How would you council a woman in her 50s with Stage I HR+/HER2- breast cancer with a high risk Mammaprint but intermediate OncotypeDx regarding adjuvant chemotherapy?  

This is a challenging question to address without more details. The first question is why were two different assays run on the tumor? Also, in the context of the TAILORx data which demonstrated a lack of benefit from chemotherapy for postmenopausal women with Oncotype DX recurrence scores 25 or less...

I agree that in a clinical low-risk situation (as appears to be in this case - Stage I, HR+/HER2-negative, but grade is not given), that Oncotype would be the most clinically applicable and evidence-based assay based on the TAILORx trial results, and an RS of 25 or less would be associated with mini...

In this case, no chemotherapy is warranted. The clinical utility of Mammaprint is to identify clinical high risk patients who can safely skip chemotherapy. It has not been shown to identify clinical low risk patients who benefit from chemotherapy. The low risk cutoff (10% or less recurrence risk) fo...