Complete Response Obtained with S-1 Plus CDDP Therapy in a Patient with Multiple Liver Metastases from Gastric Cancer

A 58-year-old woman with advanced gastric cancer underwent total gastrectomy in May 2012. The histological diagnosis was poorly differentiated adenocarcinoma, cT4a (SE), pN1, cM0; fStage IIIA. Chemotherapy by S-1 was started after surgery. Six months after the operation, two metastatic nodules were noticed on the liver. Therefore, the chemotherapy was switched to S-1 plus cisplatin (CDDP) in November 2012. TS-1 (80 mg/body) was administrated from day 1 to 21 followed by 14 days rest as one course. CDDP (70 mg/body) was infused on day 1. After 3 courses of this combination chemotherapy, remarkable diminution of the metastatic lesions on CT images was observed. Because of the adverse event of Grade 2 nausea, the patient was forced to discontinue chemotherapy. The patient underwent partial resection of the liver (Hr-0: S8, S7) at 1 year after the first operation. The resected specimens showed no sign of malignancy, although uneven fatty deposition was observed more frequently than in the surroundings, and designated as histologically complete response (CR). The patient has been alive 30 months after the second operation without any recurrent sites. Thus, combined use of peroral S-1 and CDDP should be recommended for multiple liver metastases after gastrectomy.