Would you offer OFS/AI alone or with the addition of chemotherapy in a premenopausal female with ER+/PR+ breast cancer with microscopic LN involvement and an OncoTypeDx score <11?

Oncotype recurrence score (RS) testing provides both prognostic and predictive information. This is a tumor with a low score and has an excellent prognosis, regardless of what treatment is given. Chemotherapy would not be necessary in an endocrine-sensitive tumor such as this.

The issue, of course, comes up in this delicate situation because RxPONDER initially randomized patients with LN micrometastasis until about halfway in the trial, then excluded these patients. Still, the biology of disease and minimal impact of a micrometastasis is very much no different from a node negative tumor with a low RS.

In the second part about endocrine therapy choice, any absolute benefit from adding OS would depend on the risk of recurrence from this tumor a...