[A Case of HER2-Positive Stage IV Advanced Gastric Cancer Treated with Chemotherapy Combined with Trastuzumab].

We report a case of human epidermal growth factor receptor(HER)2 positive stage IV advanced gastric cancer successfully treated with chemotherapy combined with trastuzumab. A 50-year-old man was diagnosed with type 3 gastric cancer complicated by liver and lymph node metastases. Owing to a HER2 immunohistochemistry tumor score of 3+, we initiated capecitabine plus CDDP plus trastuzumab chemotherapy. After 6 chemotherapy courses, computed tomography showed the liver metastasis had disappeared and the paraaortic lymph nodes had shrunk. We continued the capecitabine plus trastuzumab chemotherapy, which resulted in a progression free survival of 31 months. After 38 chemotherapy courses, the primary tumor progressed; therefore, the patient underwent surgery. Chemotherapy combined with trastuzumab can allow for resec- tion of the primary tumor.