This study will be conducted at Fujian Provincial Cancer Hospital. Its main goals are to evaluate the progression-free survival (PFS) and safety of postoperative immunotherapy combined with radiotherapy in patients with high-risk stage Ⅲ N2 non-small cell lung cancer after surgery. It will also assess the overall survival (OS) of this treatment as a secondary goal.

This study has been approved by the Medical Ethics Committee of Fujian Provincial Cancer Hospital, and the rights and safety of all participants will be fully protected during the trial.

Inclusion Criteria:

• Age: ≥18 years old and ≤75 years old, no gender restriction; Pathologically (histologically or cytologically) confirmed non-small cell lung cancer with multiple N2 metastasis after surgery; No prior radiotherapy, chemotherapy or immunotherapy; At least 3 lymph node metastases confirmed by postoperative pathology; ECOG PS score: 0-2; Expected survival time ≥3 months; Normal major organ function, with basically normal results of blood routine, blood biochemistry and coagulation function tests; Basically normal immune indicators; No severe underlying diseases or severe cardiopulmonary dysfunction.

Exclusion Criteria:

• Known or suspected active autoimmune diseases, or history of autoimmune diseases (e.g., interstitial pneumonia, colitis, hepatitis, hypophysitis, vasculitis, nephritis, hyperthyroidism, hypothyroidism, etc.); History of immunodeficiency (including positive HIV test), other acquired/congenital immunodeficiency diseases, organ transplantation or allogeneic bone marrow transplantation; Interstitial lung disease, drug-induced pneumonia, radiation pneumonia requiring steroid treatment, symptomatic active pneumonia, or severe pulmonary dysfunction; Poorly controlled cardiovascular symptoms or diseases (e.g., NYHA class II or higher heart failure, unstable angina, myocardial infarction within 1 year, uncontrolled arrhythmia); Active hepatitis B (HBV DNA ≥2000 IU/mL or 10⁴ copies/mL) or hepatitis C (positive anti-HCV and HCV-RNA above detection limit); Hereditary bleeding tendency or coagulation dysfunction; bleeding symptoms within 3 months, or positive fecal occult blood (++ or above); Toxicity from prior anti-tumor therapy not recovered to ≤CTCAE grade 1 (except alopecia); Known or suspected allergy to the study drug; Pregnant or lactating women; Subjects deemed unsuitable for inclusion by the investigator.

At the current stage, the IPD sharing plan has not yet been finalized. Following study completion, we will conduct a comprehensive evaluation of data sharing feasibility-including considerations related to participant privacy protection, data standardization, and regulatory compliance-before determining a specific sharing framework based on study progress and relevant requirements.