ESR1 and ductal breast carcinoma in situ: Of these, one was classified as pT1a (IDC, 2 mm, G2, ER 100%, PR 100%, HER2-negative, Ki-67 5%), one as pT1b (IDC, 6 mm, G3, ER 100%, PR 5%, HER2-negative, Ki-67 55%) pN0sn and one as HR-DCIS.