Synergistic Effects of PD-1 Antibody and Chemotherapy Followed by Surgery-centric Local Treatment in Patients with Limited-metastatic Gastric Cancer (ROSETTE)

Radical gastrectomy with standard D2 lymphadenectomy will be performed, along with radical surgery for resectable metastatic lesions.

PD-1 monoclonal antibody will be administered at a dosage of 200 mg via intravenous infusion, once every cycle, each cycle spanning three weeks. The specific PD-1 antibody used will be determined by the investigators based on clinical considerations. Potential options include Sintilimab, Toripalimab, Nivolumab, Tislelizumab, or other approved PD-1 antibody products indicated for the treatment of metastatic gastric or gastroesophageal adenocarcinoma.

"Oxaliplatin: 130 mg/m² administered via a 3-hour intravenous infusion on D1 of each 3-week cycle.~Capecitabine: 1000 mg/m² taken orally twice daily. The first dose is administered on the evening of D1, and the last dose on the morning of D15, consisting of 2 weeks of treatment and a 1-week break in each 3-week cycle."

"Additional local treatment for unresected metastatic lesions during phase 2 systemic therapy is permitted, including:~* Bone metastasis, distant lymph nodes, adrenal metastasis: Radiation therapy.~* Lung and liver metastasis: Radiofrequency ablation, interventional embolization, or radiation therapy.~* Peritoneal metastasis: Hyperthermic intraperitoneal chemotherapy (HIPEC).~* Other metastatic lesions: Non-surgical treatment options discussed by the multidisciplinary team."