Timing of Immunotherapy for Non-Small Cell Lung Cancer

Inclusion Criteria: Participants must meet all of the following criteria: 1. Age ≥18 and ≤75 years at the time of enrollment. 2. Histologically or cytologically confirmed diagnosis of resectable stage II to III non-small cell lung cancer (NSCLC). 3. Deemed suitable for neoadjuvant immunotherapy combined with platinum-based chemotherapy and subsequent surgical resection based on multidisciplinary team (MDT) assessment. 4. ECOG Performance Status of 0 or 1. 5. No prior systemic antitumor therapy for the current NSCLC diagnosis. 6. Adequate bone marrow, hepatic, renal, and cardiac function based on local laboratory standards. 7. Willing and able to comply with scheduled visits, treatment plans, and other study procedures. 8. Signed informed consent prior to participation. Exclusion Criteria: Participants meeting any of the following criteria will be excluded: 1. Presence of EGFR-sensitive mutations (e.g., exon 19del, L858R) or ALK/ROS1 rearrangements. 2. Presence of uncontrolled or symptomatic brain metastases. 3. History of any other malignancy within 3 years prior to enrollment, except for adequately treated basal cell carcinoma, squamous cell skin cancer, or cervical carcinoma in situ. 4. History of prior systemic therapy (immunotherapy, chemotherapy, or targeted therapy) for lung cancer. 5. Known severe allergic reactions to PD-1 or PD-L1 inhibitors (Grade ≥3 by CTCAE). 6. Active autoimmune disease requiring systemic immunosuppression. 7. Active infections, including active HBV, HCV, or HIV infection. 8. Pregnant or breastfeeding women. 9. Any comorbid condition or uncontrolled illness that, in the opinion of the investigator, may interfere with study participation or pose unacceptable risk.