Quantitative Detection of CEA mRNA in the Smog and Tissue Exudate Whole Process Collected During Laparoscopic (Robotic) Radical Gastrectomy in Gastric Cancer Patients

Inclusion Criteria: * Gastric adenocarcinoma confirmed by preoperative pathology * Endoscopic and CT/MRI enhanced examination confirmed that cT1-4aN0-3M0 has the possibility of resection * To undergo radical gastrectomy (laparoscopic or robotic) under general anesthesia+/- epidural anesthesia (carbon dioxide pneumoperitoneum) * Willing and able to comply with the research protocol * Reach a written consent agreement before registration, and fully realize the right to withdraw from the study at any time without any loss Exclusion Criteria: * Urgent surgery is required due to tumor emergencies (such as bleeding, perforation, and obstruction) * Extensive peritoneal metastasis can be seen during intraoperative exploration * Other diseases requiring simultaneous surgery * Patients with ascites * Pregnancy