[A Case of Gastric Cancer Performed Curative Operation after Nivolumab]

A 69-year-old man was admitted for the severe anemia. Upper gastrointestinal endoscopy revealed type 3 gastric cancer (por1, HER2 negative)that spread from EG junction to the lesser curvature of lower gastric body. CT revealed LNs metastasis and the direct invasion to the diaphragm. We diagnosed the locally advanced gastric cancer(T4bN[+]M0, Stage ⅣA) and planed neoadjuvant chemotherapy. After 3 courses of S-1 plus CDDP therapy, serum CEA level increased. And the invasion to diaphragm was unclear although the tumor shrunk. After 3 courses of nab-PTX plus RAM therapy as the second- line, the tumor was PD. As the third-line chemotherapy, nivolumab therapy was repeated up to a total of 15 courses. As the tumor was PR, the patient underwent total gastrectomy with D2 lymphadenectomy. The histopathological examination revealed that the cancer invaded into the muscle layer without lymph nodes metastasis. The cancer was diagnosed as pT2 (MP)N0M0, Stage ⅠB. The cancer cells were EB virus positive and MSI-high. CD 8 positive T lymphocytes infiltrated into the stroma. The patient is alive 26 months without adjuvant chemotherapy. The curative operation was able to perform because the infiltrative CD8 positive T lymphocytes reactivated with nivolumab responded remarkably.