Abstract
Gastrointestinal (GI) cancers represent a heterogeneous group of malignant neoplasms arising from the digestive tract, including gastric, colorectal, hepatic, pancreatic, and biliary cancers. These tumors represent a major public health challenge due to their aggressive nature and poor prognosis. Although significant progress has been made in diagnostic imaging, endoscopy, and multimodal therapies, early detection remains difficult. Conventional serum biomarkers often lack sufficient sensitivity and specificity for reliable diagnosis, prompting a growing interest in identifying novel, minimally invasive biomarkers. In this context, liquid biopsy is emerging as a revolutionary tool in oncology. Among its components, extracellular vesicles (EVs) have gained increasing attention because they carry a wide range of molecular cargoes that reflect the biological state of their tumor of origin. In particular, EV-associated microRNAs (miRNAs) hold great promise as biomarkers for early cancer detection, real-time monitoring of disease progression, and assessment of therapeutic response. This review discusses the diagnostic and prognostic potential of EVs as novel biomarkers in GI cancers, emphasizing EV-contained miRNAs as a key resource for the development of personalized and precision medicine strategies.