Comparison of Perioperative Immunotherapy, Adjuvant Immunotherapy or Neoadjuvant Immunotherapy for Resectable Stage II-IIIA NSCLC

Inclusion Criteria: 1. Aged 18-75, of either gender; 2. Subjects with resectable stage II-IIIA non-small cell lung cancer (according to the AJCC 8th edition), without EGFR/ALK sensitive mutations, confirmed by histology or pathology; 3. ECOG PS score of 0-1; 4. There are measurable lesions according to RECIST 1.1; 5. Expected survival duration ≥ 3 months; 6. Main organ functions are normal (14 days before enrollment) 7. According to the surgeon's assessment, the total lung function is capable of withstanding the proposed lung resection surgery; Exclusion Criteria: 1. Individuals known to be allergic to recombinant humanized anti-PD-1 monoclonal antibody drugs and their components; 2. Currently participating in and receiving other research treatments; 3. Previously received systemic treatment for resectable stage II-III non-small cell lung cancer, including systemic chemotherapy, targeted therapy, immunotherapy, etc; 4. Patients with active tuberculosis (TB) who are currently undergoing anti-tuberculosis treatment or have received such treatment within the previous 1 year prior to screening; 5. Uncontrollable or symptomatic hypercalcemia (\>1.5 mmol/L calcium ion or calcium \>12 mg/dL or corrected serum calcium \>ULN); 6. Clinically, there is uncontrolled active infection, including but not limited to acute pneumonia; 7. Uncontrollable severe epileptic seizures or superior vena cava syndrome; 8. Previously or currently suffering from other malignant tumors (excluding non-melanoma basal cell carcinoma or squamous cell carcinoma of the skin, breast/cervical carcinoma in situ, superficial bladder cancer, and other carcinoma in situ that have undergone radical treatment with no evidence of disease recurrence); 9. Patients with interstitial pneumonia, history of idiopathic pulmonary fibrosis, organizing pneumonia (such as bronchiolitis obliterans), drug-induced pneumonia, idiopathic pneumonia, evidence of active pneumonia found during chest CT scan screening, or other moderate to severe pulmonary diseases that seriously affect lung function; 10. Known human immunodeficiency virus (HIV) infection (known HIV antibody positive); 11. Having severe cardiovascular diseases, such as New York Heart Association (NYHA) class 2 or above heart failure, unstable angina pectoris, unstable arrhythmia, myocardial infarction or cerebrovascular accident occurring within 6 months before enrollment; 12. Within 2 years prior to the commencement of the study, having received systemic immunosuppressive medications (i.e., using corticosteroids or immunosuppressive drugs) due to any active autoimmune disease; 13. Subjects who received live virus vaccine within 4 weeks before the study began; 14. Patients who have previously received allogeneic stem cell or solid organ transplantation; 15. Pregnant or lactating women, or women who may become pregnant, who test positive for pregnancy before their first medication, or patients who are capable of bearing children but are unwilling to accept contraceptive measures, or whose sexual partners are unwilling to accept contraceptive measures; 16. Researchers believe that factors such as psychiatric or substance abuse history, inability to benefit from the clinical study, or conditions that affect patients' ability to sign informed consent forms (such as drug addiction and substance abuse), or any other clinically significant diseases or conditions that make patients unsuitable for participation in this clinical study (including but not limited to: abnormal laboratory results, clinically active diverticulitis, intra-abdominal abscess, intestinal obstruction, and peritoneal metastatic cancer) can affect study compliance.