[Advanced Gastric Cancer with Tumor Shrinkage Persisting after the Discontinuation of Nivolumab-A Case Report].

The patient was a 65-year-old man with advanced gastric cancer, cT4bN3aM1, cStage Ⅳ. The SOX therapy was administered as the primary treatment but discontinued after 9 courses because of disease progression. The PTX plus RAM therapy was then administered for 1 courses as the secondary treatment but discontinued because of the development of peritoneal dissemination, increased number of ascites, and increased number of lymph node metastases. The nivolumab(NIV)therapy was initiated as the tertiary treatment, but the patient complained of fatigue and diplopia after 2 courses. Ptosis was observed, and transaminase and creatine kinase levels were elevated. Electrocardiography showed complete right bundle branch block. The patient showed immune-related adverse events and was diagnosed with myocarditis and myasthenia gravis due to NIV. Consequently, systemic steroids were administered. Although 2 course of CPT-11 was administered as the fourth-line treatment, the treatment was discontinued upon the patient's request. Ten months after the discontinuation of chemotherapy, the disease showed no progression. The patient is being followed-up as an outpatient. Here, we reported a case of gastric cancer with tumor shrinkage after the discontinuation of NIV.