‘Blood First’ Biopsies Promise Faster, Better Treatment For Lung Cancer Patients
Traditionally, doctors have used tissue samples to conduct biopsies for cancer testing. But the results of a new clinical trial suggest a “liquid biopsy” that evaluates a patient’s blood may offer a faster diagnosis that is just as reliable. This could ultimately allow non-small cell lung cancer patients to receive drugs specifically calibrated to treat their tumors.
Guardant Health believes the results of the 282-patient clinical trial mean their “liquid biopsy” test, Guardant360, is primed to change the medical industry. The study, which will be officially presented at this year’s meeting of the American Association for Cancer Research, may confirm that Guardant’s “blood first” approach is actually more effective at detecting genetic alterations (EGFR, ALK, ROS1, BRAF, RET, MET, and ERBB2) that require targeted medicine. With a better accuracy rate, 27.3 percent compared to 21.3 percent seen in the traditional biopsy method, and a turnaround time of only 9 days instead of 15, Guardant believes their test allows patients to start receiving treatment faster and allows drug makers like Roche, Eli Lilly, and Bayer to develop “gene-targeted” cancer medication.
Another advantage of “blood first” cancer testing is that collecting tissue samples for a traditional biopsy is difficult. Sometimes there simply isn’t enough material for a conclusive test. However, Dr. Alice Shaw, director of the Center for Thoracic Cancers at Massachusetts General Hospital, says even a “liquid biopsy” can miss genetic alterations in some patients. For example, the Guardant test missed ROS1 gene variations about half the time.
Despite this criticism, the new study’s lead author, Dr. Vassiliki Papadimitrakopoulou, a professor at The University of Texas MD Anderson Cancer Center, says the results are still a potential game-changer. “We think the practical implication that this provides about use is to make the liquid biopsy test potentially the first test for patients with non-small cell lung cancer.”
With a market capitalization of $4.7 billion, Guardant is certainly hoping the results of the new clinical trial buoy the demand for “liquid biopsies.” While the specific genes that were tested are rare, combined they account for a third of cancer patients with non-small cell lung cancer, many of whom need more advanced drugs than the standard immunotherapy medications, which don’t always shrink tumors. If Guardant’s wager bears out and “blood first” cancer tests become the norm, lung cancer patients may receive faster and more effective treatment. Increased testing will also grow the burgeoning industry of gene-targeted cancer meds.