Exploring the Mechanism of Primary Resistance to Third-generation EGFR-TKIs as First-line Treatment in EGFR-positive Advanced NSCLC (PRECISE Study)

Inclusion Criteria: 1. Age \>18 years; 2. Histological or cytopathological diagnosed NSCLC; 3. According to the American Joint Committee on Cancer (AJCC) eighth edition of the Lung Cancer Staging Manual, the clinical stage is unresectable IIIB-IV or recurrence and metastasis after surgery; 4. At least one measurable lesion can be evaluated according to the Response Evaluation Criteria In Solid Tumours v1.1 (RECIST1.1) criteria; 5. Positive EGFR mutation confirmed by tissue or cytology (pleural fluid, cerebrospinal fluid, etc.); 6. Use of third-generation EGFR-TKIs approved by the NMPA for NSCLC as first-line therapy; 7. Cooperate with the provision of clinicopathological data, imaging data, sample collection, and follow-up required for the research process, and agree to use the test data for subsequent research and product development; 8. Agree to participate in this study and sign an informed consent form. Exclusion Criteria: 1. Patients who cannot understand the content of the experiment and cannot cooperate, and those who refuse to sign the informed consent form; 2. Pregnant and lactating women; 3. Other malignant neoplastic diseases within 3 years; 4. Patients who have undergone other clinical drug trials; 5. Received systemic anti-tumor therapy within 2 years;