[A Case of Pathological Complete Response after Conversion Surgery for HER2-Positive Advanced Gastric Cancer with Multiple Distant Metastases].

The patient is a 70's man. Esophagogastroduodenoscopy and contrast-enhanced CT scan of the abdomen revealed gastric cancer, 2 liver metastases, and peritoneal dissemination. He was diagnosed with unresectable advanced gastric cancer and received 5 courses of chemotherapy(CapeOX plus T-mab). The primary tumor size had reduced, and liver metastases and peritoneal dissemination were not detectable, so laparoscopic distal gastrectomy and partial hepatectomy were performed. Histopathological findings revealed no viable cancer cells in either the primary tumor or the hepatic resection site, and the histological response was Grade 3. The patient has been recurrence-free for 6 months since the surgery. Even in Stage Ⅳ gastric cancer with multiple distant metastases, long-term survival may be expected by conversion surgery after response to chemotherapy.