[A Case of Effective Disease Control of Advanced Gastric Cancer with Distant Lymph Node Metastases Following Nivolumab Treatment].

A 66-year-old man was diagnosed with advanced gastric cancer(L, Less, Type 2, T4a[SE], N2, M1[LYM], H0, P0, cStage Ⅳ)and received treatment with S-1/cisplatin as first-line chemotherapy. This treatment resulted in partial response(PR) after 3 months, with reduction in the sizes of metastatic lymph nodes surrounding the pancreatic head and paraaortic lesion. However, the sizes of metastatic lymph nodes increased after 7 months of chemotherapy. Ramucirumab/nab-paclitaxel was then administered as second-line chemotherapy, and the diameter of the metastatic lymph nodes subsequently decreased after 4 months of the regimen. However, progressive disease was observed at 7 months, and blood transfusion was required because of bleeding from the primary gastric tumor. Therefore, nivolumab was initiated as third-line chemotherapy 14 months after the first treatment. After nivolumab administration, a 28% reduction in metastatic lymph nodes was achieved within 3 months, together with the regression of the primary gastric tumor and improvement in anemia within 6 months. PR was achieved after 12 months of nivolumab administration, and effective disease control was maintained for 16 months without any adverse reaction to nivolumab.