Top Line: NSABP B-51 is the trial on every rad onc’s mind when seeing a woman who has achieved a complete pathologic nodal response (ypN0) after neoadjuvant therapy for breast cancer.
The Study: As a reminder, B-51 randomized patients with initial node positive disease who had a pathologic complete response to neoadjuvant systemic therapy to receive adjuvant regional nodal irradiation or not. The initial results were presented this weekend at the San Antonio Breast Cancer Symposium. Spoiler alert (though really who’s surprised at this point?): there were fewer recurrences than planned for precluding sophisticated statistical analyses. And yet a simple look at the numbers showed no meaningful absolute difference outcomes with or without RNI for women with ypN0 breast cancer. Across 1556 evaluable enrollees, the primary endpoint of freedom from invasive breast cancer recurrence at 5 years was 93% with and 92% without RNI. What’s more, freedom from distant recurrence was 93% either way and overall survival 94% either way. We await full reporting as well as long-term follow up, but at this point it seems that many patients with no lymph node involvement after neoadjuvant systemic therapy may be able to omit adjuvant RNI.
TBL: Initial abstract results of NSABP B-51 report no significant difference in treatment outcomes when RNI is omitted in patients who have a complete response in regional nodes after neoadjuvant systemic therapy. | Mamounas, SABCS 2023
The Study: As a reminder, B-51 randomized patients with initial node positive disease who had a pathologic complete response to neoadjuvant systemic therapy to receive adjuvant regional nodal irradiation or not. The initial results were presented this weekend at the San Antonio Breast Cancer Symposium. Spoiler alert (though really who’s surprised at this point?): there were fewer recurrences than planned for precluding sophisticated statistical analyses. And yet a simple look at the numbers showed no meaningful absolute difference outcomes with or without RNI for women with ypN0 breast cancer. Across 1556 evaluable enrollees, the primary endpoint of freedom from invasive breast cancer recurrence at 5 years was 93% with and 92% without RNI. What’s more, freedom from distant recurrence was 93% either way and overall survival 94% either way. We await full reporting as well as long-term follow up, but at this point it seems that many patients with no lymph node involvement after neoadjuvant systemic therapy may be able to omit adjuvant RNI.
TBL: Initial abstract results of NSABP B-51 report no significant difference in treatment outcomes when RNI is omitted in patients who have a complete response in regional nodes after neoadjuvant systemic therapy. | Mamounas, SABCS 2023