ESR1 and invasive ductal breast carcinoma: A 50-year-old woman presented with the American Joint Committee on Cancer (AJCC) eighth edition anatomic stage IIIA invasive ductal carcinoma of the left breast, cT2N1M0, grade 2, estrogen receptor (ER)-positive, progesterone receptor (PR)-positive, and human epidermal growth factor receptor 2 (HER2)-negative.