A Case of Long-Term Survival with Recurrent Liver Metastases from Gastric Cancer Treated with Nivolumab.

Introduction: Improvements in overall survival from advanced gastric cancer have recently been reported with nivolumab. However, few reports have described long-term survival after discontinuing treatment.

Case Presentation: A 67-year-old man diagnosed with advanced gastric cancer and abdominal aortic aneurysm initially underwent distal gastrectomy with D2 dissection. Histological examination revealed tub2 and T2N1M0 stage IIA. One month later, endovascular aneurysm repair was performed. Six weeks after gastrectomy, adjuvant chemotherapy with S-1 was started. Six months later, liver metastases were identified and liver segments S1 and S7 were resected. S-1 and oxaliplatin were added postoperatively, but multiple liver metastases recurred. Paclitaxel and ramucirumab, irinotecan, and docetaxel were administered. Liver metastases showed a temporary reduction in size, then enlarged again. Nivolumab was therefore administered and the liver metastases showed a significant reduction in size. The interval between doses gradually increased due to persistent general fatigue. At 28 months after starting nivolumab therapy, bronchitis and adrenal insufficiency appeared, so treatment was discontinued. As of 3.5 years after cessation of nivolumab immunotherapy, tumor regression continued to be maintained. The patient remains alive as of 8 years after recurrence of liver metastases.

Conclusion: We encountered a case in which the patient received nivolumab therapy for recurrent liver metastases from gastric cancer and survived long term after discontinuing treatment.