Liquid biopsy in lung cancer.

Precision medicine based on biomarkers, such as genetic abnormalities and PD-L1 expression, has been established for the treatment of nonsmall cell lung cancer. Recently, liquid biopsy has emerged as a valuable and minimally invasive alternative. This method analyzes blood and other bodily fluids to detect cancer-related genetic abnormalities and molecular residual disease (MRD). Liquid biopsy, which includes testing for circulating tumor cells, circulating tumor DNA (ctDNA), and microRNA (miRNA), offers several advantages over conventional methods. It is minimally invasive, can be performed repeatedly, and provides crucial information for early cancer diagnosis, genotyping, and treatment monitoring. Elevated ctDNA levels and miRNA markers show promise for early diagnosis. Liquid biopsy complements traditional tissue biopsy during genotyping, particularly when tumor samples are insufficient. Tests such as Cobas® EGFR Mutation Test v2 and Guardant360® CDx have been shown to be effective in detecting genetic mutations and guiding treatment decisions. Although the accuracy of liquid biopsy is still lower than that of tissue biopsy, its clinical utility continues to improve. For cancer prediction recurrence and treatment monitoring, ctDNA analysis can detect MRD earlier than conventional imaging, offering potential benefits for treatment adjustment and early relapse detection. The continuous development and validation of liquid biopsy methods are essential for improving personalized lung cancer treatment strategies.