ESR1 and neoplasm: Since the tumor was ER(+), PR(−), and HER2(+), the patient received four 21-day cycles of intravenous docetaxel (75 mg/m2), intravenous cyclophosphamide (600 mg/m2), and intravenous trastuzumab 8 mg/kg (loading dose) on day 1 followed by 6 mg/kg every 3 weeks to complete a full year of intravenous treatment.