[Complete Response with Neoadjuvant Chemotherapy and Curative Resection in a Case of Locally Advanced Gastric Cancer That Was Strongly Positive for HER2 with Multiple Liver Metastases].

As a part of community screening, a 64-year-old man underwent gastric fluoroscopy, which revealed abnormalities indicative of a type 3 tumor. Contrast-enhanced abdominal computed tomography showed advanced gastric cancer with multiple regional lymph nodes and liver metastases. Chemotherapy was initiated, and after completion of 2 courses of capecitabine (Cape)and oxaliplatin(OHP)therapy, a distalgastrectomy was performed. The response to chemotherapy was Grade 2, and the lymph node status was pN1(1/17). The patient was strongly positive for HER2; thus, 4 courses of Cape, OHP, and trastuzumab(T-mab)therapy were administered for the metastatic liver lesions, and the liver metastases shrank markedly. S5 subsegmentectomy and S7 partial resection were performed subsequently, and pathological analysis showed completely necrotic tissue. Remarkable progress has been made in chemotherapy for gastric cancer, and the use of T-mab in combination is extremely effective for gastric cancer that is strongly positive for HER2. In our patient, we resected the primary lesion and liver metastatic lesions after neoadjuvant chemotherapy. The metastatic lesion showed complete response(CR). Metastases and recurrences can even occur in patients with primary and/or metastatic lesions who show a CR. Furthermore, whether cancers that are strongly positive for HER2 are recurrent remains unknown. The patient is alive and recurrence-free after having undergone a hepatectomy.