Irinotecan Liposome II + 5-FU/LV + Oxaliplatin + Karelizumab in Neoadjuvant Treatment of Gastric Cancer

FOLFIRINOX + Karelizumab Irinotecan liposomal: 60 mg/m2, IV infusion, d1; 5-FU: 400 mg/m2, IV infusion, d1, followed by 1200 mg/m2/d x 2 days of continuous IV infusion (total 2400 mg/m2, 46-48h infusion); Calcium folinate: 400 mg/m2, IV infusion, d1; Oxaliplatin: 85 mg/m2, IV infusion, d1; Karelizumab: 200 mg, IV infusion, d1; Repeat every 2 weeks.