We present the case of a 55-year-old-woman who was diagnosed with left breast cancer, and underwent a left mastectomy and left axillary lymph node resection. The histopathological examination indicated scirrhous carcinoma and lesser papillotubular carcinoma[estrogen receptor-negative (ER-), progesterone receptor-negative(PgR-), and human epidermal growth factor receptor 2-positive, grade 3 (HER2, 3+)] with lymph node metastases. Adjuvant chemotherapy consisting of epirubicin and cyclophosphamide (EC) followed by paclitaxel was administered. During the therapy, the patient noticed a mass on her left chest wall. It was diagnosed as a locally recurrent tumor. A computed tomography (CT) scan indicated supraclavicular lymph node metastasis. The patient underwent radiotherapy and was administered chemotherapy with TS-1 and trastuzumab. Brain metastases were found 24 months postoperatively, and the patient underwent surgery and wholebrain radiotherapy. After these, systemic capecitabine and trastuzumab chemotherapy was administered. The therapy was subsequently changed to capecitabine and lapatinib. There have been no subsequent metastatic tumors, and good control has been achieved for a long time after the detection of brain metastases.