[A Case of Advanced Gastric Cancer Who Experienced Multiple Immune-Related Adverse Events with Nivolumab and SOX...

A 59-year-old woman who has HER2-negative advanced gastric cancer with peritoneal dissemination was treated with nivolumab plus SOX therapy as primary treatment, and hemorrhagic cystitis occurred on the 28th day after the 6 courses. On the 21st day after the 7 courses, right knee arthralgia appeared, and on the 26th day, she was admitted to the hospital due to a fever of 39℃ and anorexia. After admission, frequent diarrhea occurred and new symptoms of neck pain and left knee arthralgia appeared. Abdominal CT showed increased fatty tissue density around the sigmoid colon, and wall thickening and contrast enhancement of the mucosal surface of the bladder. Lower gastrointestinal endoscopy revealed the diffuse redness and erosions in some areas, and lymphocytic infiltration in the epithelium of the crypts was seen in biopsy from the erosions. The hemorrhagic cystitis was aseptic pyuria. Therefore, we suspected that the series of symptoms were immune-related adverse events(irAE)and started prednisolone 50 mg(1 mg/kg/day), which quickly relieved the diarrhea, cystitis and arthralgia. As a result, the patient was diagnosed as having irAE. We report a case of advanced gastric cancer who experienced multiple irAE with nivolumab plus SOX therapy, with some discussion of the literature.