ERBB2 and ductal breast carcinoma in situ: Compared with the SeB group, patients in the SIB group were significantly more likely to present with T2–3 stage, N1–3 stage, ductal carcinoma in situ component, lymphovascular invasion, and to have undergone neoadjuvant or adjuvant chemotherapy, anti-HER2 targeted therapy, and endocrine therapy.