[Long-Term Response of Nivolumab for Peritoneal Dissemination and Recurrent Liver Metastasis after Surgery for Perforated Gastric Cancer-A Case Report].

A 39-year-old woman was hospitalized because of lower abdominal pain and fatigue. A laboratory study indicated severe anemia(hemoglobin 2.5 g/dL). Computed tomography(CT)revealed a perforated gastric tumor and free air. Distal gastrectomy was performed as an emergency surgery. Histopathologic examination showed adenocarcinoma(moderately differentiated > poorly differentiated), and she was diagnosed as having a pT4b, pN0, pM1, pStage ⅣB tumor. Postoperatively, adjuvant chemotherapy with S-1 was administered. CT imaging 2 years after the operation showed peritoneal dissemination and liver metastasis, and XELOX therapy was initiated. Response evaluation after 3 courses was progressive disease (PD), and ramucirumab plus paclitaxel was initiated. After 5 courses, CT imaging revealed ascites and progression of peritoneal dissemination and liver metastasis; nivolumab was initiated. CT imaging after 74 courses showed peritoneal dissemination, and liver metastasis became unclear. The patient at present has responded well to nivolumab for 52 months.