The patient was a 39-year-old woman who was referred to our hospital with suspicion of locally-advanced breast cancer. After several tests, she received a diagnosis of cT4bN1M1 (liver), Stage Ⅳbreast cancer. The liver metastasis was located in S4, and was 1 cm in size. Core needle biopsy was performed on the breast tumor; the pathological diagnosis was invasive ductal carcinoma (scirrhous carcinoma), nuclear Grade (NG) 3, and HER2-positive. She received epirubicin plus cyclophosphamide (EC) followed by docetaxel (DOC) plus pertuzumab (PER) plus trastuzumab (HER). After chemotherapy, the liver metastasis and axillary lymph node metastases had disappeared on imaging findings, showing a complete response (CR), but the primary breast tumor remained, showing a partial response (PR). She underwent mastectomy and axillary lymph node dissection for local control. After surgery, no metastases including liver metastases were seen on CT. The patient is currently receiving tamoxifen and anti-HER2 therapy.