Circulating tumor DNA-minimal residual disease: An up-and-coming nova in resectable non-small-cell lung cancer

Circulating tumor DNA (ctDNA) in the bloodstream can be used to reliably identify a minimal residual disease (MRD). ctDNA-MRD has demonstrated clinical values as a predictive and prognostic marker for resectable nonsmall cell lung cancer (NSCLC) regarding efficacy evaluation, recurrence monitoring, risk classification, and adjuvant treatment choices, and it has the advantage of being non-invasive, real-time, and dynamic. A recent large-scale prospective study of patients with resectable NSCLC revealed that patients with longitudinal undetectable MRD might represent a potentially curable population, benefiting many patients by eliminating wasteful therapies and side effects. However, there are still barriers to using ctDNA-MRD in clinical management, and the most significant is the lack of high-sensitivity detection technologies and consistent detection times. Herein, we defined the clinical significance of ctDNA-MRD in resectable NSCLC, summarized the available next-generation sequencing (NGS) detection approaches, and speculated on future clinical trial design and detection technology optimization.