Ax: axillary lymph node dissection; BMI: body mass index; Bp: partial mastectomy; DCIS: ductal carcinoma in situ; DTX: docetaxel; FEC: fluorouracil, epirubicin hydrochloride, and cyclophosphamide; FISH: fluorescence in situ hybridization; HER2: anti-human epidermal receptor 2; LCIS: lobular carcinoma in situ; Ly: lymph duct invasion; NAC: neoadjuvant chemotherapy; Per: pertuzumab; SN: sentinel lymphadenectomy; Tr: trastuzumab; v: vascular invasion. This evidence concerns the gene ERBB2 and ductal breast carcinoma in situ.