[A case of HER2-positive advanced gastric cancer successfully treated via capecitabine, cisplatin, and trastuzumab combination chemotherapy].

We report a case of human epidermal growth factor receptor 2 (HER2) -positive advanced gastric cancer effectively treated via capecitabine, cisplatin, and trastuzumab (XPT) chemotherapy followed by curative gastrectomy. The patient was a 66- year-old man with type 2 gastric cancer in the greater curvature of the gastric angle. Biopsy revealed that the tumor was a well or moderately differentiated adenocarcinoma, and immunohistochemistry showed positive expression of HER2(3+). Chest and abdominal computed tomography(CT)showed a liver tumor 21×9 mm in size in the caudate lobe and swollen lymph nodes in the paragastric, para-aortic, and left supraclavicular regions. After 4 courses of XPT, a clinical complete response was obtained. The patient received additional 13 courses of trastuzumab and capecitabine and underwent Billroth I distal gastrectomy with D2 lymph node dissection and resection of the para-aortic and left supraclavicular lymph nodes. Liver metastasis was not detected. No residual cancer cells were found in the stomach or lymph nodes except for the left supraclavicular lymph nodes. Pathological classification according to the Japanese Classification of Gastric Carcinoma, 14 th edition, was ypT0, ypN0, ypM1(LYM), Grade 2, ypStage IV. The patient developed a post-operative anastomotic leakage that required drainage via laparotomy, but was discharged 76 days after surgery in good condition.