Extracellular vesicle-based biomarker in head and neck cancer: prospects and challenges

Abstract

Head and neck squamous cell carcinoma (HNSCC) represents the sixth most common malignancy worldwide. However, very few established diagnostic biomarkers for HNSCC have been universally applied in clinical practice. Recently, much attention has been paid to extracellular vesicles (EVs) regarding their roles as cancer biomarkers because EVs carry plentiful cargoes, including lipids, proteins, nucleic acids, and metabolites. In HNSCC, several molecules carried by EVs, which are derived from peripheral blood and saliva, have been implicated to be effective in cancer detection, staging, treatment planning, response monitoring, and prognosis prediction. Although several EV molecules have been identified to be significantly correlated with a set of clinical-pathological parameters of HNSCC, several key limitations need to be resolved before the clinical application of EVs as carriers of biomarkers in HNSCC. In this review, we discuss current knowledge in the literature regarding EV-based biomarkers in HNSCC, emphasizing current limitations of their clinical applications.