Ten-year follow-up after chemotherapy (S1 + cisplatin + trastuzumab) and surgery for human epidermal growth factor receptor 2-positive stage IV esophagogastric junction cancer with pathological complete response: a case report

Abstract

Abstract Background: In recent years, many reports have focused on the usefulness of conversion surgery, in which chemotherapy is given to patients with unresectable advanced gastric cancer (GC) and radical surgery is performed if resection becomes possible. However, no consensus has been reached regarding the usefulness of this strategy. Case presentation: A 74-year-old man was diagnosed with GC after experiencing abdominal pain. Esophagogastroduodenoscopy revealed an elevated lesion with ulceration at the esophagogastric junction (40 mm in size, type 1 gross type), and biopsy revealed well-differentiated adenocarcinoma. Chest and abdominal computed tomography showed wall thickening at the hilum and multiple enlarged lymph nodes in the left supraclavicular fossa and around the aorta from the hilum to the upper abdomen. These findings were consistent with a malignant tumor at the esophagogastric junction, and esophagogastric junction cancer was diagnosed [T3N3M1 (LYM): stage IV]. Chemotherapy was chosen, and seven courses of S1 + cisplatin (SP) + trastuzumab (HCN) were administered. The patient developed neuropathy, and two courses of S1 + HCN were administered. Approximately 10 months after the start of chemotherapy, upper gastrointestinal endoscopy and positron emission tomography/computed tomography showed that the tumor was almost gone; therefore, we decided to perform conversion surgery. The patient underwent open total gastrectomy, D2 lymph node dissection, and Roux-en-Y reconstruction. Scarring at the esophageal junction was evident on palpation of the specimen, but pathologic examination of the specimen and dissected lymph nodes showed no cancer. Postoperatively, the patient underwent 2 cycles of S1 + HCN followed by 48 cycles of HCN until the second postoperative year. No metastasis or recurrence was observed for 9 years after surgery. Conclusions: We have reported a case of stage IV esophagogastric junction cancer with a pathological complete response obtained by SP + HCN therapy. Conversion surgery after chemotherapy resulted in recurrence-free survival. However, further study is needed to elucidate the effect of surgery on top of chemotherapy for stage IV GC as chemotherapy continues to evolve.