Dr. Lopategui on the Use of Liquid Biopsies in Lung Cancer

Jean Lopategui, MD, associate professor of pathology and director of Translational Genomics and of the Molecular Genetics Pathology Fellowship at Cedars-Sinai, discusses the use of liquid biopsies in lung cancer.

Liquid biopsies are still an emerging technology, says Lopategui. While these tests are considered to be a less invasive alternative to tissue biopsies, the 2020 National Comprehensive Cancer Network guidelines state that liquid biopsies should only be used if a patient is medically unfit for an invasive tissue biopsy or if there is inadequate tissue for molecular analysis.

One of the drawbacks of liquid biopsies is the rate of false-negative results, says Lopategui. Plasma-based circulating tumor (ct)DNA and detection requires a very high sensitivity. However, the number of ctDNA copies in patient samples is not always high; this can lead to false negatives. As such, if a liquid biopsy is performed, a follow-up tissue-based analysis should also be done if an oncogenic driver is not identified, concludes Lopategui.