients who received TC versus T-AC and wanted to better understand survival based on their recurrence score in terms of anthracycline benefit.

What were the results of this study?

We demonstrated that with recurrence scores at 31 or greater there is an improvement in 5-year distant recurrence free interval, distant recurrence free survival and recurrence free survival as well as a trend towards significance of improved overall survival in patients receiving anthracyclines as compared to patients who just received taxanes and cyclophosphamide. We also demonstrated that this benefit is primarily in tumours that are 2cm or greater and that this benefit increases with increasing recurrence scores above 31.

What is the significance of these results?

This really places anthracyclines in a newer context within the thought of recurrence score and how we may better identify patients who would benefit from an anthracycline. Previous data showed that nodal status may not be the best biomarker to understand the benefit of anthracyclines in this patient population and so we were looking to see if recurrence score would give us better results. We think that anthracyclines could be considered in patients with high recurrence scores in the treatment of node negative HR positive breast cancer but certainly this needs to be balanced out with the risk of anthracyclines, including cardiotoxicity and late development of haematologic malignancies.