Early-stage multi-cancer detection through a plasma extracellular vesicle protein signature.

Small extracellular vesicles (sEVs) offer a promising, non-invasive method for cancer detection. Despite global research efforts, successful translation of sEV-based diagnostics remains limited. In this study, we identify a 4-protein sEV biomarker panel (thrombospondin-1, nidogen-1, pentraxin-3, and versican) based on proteomic profiles obtained from an isogenic cancer cell line model. The panel's performance is validated across 22 cancer cell lines and 764 retrospective plasma/serum samples spanning multiple cancer types, yielding robust performance (area under the curve [AUC]: 0.91-1.00). To facilitate clinical application, we develop a multiplex sEV device that integrates nanoshearing-based microfluidics and surface-enhanced Raman scattering (SERS) for simultaneous detection of the 4-protein panel. Using this device on a prospective cohort of 68 patients, we accurately differentiate between benign lung changes and early-stage lung cancer. These findings underscore the potential of sEVs as diagnostic markers for cancer screening. Furthermore, the multiplex microfluidic device's scalability, simplicity, and cost-effectiveness indicate feasibility for large-scale population screening.