Coexisting opportunities and challenges: In which scenarios can minimal/measurable residual disease play a role in advanced non-small cell lung cancer?

Curative therapy was not previously available for patients with advanced non-small cell lung cancer (NSCLC); thus, the concept of minimal/measurable (or molecular) residual disease (MRD) was not applicable to these patients. However, advances in targeted and immunotherapy have revolutionized the treatment landscape for patients with advanced NSCLC, with emerging evidence of long-term survival and even the hope of complete remission (CR) by imaging examination. The latest research shows that patients with oligometastatic lung cancer can benefit from local treatment. After removing the lesions, the choice of follow-up therapy and monitoring of the lesions could remain uncertain. MRD plays a role in identifying early-stage NSCLC patients with high risks of recurrence and determining adjuvant therapy after radical treatment. In recent years, evidence has been accumulating regarding the use of circulating cell-free tumor DNA (ctDNA) to assess MRD in solid tumors. This study discussed the possible applications of ctDNA-based MRD monitoring in advanced NSCLC and described the current challenges and unresolved problems in the application of MRD in advanced NSCLC.