Genomic Testing to Guide Local Therapy Decisions in Hormone Receptor-Positive Breast Cancer

To explore how genomic testing has changed local therapy decision-making, specifically surgical timing and opportunities for de-escalation of radiation therapy in hormone receptor-positive, HER2-negative (HR + HER2-) breast cancer.

Randomized trials have shown that genomic tests can be used to guide systemic therapy decision in HR + HER2- breast cancer, with a significant proportion of patients not receiving benefit from chemotherapy. Emerging data suggests that the use of genomic testing on core needle biopsy can also predict response to preoperative therapy and guide choices between neoadjuvant treatments when preoperative therapy is needed, especially in women with limited nodal disease that may not otherwise require chemotherapy. Further, genomic tests can stratify which patients are at the lowest risk for locoregional recurrence and may be candidates for omission of radiation therapy.

Genomic testing can guide surgical timing and opportunities for selecting the lowest-risk patients for omission of radiation therapy.