[Trastuzumab Combination Chemotherapy Followed by R0 Resection for Locally Advanced Human Epidermal Growth Factor Receptor 2-Positive Gastric Cancer-A Case Report].

A man in the 60s visited our hospital with the complaints of epigastralgia and weight loss. Following an investigation, he was diagnosed with human epidermal growth factor receptor 2(HER2)-positive gastric cancer with invasion to the pancreas (T4b[pancreas], N2, M0, Stage ⅣA[Union for International Cancer Control 8th edition]). Preoperatively, he was administered a chemotherapeutic regimen of S-1 and cisplatin plus trastuzumab. After 2 courses of chemotherapy, computed tomography revealed invasion to the abdominal wall and pyloric stenosis; however, invasion to the pancreas was obscured, and the lymph node metastases had shrunk. He underwent laparoscopic gastro-jejunostomy. After 4 courses of chemotherapy, his condition was considered stable. A laparoscopic distal gastrectomy was performed together with resection of the abdominal wall invasion. The pathological stage was pT4b(abdominal wall), pN0, M0, Stage ⅢA, and R0 resection was achieved. The patient was administered 4 courses of adjuvant capecitabine plus oxaliplatin therapy and 4 courses of capecitabine monotherapy. He has been followed-up for 1.5 years since the curative resection and has not developed recurrences. This case suggests the usefulness of multimodal therapy for locally advanced gastric cancer.