Would you use first line combination immunotherapy with chemotherapy in patients with metastatic low ER/PR+ (<10%), HER2 negative breast cancer?

Low positive with 1% to 10% cells staining for ER are particularly clinically challenging, although uncommon (accounting for 2%-3% of ER-positive cancers). The first step is to make sure the IHC testing algorithm relies on accurate, reproducible assays, and clinically validated methods. Up to 20% of...