Heterogeneity of tumor exosomes - role in precision medicine

Cancer liquid biopsies have traditionally involved the use of cell free DNA or circulating tumor cells (CTCs) to characterize the molecular underpinnings of the underlying tumor. Recently extracellular microvesicles known as exosomes have emerged as an important “third rail” of the cancer liquid biopsy, with demonstration of highly preserved cancer-derived DNA and RNA within the exosomal cargo. Paired with ultrasensitive next generation sequencing (NGS) or droplet digital polymerase chain reaction (ddPCR) approaches, profiling exosomal nucleic acids provides an opportunity for early detection, therapeutic stratification and monitoring of cancer patients during therapy. Exosomes have emerged as a key tool in the precision medicine armamentarium, prime for clinical application in cancer diagnosis and therapeutics.