Key Points
• The current literature review covers NSCLC liquid biopsy and the advantages/disadvantages of different approaches.
• The authors noted that liquid biopsy is uncommonly used, although its popularity is increasing. Of note, costs and sensitivity vary by technique. “By using liquid biopsy more widely in selected patients, complication rates can be reduced, and constant disease monitoring is made considerably easier,” they wrote.
• The authors stressed that liquid biopsy can be used for the assessment of mutation status—especially EGFR mutations. It can also be used to screen treatment response or the development of resistance.
• “The sensitivity of testing for EGFR mutations via ctDNA testing is dependent upon the total amount of ctDNA in the bloodstream, which can vary between patients, but also in one and the same patient at different timepoints,” they wrote. “The half-life of ctDNA has been shown to be <2 hours (62). Tumor burden also strongly determines ctDNA concentration, and patients with more extensive disease tend to harbor higher levels of ctDNA.”