[A case of HER2-positive and AFP-producing gastric cancer successfully treated by trastuzumab/docetaxel/S-1 combination therapy].

A 74-year-old man was referred to our hospital because of abdominal distension. Upper gastrointestinal endoscopy revealed advanced gastric cancer and early gastric cancer. HER2-positive and AFP-producing gastric cancer with peritonitis carcinomatosa showing no indication for operation was diagnosed by histopathological and radiological examinations. He was treated with trastuzumab, docetaxel, and S-1 combination chemotherapy. At the end of the second course of therapy, the primary lesion was remarkably decreased in size and was associated with a significant decrease in serum AFP level. No serious adverse events occurred except for grade 3-4 leukopenia and neutropenia. We carried out eight courses of chemotherapy. Trastuzumab, docetaxel, and S-1 combination chemotherapy promise to be one of the effective treatments for HER2-positive and AFP-producing gastric cancer that have no indication for radical cure excision.