SHR-1701 Combined With Chemotherapy for Gastric or Gastroesophageal Junction Adenocarcinoma With Peritoneal Metastasis

Inclusion criteria

• Age ≥ 18 years old.
• Pathologically confirmed gastric or gastroesophageal junction adenocarcinoma (Siewert typeⅡ and type Ⅲ gastroesophageal junction adenocarcinoma are eligible for inclusion).
• Definitively diagnosed with peritoneal metastasis by exploratory laparoscopy and/peritoneal lavage cytology (CY0P1/CY1P0/CY1P1 are eligible, ovarian metastasis is permitted), and without gastric outlet obstruction or intestinal obstruction.
• No prior anti-tumor treatment history (including radiotherapy, chemotherapy, targeted therapy, immunotherapy, etc.).
• Eastern Cooperative Oncology Group (ECOG) performance status score of 0-1.
• Normal function of major organs.

Exclusion criteria

• Known HER2-positive.
• Previous history of gastric cancer surgery.
• Contraindications to surgical treatment or chemotherapy, or poor physical status and organ function precluding major abdominal surgery.
• Presence of distant metastases other than peritoneal metastases (e.g., liver, lung, ovarian, para-aortic lymph node, brain metastases, etc.).
• Active autoimmune disease within 4 weeks prior to enrollment or a history of autoimmune disease.
• Significant cardiovascular disease within 6 months prior to enrollment, including unstable angina or myocardial infarction.