This study will evaluate the pathologic complete response rate of a perioperative chemotherapy combined with tislelizumab and Trastuzumab in patients with resectable gastric cancer. Prior to surgery to resect the tumor, tislelizumab (intravenously, 200 mg on day 1 of every cycle) and trastuzumab (intravenously, 8 mg/kg loading dose, then 6 mg/kg on days 1 of every cycle) will be administered for four cycles and the perioperative chemotherapy contains docetaxel (intravenously, 50 mg/m2 on day 1 of every cycle) and S1 (orally, 400mg/m2 BID on day 1~14 of every cycle) and Oxaliplatin(intravenously, 100 mg /m2 on day 1 of every cycle) will be administered for three cycles prior to surgery.If complete resection, R0 or microscopic residual tumor R1 is achieved, patients will continue with three cycles of SOX and tislelizumab and trastuzumab and then for completion of 12 months treatment with tislelizumab and trastuzumab alone.
Perioperative chemotherapy improves overall survival (OS) and disease-free survival (DFS) compared with surgery alone in patients with resectable gastric adenocarcinoma (GA) or gastro-oesophageal junction adenocarcinoma (GEJA). The addition of tislelizumab and trastuzumab to chemotherapy improves outcomes in patients with HER2-positive advanced gastric cancer (GC), and the investigators aimed to explore its role in the perioperative setting.