Liquid Biopsy in Lung Cancer for Treatment Monitoring and Disease Tracking

This section explores how liquid biopsy is used beyond diagnosis to monitor treatment response and disease evolution in lung cancer. The experts explain that circulating tumor DNA allows clinicians to observe molecular changes in real time through a simple blood draw. When therapy is effective, ctDNA levels often fall, while rising levels can signal emerging resistance or progression even before changes are seen on imaging.

Dr Husain and Dr Singhal describe how this information is integrated into routine practice. Liquid biopsy is often used when radiographic findings are unclear, when symptoms change unexpectedly, or when clinicians need to understand why a therapy is no longer working. The panel also discusses how they explain this process to patients, emphasizing that liquid testing provides an additional layer of insight rather than replacing scans or tissue biopsies. Many patients appreciate that a minimally invasive test can reveal what is happening inside their cancer at the molecular level.

The discussion also addresses limitations, including the possibility of false negative results when tumors shed little DNA into the bloodstream. In such cases, tissue biopsy or repeat testing may still be needed. Overall, this segment highlights how liquid biopsy has become an important tool for guiding ongoing lung cancer management and enabling more responsive treatment strategies.