Values of circulating tumor DNA for non-small cell lung cancer patients receiving neoadjuvant therapy, progress and challenges: a narrative review

Background and Objective: The value of circulating tumor DNA (ctDNA) in neoadjuvant therapy (NAT) for lung cancer remains controversial. Therefore, we conducted a review to further investigate the role of ctDNA in non-small cell lung cancer (NSCLC) patients undergoing NAT for individualized management. Methods: A search of online databases (PubMed, Embase, Web of Science, Science Direct, and Cochrane Library) was conducted to evaluate the value of ctDNA in predicting relapse, risk stratification, and efficacy of NAT in NSCLC. Only articles published in English within the last 25 years, between January 1st, 1998 and November 30th, 2023, were included. Additionally, the application of ctDNA in NSCLC is briefly reviewed. Key Content and Findings: ctDNA is a non-invasive and dynamic method that plays an important role in future treatment guidance. Additionally, ctDNA successfully predicted the effect of neoadjuvant immunotherapy before surgery, and positive testing was strongly correlated with a lower major pathological response or complete pathological response rate. Sequential testing of ctDNA may serve as a secondary indicator to guide the adjustment of treatment programs. However, the application of this method has been limited by false negative results, a lack of objective indicators, and high costs. These issues must be addressed by researchers. Conclusions: ctDNA has strong potential in NAT, based on positive preliminary studies. However, its widespread use is limited by the high cost of testing. Further research is needed to explore its value in risk stratification and treatment guidance in the future.