Evidence suggests that circulating tumor DNA (ctDNA) analysis can noninvasively identify minimal residual disease (MRD) in clinical oncology. The researches will be sharply increased about ctDNA potential clinical application in the near future. In the early stage of NSCLC, ctDNA has been indicated to identify those at high risk of recurrence after radical surgery. And this study will focus on those patients with advanced NSCLC who have long-term benefit from first-line immunotherapy (PFS 12 months). 10ml plasma will be collected every three months until disease progression to interrogate ctDNA by high-depth panel sequencing, exploring its prediction value about the risk of progression. Meanwhile, the investigators would like to explore the lead time of detectable ctDNA before regular imaging finding.
This study aims to explore the correlation of circulating tumor DNA(ctDNA) and the risk of progression in patients with advanced NSCLC who have long-term benefit from first-line immunotherapy (PFS 12 months)