Would you treat a patient with cT2 ER+/HER2+ breast cancer with neoadjuvant HER2 directed therapy if HER2 positivity is group 3?   

If the case remains group 3 after an independent retesting with FISH and IHC as recommended by ASCO CAP guidelines, then the official recommendation is to treat it as HER2+ and use anti HER2 neoadjuvant therapy. However, some of these tumors are more luminal B than HER2 enriched on gene expression t...