Extracellular vesicles in gastric cancer: biological functions, clinical applications, and engineering strategies.

Gastric cancer (GC) remains a major malignancy of the digestive system, with a high burden in developing countries where early diagnosis is often limited. As a result, many patients are diagnosed at advanced stages, and despite comprehensive treatment strategies, recurrence rates remain high. These challenges underscore the urgent need for improved diagnostic and therapeutic approaches. Extracellular vesicles (EVs) have attracted increasing attention due to their critical roles in tumor progression and intercellular communication. Emerging evidence suggests that EVs are involved in key processes such as immune modulation, metastasis, and therapeutic resistance, highlighting their potential as biomarkers and therapeutic targets. In this review, we systematically summarize the biological functions of EVs in GC and critically evaluate their translational potential in diagnosis and therapy. We also discuss current challenges, including technical limitations, lack of standardization, and insufficient clinical validation, and propose future directions for advancing EV-based precision medicine.