A Case of HER2-positive Advanced Gastric Cancer Treated with Trastuzumab Combination Chemotherapy Followed by Conversion Surgery

Abstract

A 68-year-old man came to our hospital with a chief complaint of epigastric pain. Upper gastrointestinal endoscopy revealed a type 3 tumor in the gastric fundus. Contrast-enhanced computed tomography (CT) of the abdomen revealed numerous enlarged lymph nodes in the para-aortic lymph nodes in addition to the gastric regional lymph nodes. After 7 courses of chemotherapy, PET-CT showed FDG accumulation only in the lower gastric body region and no accumulation in the regional or para-aortic lymph nodes. Conversion Surgery was considered feasible, and open distal gastrectomy was performed after 9 courses. Histopathological examination revealed ypT2, ypN0 (0/12), Ly0, V0, and ypStage IB. The patient did not receive any postoperative adjuvant chemotherapy and has been recurrence-free for nine months. The median survival time for unresectable advanced gastric cancer is about 15 months, which is a poor prognosis, but several cases of long-term survival after R0 resection by conversion Surgery have been reported. We report a case of unresectable advanced gastric cancer who achieved R0 resection by conversion Surgery after successful systemic chemotherapy, including a review of the literature.