Comprehensive Review of Extracellular Vesicles in Thyroid Cancer: From Methodological Approaches to Biological Functions and Clinical Applications

Thyroid cancer (TC) is one of the most common endocrine malignancies and ranks among the ten most frequently diagnosed cancers worldwide, highlighting the need for improved diagnostic and monitoring strategies. Extracellular vesicles (EVs) are nano-sized, membrane-enclosed particles released by nearly all cell types that carry selectively sorted bioactive cargo capable of influencing the behavior and fate of recipient cells. Although their molecular composition is shaped by their cells of origin, cargo loading is a regulated process that contributes to EV-mediated intercellular communication and cell-specific targeting. In TC, EVs have emerged as important mediators of tumor progression and microenvironment modulation. Recent advances underscore the diagnostic and prognostic value of EVs as non-invasive biomarkers, particularly through the detection of EV-associated non-coding RNAs, proteins, lipids, and other molecular signatures. However, methodological variability and limited clinical validation remain key barriers to clinical translation. Further preclinical and clinical studies are needed to establish the role of EVs in liquid biopsy and personalized targeted therapy for TC. This review provides a comprehensive and systematic overview of EVs in TC, with particular emphasis on methodological factors influencing EV research, including sample-specific isolation and characterization strategies. Based on a systematic literature survey, this review integrates current knowledge on EV-associated cargo, biological functions, biomarker and therapeutic potential while critically evaluating methodological challenges and outlining future directions for clinical translation.