Northfield, Ill. (July 23, 2025)— The expanded use of exosomes in liquid biopsies promises an even more comprehensive, sensitive, and less invasive approach to tumor detection and monitoring, according to a new article published by the CAP.
Recent research shows the full potential of an exosome powered liquid biopsy comes from improved sensitivity when combined with circulating tumor DNA (ctDNA). Combining exosomal ribonucleic acid (RNA) with ctDNA significantly improves mutation detection rates.
“Liquid biopsies have transformed cancer testing by offering a less invasive alternative to tissue biopsies, but even advanced methods like circulating tumor cells and circulating tumor DNA have sensitivity and scope limitations,” said Jordan Seth Laser, MD, FCAP, Chair of the CAP Personalized Health Care Committee. “Exosomes represent the next evolution of liquid biopsy.”
For example, one clinically relevant study demonstrated this enhancement for assessing EGFR activating mutations in lung cancer. This approach led to a nearly 10-fold increase in detectable EGFR mutation copies--a promising development for both advanced and early-stage cancers.
Exosomes are tiny extracellular vesicles that are naturally secreted by living cancer cells into various biofluids including blood, urine, and cerebrospinal fluid. Rich in analytes such as DNA, RNA, proteins, and lipids, exosomes act as molecular messengers and are proving to be an abundant, stable, and highly informative source of cancer biomarkers. Unlike ctDNA, which is derived from dying cells and found in limited quantities, exosomes are released continuously, up to 20,000 per cancer cell every 48 hours, capturing live-cell activity and enhancing diagnostic potential.
“Exosomes allow us to detect a broader range of mutations, splice variants, and fusion genes, often with far greater sensitivity than existing ctDNA-based methods,” explains Dr. Laser.
A major advantage in molecular diagnostics is exosomes’ ability to preserve RNA integrity over time, allowing for simplified handling and processing without degradation. Beyond oncology, exosomes are also being explored for their diagnostic potential in transplant rejection, cardiovascular disease, neurodegenerative disorders, prenatal screening, and immune conditions.
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