A 73-year-old woman visited our hospital due to carcinoembryonic antigen (CEA) level elevation (110ng/ml). She underwent an upper gastrointestinal endoscopy (EGD), enhanced computed tomography (CT), and positron emission tomography (PET) -CT. She was diagnosed with type 3 esophagogastric junction cancer with paraaortic lymph node (LN) metastases at stage IVA (cT3N4M0). She underwent triplet combination chemotherapy with itraconazole (ITCZ):nab-paclitaxel, oxaliplatin, and S-1 with ITCZ. After six cycles of this regimen, the CEA level was within normal range, and EGD and PET-CT showed no evidence of malignancy. She underwent laparoscopic proximal gastrectomy and lower esophagectomy. The surgical specimen revealed no residual tumor (pathological complete response). Three months later, her CEA level increased to 60.5ng/ml, and she had longitudinal LN recurrence. However, she took S-1 orally for 11 cycles, and the recurrent metastatic LNs improved. She received chemotherapy, including nivolumab followed by ramucirumab and nab-paclitaxel with ITCZ. The CEA level returned to the normal range, and PET-CT showed no evidence of malignancy. Her progression has been stable for 45 months after diagnosis. In summary, we encountered a case of unresectable gastric cancer with conversion surgery after triplet combination chemotherapy with ITCZ.