[A case of advanced HER2- positive gastric cancer with a partial response to molecular targeted chemotherapy (S-1+CDDP+Trastuzumab)].

A 61-year-old man was referred to our hospital because of gastric pain and weight loss.Upper gastrointestinal endoscopy revealed a superficial depressed (Type 3) tumor with pyloric stenosis.The tumor was diagnosed as tubular adenocarcinoma by pathological examination.Abdominal computed tomography showed enlarged paraaortic and No. 8a lymph nodes.The patient underwent distal gastrectomy (D0)and Roux-en-Y reconstruction.After surgery, chemotherapy combined with molecular targeted therapy (S-1+cisplatin[CDDP]+trastuzumab), based on overexpression of the HER2 protein in the primary tumor as assessed by immunostaining, was administered.After the molecular targeted chemotherapy, the carcinoembryonic antigen (CEA )levels decreased to the normal range and the enlarged lymph nodes were remarkably decreased in size. The patient is currently alive without progressive disease.