The Safety and Efficacy of Neoadjuvant Immunochemotherapy Followed by Laparoscopic Gastrectomy for Gastric Cancer

Inclusion Criteria: * Age: 18-85 years of age * Gastric adenocarcinoma was confirmed by pathology# including histology or cytology## * CT/MRI,PET-CT or laparoscopic exploration were used to confirm the diagnosis of gastric cancer staging as cT2-4a and/or N+ and M0 before operation. * measurable lesions at least should be detected by CT/MRI examination in accordance with the RECIST1.1.#CT scan of tumor lesion length≥10mm#CT scan short diameter≥15mm#scan slice thicknes 5mm# * ECOG#Eastern Cooperative Oncology Group#PS#Performance Status#:0-1 scores; * the expected survival time is more than 12 weeks * the main organ function is normal, which should meet the following criteria: (1) blood routine examination standards should be met#no blood transfusion within 14 days# a#HB≥ 100g/L b. WBC≥3×109/L c. ANC≥1.5×109/L d. PLT≥100×109/L #2#biochemical examination shall comply with the following criteria# 1. BIL#1.5 normal upper limit ULN 2. ALT and AST#2.5 ULN,GPT≤1.5×ULN 3. Cr≤1 ULN#CCR#creatinine clearance rate#60ml/min(Cockcroft Gault formula) * women of childbearing age must have a pregnancy test in 7 days before entering the group (in serum), and the results were negative, and willing to use appropriate contraception during the study period and the last 8 weeks after giving drug test; men should have the surgical sterilization, or adopt the appropriate contraceptive methods during the test and the last 8 weeks after giving drug test# * No other clinical studies were conducted before and during the treatment * participants is willing to participate in this study, sign the informed consent, have good compliance, cooperate with follow-up. Exclusion Criteria: * Previous history of chemotherapy, radiotherapy, targeted drug therapy or immunotherapy * Patients with contraindications for surgical treatment and chemotherapy or whose physical condition and organ function do not allow for larger abdominal surgery * patients with metastasis * Having any active autoimmune diseases or a history of autoimmune diseases (such as interstitial pneumonia, uveitis, enteritis, hepatitis, pituitary inflammation, vasculitis, myocarditis, nephritis, hyperthyroidism, hypothyroidism, including but not limited to these diseases or syndromes); Patients with vitiligo or cured childhood asthma/allergies who did not need any intervention in adulthood were excluded; Autoimmune hypothyroidism treated with a stable dose of thyroid replacement hormone; Type 1 diabetes with stable doses of insulin * A history of immunodeficiency, including HIV testing positive, or other acquired or congenital immunodeficiency disorders, or a history of organ transplantation and allogeneic bone marrow transplantation * Accompanied by serious heart, lung, liver, kidney disease; Have nerve, mental disease; Jaundice or obstruction of the digestive tract with severe infection * pregnant or lactating women * The blood pressure of patients with hypertension cannot be reduced to the normal range by the antihypertensive drugs (systolic pressure \>140 mmHg, diastolic pressure \>90 mmHg) * With # magnitude of coronary heart disease, arrhythmia (including QTc protracted between male \> 450 ms, women \> 470 ms) and cardiac insufficiency * Patients have a clear tendency with gastrointestinal bleeding, including the following situation: local active ulcerative lesions, and fecal occult blood (+ +); with melena and hematemesis history in 2 months; and patients with fecal occult blood (+) and unresected gastric primary tumor; patients with the risk of bleeding should take the gastroscopy test, if it is the gastric cancer, and researchers believe that may results in massive digestive tract hemorrhage#coagulation dysfunction (INR(international normalized ratio)\>1.5, APTT(activated partial thromboplastin time)\>1.5 ULN), with bleeding tendency; * Subjects have failed to control good cardiovascular clinical symptoms or disease, including but not limited to: such as: (1) the NYHA class II heart failure (2) above unstable angina pectoris (3) occurred within 1 year (4) have clinical significance of myocardial infarction (mi) room sex or ventricular arrhythmias without clinical intervention on or after clinical intervention is still poorly controlled * History of interstitial lung disease (except radiation pneumonia without hormone therapy), and history of non-infectious pneumonia * Patients are positive of urine protein (urine protein detection 2+ or above, or 24 hours urine protein quantitative \>1.0g); * A person who has previously been allergic to any component of camrilizumab or to any component of the drug under study * The researchers consider those who were not suitable for inclusion.