While researchers and clinicians are largely enthusiastic about using liquid biopsies to detect and monitor cancer, they aren't quite ready yet to replace conventional biopsies, Nature News reports.
It recounts the story of an 80-year-old woman with lung cancer who underwent a lung biopsy and targeted treatment, and though her cancer retreated, it then came back. Rather than do another painful lung biopsy, her oncologist, Geoffrey Oxnard, who is at the Dana-Farber Cancer Institute, instead turned to a liquid biopsy. From a sample of the patient's blood, Oxnard determined that her tumor had mutated to become resistant to her current treatment. But, a drug against that mutation was under study, and he got her enrolled in the trial.
However, Nature News notes that the patient, in order to be enrolled, had to undergo a conventional biopsy to confirm the liquid biopsy findings to enroll in the trial, as there are questions reading the approach's accuracy and sensitivity.
Next-generation sequencing approaches and digital PCR are helping researchers and clinicians wring the most out of liquid biopsies as they enable tumor and normal DNA to be told apart and detect low amounts of DNA from blood, respectively.
At the same time, there are three different liquid biopsy approaches. It can examine cell-free DNA, tumor cells that have broken free, or exosomes shed by cells. As Nature News writes, each of these approaches offer slightly different views into disease, but they still need to be refined. "They have a powerful role in helping patients get to the right treatment," Oxnard adds.