The Role of Liquid Biopsy in the Diagnostic Testing Algorithm for Advanced Lung Cancer

The discovery of therapeutically targetable oncogenic driver alterations has led to marked improvements in NSCLC outcomes. Targeted agents have been approved for an expanding list of biomarkers. Consequently, the accurate and timely identification of targetable alterations with diagnostic molecular profiling is crucial. The use of multiplexed tissue assays, such as next-generation sequencing (NGS), has increased significantly. However, significant limitations with tissue NGS remain, such as insufficient tissue, scheduling limitations, the need for repeat biopsies, and long turnaround times. Liquid biopsies, using plasma circulating tumor DNA (ctDNA), have the potential to overcome these issues, with simpler sample processing requirements, greater convenience, and better patient acceptability. In particular, an early liquid biopsy may allow patients access to highly effective therapies faster, allow better symptom control and quality of life, prevent rapid clinical deterioration, and reduce patient anxiety at diagnosis. More broadly, it may also allow for the more cost-effective delivery of healthcare to patients.