“The amount of DNA in the blood might be dependent on the size of the tumor and the stage,” says Fred R. Hirsch, MD, PhD, the executive director of the center for thoracic oncology at the Mount Sinai Tisch Cancer Institute in New York City. “Sometimes there is not enough DNA for reliable examination. Sometimes there’s a discrepancy between the molecular findings in the blood and in the tumor.”
In the future, the role of liquid biopsies in treating lung cancer may expand. “I see a role for liquid biopsy in the treatment decisions for individual patients,” Hirsch says.
“I also see a future role in monitoring treatment effects and an early determination of when a tumor gets resistant to the given molecular therapy or immunotherapy,” he says. “A liquid biopsy may detect increasing abnormal tumor DNA in the bloodstream, indicating tumor progression, for instance, well before it can be seen on a CT scan.”
