Researchers from the Abramson Cancer Center found that they could identify significantly more mutations through liquid biopsy instead of a solid tissue biopsy alone—and patients responded favorably to targeted therapies. The findings, published in in JAMA Oncology, show that the addition of liquid biopsy nearly doubled the number of mutations detected compared to what solid tissue testing alone would have found, and 86% of those patients achieved either a complete or partial response.

“Most previous studies have analyzed the impact of liquid biopsy in the setting of a specific clinical trial or for a single therapeutic agent, but our goal here was to quantify the effect of using liquid biopsy in the real-world clinical setting,” says the study’s senior author Erica L. Carpenter, a research assistant professor of medicine and director of the Abramson Cancer Center’s Circulating Tumor Material Center. “To our knowledge, this is the largest study to date aiming to answer this simple, and as of yet, unanswered question as to whether non-invasive biopsies increase the number of potentially effective therapeutic options for our patients. Importantly, we found patients whose therapies were selected based on the liquid biopsy results generally achieved a positive clinical response.”

Biopsies of tumor tissue is sometimes hard to obtain or doesn’t have sufficient DNA for analysis. And mutations may change over the course of treatment, meaning patients are sometimes subjected to multiple invasive biopsies. Instead, liquid biopsies use circulating tumor DNA—shed by tumors and circulating in the blood—to test for mutations using next-generation sequencing. Since tumor DNA can be obtained through a simple blood test in the physician’s office, this ultimately gives patients more therapeutic options and helps them avoid the discomfort and inconvenience of an invasive biopsy procedure.