Identification of faecal extracellular vesicles as novel biomarkers for the non-invasive diagnosis and prognosis of colorectal cancer.

Colorectal cancer (CRC) is one of the most common malignancies that is usually detected late in the clinic. The currently available diagnostic tools for CRC are either invasive or insensitive to early lesions due to the dearth of reliable biomarkers. In this study, we discovered that the extracellular vesicles (EVs) in the faeces of CRC patients can act as a potent biomarker for the non-invasive diagnosis and prognosis of CRC. This finding is based on the identification of two transmembrane proteins-CD147 and A33-on faeces-derived EVs (fEVs) that are intrinsically associated with CRC. The detection results show that the levels of CD147 and A33 on fEVs were upregulated in the CRC patients (n = 48), dramatically distinguishing them from the healthy donors (n = 16). The CD147/A33-enriched EVs offer a clinical sensitivity of 89%, much higher than that (40%) of carcinoembryonic antigen (CEA), a clinically-established serum biomarker for CRC diagnosis. In addition, the analysis of longitudinal faeces samples (n = 29) demonstrated that the CD147/A33-enriched fEVs can be utilized to track the prognosis of CRC. Due to the high compliance of faeces-based detection, the CD147/A33-enriched fEVs could serve as new-generation CRC biomarkers for large-scale, non-invasive CRC screening as well as real-time monitoring of patient outcomes during clinical interventions.