Endoscopic Cryoablation Combined With PD-1 in Advanced Gastric Cancer

Inclusion Criteria:

1. Patients diagnosed with advanced gastric cancer (stage IV in AJCC 8th edition staging, including locally progressive gastric cancer with unresectable factors (IVa) and gastric cancer with distant metastases (IVb); Bowman's staging type I, II, and III), who are unable to be surgically resected or do not tolerate surgical resection, and who have undergone progression after 1-2 lines of conventional chemotherapy;
2. Age greater than 18 years and less than 80 years;
3. WHO pathology type: adenocarcinoma, neuroendocrine tumor;
4. Expected survival greater than 3 months and controllable distant metastases as judged by the physician;
5. Important organ functions must be met: ① Liver function: ALT and AST ≤ 2.5 times the positive range, total bilirubin ≤ 2.0mg/dL; ② Renal function: creatinine clearance ≥ 40mL/min calculated using the EPI formula;
6. Blood routine: Hgb≥70g/L,ANC≥1.5×109/L,PLT≥80×109/L;
7. Coagulation function: PT and APPT \<2 times the normal value;
8. Pregnancy test must be negative in women of childbearing age;
9. ECOG score ≤2;
10. Signed informed consent.

Exclusion Criteria:

1. Pregnant or breastfeeding women, or women with pregnancy plans within six months;
2. Infectious diseases (e.g. AIDS, syphilis, active tuberculosis);
3. Patients with active hepatitis B or C infection;
4. Combination of other primary malignant tumors;
5. Patients who have participated in a clinical trial within one month;
6. Patients taking antiplatelet or anticoagulant drugs within the last week;
7. Patients with gastric cancer combined with active bleeding;
8. Large amount of ascites (ascites ≥3000ml);
9. Cardia obstruction or pyloric obstruction;
10. patients with combined active infection or autoimmune disease;
11. Those who the doctor thinks there are other reasons not to be included in the treatment.