Comparing the Efficacy and Safety of Different Postoperative Adjuvant Regimens in Patients With Resectable Adenocarcinoma of the Esophagogastric Junction Who Underwent Radical Surgery After Neoadjuvant Chemotherapy Combined With Immunotherapy and Achieved pCR in Postoperative Pathology

Inclusion criteria

• ✓. Age ≥ 18 years old, gender not restricted;
• ✓. Subjects diagnosed with gastric cancer (GC) or gastroesophageal junction cancer (GEJC) through imaging and other examinations, and with histopathological diagnosis of adenocarcinoma;
• ✓. HER2 overexpression or amplification results are negative;
• ✓. Subjects who have received neoadjuvant chemotherapy for GC/GEJC before, and have undergone at least 3-4 cycles;
• ✓. Having undergone radical surgical treatment and with postoperative pathological result reaching pCR
• ✓. After radical surgery treatment, the investigator assesses that further adjuvant treatment is necessary, and the adjuvant treatment plan must be the one specified in this protocol.