The Feasibility of Dynamic Liquid Biopsy Monitoring During Neoadjuvant Treatment for EGFR-mutated NSCLC

Inclusion Criteria: 1. Patients should voluntarily join this study and sign the informed consent form 2. Patients diagnosed with resectable stage II-IIIB (T1-4N0-2M0, excluding T4 with invasion of vital structures and bulky or infiltrative N2) NSCLC 3. Patients with EGFR 19del or L858R mutations. 4. Age from 18 to 75 years old, both male and female 5. ECOG score 0-1 6. According to the RECIST v1.1 , patients should have at least one measurable lesion 7. For suspicious mediastinal lymph nodes (including pathological enlargement or PET-CT indicating malignancy, etc.), further sampling is required for pathological diagnosis by EUBS, thoracoscopy, or mediastinoscopy 8. According clinical evaluation, the lung function of patients (such as FVC, FEV1, TLC, FRC, DLco, etc.) should be sufficient for pneumonectomy 9. The function of important organs should meet the following requirements: absolute count of neutrophils ≥ 1.5 × 109/L# Platelets ≥ 100 × 109/L# Hemoglobin ≥ 90g/L; Serum albumin ≥ 35g/L; Thyroid hormone (TSH) ≤ 1 × ULN# Serum bilirubin ≤ 1.5 × ULN# ALT and AST ≤ 3 × ULN# International standardized ratio (INR) ≤ 1.5 or prothrombin time (PT) ≤ 1.5 × ULN# Serum creatinine ≤ 1.5 × ULN 10. Female patients at childbearing age are required to use contraceptive measures; for male patients whose partners are women at childbearing age, effective methods of contraception should be used during the trial period Exclusion Criteria: 1. Patients with other primary malignancies within the past 3 years (excluding cured skin basal cell carcinoma and cervical carcinoma in situ) 2. Patients with active hepatitis B/C 3. Patients with any active autoimmune diseases or a history of autoimmune diseases 4. Patients who are using immunosuppressive agents or require systemic hormone therapy 5. Patients with hypertension but without good control even through antihypertensive medication treatment ; patients with clinical symptoms or diseases related to unsatisfying cardiac function 6. Patients with abnormal coagulation function (INR\>2.0, PT\>16s) 7. Arterial/venous thrombotic events occurred before screening within 6 months 8. Patients with active infection 9. Patients with congenital or acquired immune dysfunction (such as HIV infection) 10. According to the judgment of the researchers, patients have other factors that may affect the results of the research or cause the research to be terminated