[A Case of Neuroendocrine Carcinoma of the Stomach Treated with TAS-102].

A 77-year-old-woman underwent distal gastrectomy D2 lymph node dissection and cholecystectomy followed by Roux- en-Y reconstruction for Stage ⅢC gastric neuroendocrine cell carcinoma in January 2017. In July of the same year, an abdominal computed tomography scan revealed liver metastasis in segment 4. For treatment of recurrence, SP therapy(S-1 and cisplatin), ramucirumab plus weekly paclitaxel therapy, and nivolumab were administered in that order. TAS-102 was started as the fourth-line agent for multiple liver metastases, para-aortic lymph node metastases, and cancerous peritonitis. Although Grade 2 anemia, Grade 1 oral mucositis and general fatigue were observed during the treatment, both liver metastases and para-aortic lymph node metastases showed improvement after three courses, and the patient was able to continue 11 courses in 1 year. She died 1 year and 5 months after the first administration of TAS-102. TAS-102 can be effective after immune checkpoint inhibitor as a late treatment for gastric cancer and NEC. The appropriate timing for switching drug therapy may be important in the future. We report a favorable therapeutic effect of TAS-102 after immune checkpoint inhibitor treatment along with a review of the literature.