Tyrosine Kinase Inhibitors

This is an observational study, aiming to investigate whether the ctDNA dynamics analyzed by the K-TrackTM assay could predict early response to Tyrosine kinase inhibitors (TKIs) in patients with advanced non-small cell lung cancer (NSCLC). 1. Determine relationship between ctDNA dynamics and clinical response to TKI, * No response/progressive disease = ctDNA levels increase from baseline * Partial response/stable disease = ctDNA levels decrease from baseline * Complete response = ctDNA clearance. 2. Compare and combine ctDNA dynamics and RECIST1.1 to predict clinical response. 3. Determine relationship between ctDNA dynamics and progression free survival, overall survival.