Dr. Sabari Discusses the Utility of Liquid Biopsies in Lung Cancer

Joshua K. Sabari, MD, assistant professor, Department of Medicine, NYU Langone’s Perlmutter Cancer Center, discusses the utility of liquid biopsies in lung cancer.

Liquid biopsies are critical in patients who have a high likelihood of having a genetic driver alteration, says Sabari. Specifically, younger patients, and patients who are never-smokers; these are patients who should undergo standard immunohistochemistry for EGFR and ALK. In that setting, liquid biopsies are extremely helpful in identifying other alterations such as ROS1 and BRAF. They can also be used to identify other markers, such as RET rearrangements, MET exon 14 skipping alterations, as well as HER2 alterations—both mutations and amplifications, adds Sabari.

However, the cost of these tests is still an issue, as well as the setting in which they are ordered. For example, a physician may want to order a liquid biopsy to monitor disease response or residual disease, but there are no indications for that and no prospective studies showing their benefit. It is, however, indicated upfront, or when an alteration is identified in the face of a potential secondary resistance mechanism, explains Sabari.

For example, if a patient with an EGFR exon 19 activating deletion is started on osimertinib (Tagrisso) and the patient progresses 1 or 2 years later, using a liquid biopsy to identify alterations such as C797S or MET amplification makes sense.