“Breast Cancer Index (BCI) and Prediction of Benefit from Extended Aromatase Inhibitor (AI) Therapy (tx) in HR+ Breast Cancer: NRG Oncology/NSABP B-42. Trastuzumab Plus Endocrine Therapy or Chemotherapy as first-line Treatment for Metastatic Breast Cancer with Hormone Receptor-Positive and HER2-positive: The Sysucc-002 Randomized Clinical Trial. “