The study aims to explore the prevalence of EGFR mutations assessed with ctDNA samples in advanced NSCLC, who had received ≤ 1 prior systemic chemotherapy regimens.

Inclusion Criteria:

• Histologically confirmed stage IIIB/IV NSCLC;
• Patient had received ≤ 1 prior systemic chemotherapy regimens;
• Provision of blood (plasma) sample for ctDNA testing;
• Patient must be able to comply with the protocol;

Exclusion Criteria:

• Prior received ≥2 systemic chemotherapy regimens;
• As judged by the investigator, any evidence of severe or uncontrolled systemic disease (e.g. unstable or uncompensated respiratory, cardiac, hepatic or renal disease);
• Histologically confirmed small cell lung cancer or other metastatic tumors;
• Patient with no histologic or cytological diagnosis;

Patients with Non-small cell lung cancer (NSCLC)