Extracellular Vesicles as Diagnostic Biomarkers in Cancer: From Technological Advances to Clinical Translation

Extracellular vesicles (EVs) are emerging as powerful tools for non-invasive cancer diagnostics. Released by virtually all cell types, EVs carry molecular cargo—RNA, DNA, proteins, and lipids—that reflects the physiological and pathological state of their cells of origin. In oncology, tumor-derived EVs are abundant in biofluids and can cross biological barriers, offering stable, information-rich biomarkers for early detection, molecular profiling, and longitudinal disease monitoring. This review outlines the unique advantages of EVs compared to more established liquid biopsy analytes, such as circulating tumor cells or cell-free DNA, and examines how EVs can provide complementary or even superior diagnostic insights. We highlight recent technological innovations enabling more sensitive and specific EV analysis including microfluidic devices and single – vesicle imaging system. Recent advancements in microfluidic EV devices enable the high-throughput purification and on-chip analysis of EVs. When merged with single-vesicle imaging systems, they provide nanoscale characterization of EVs, addressing long-standing challenges such as EV population heterogeneity and the detection of rare tumor-specific signals. In addition, we discuss key efforts to standardize EV-based assays, including the MISEV guidelines and EV-TRACK, and analyze regulatory and practical considerations that currently limit clinical adoption. While EV diagnostics are not yet routine, continued advances in methodology, standardization, and validation are rapidly paving the way for broader clinical integration in precision oncology.