Liquid Biopsy in Lung Cancer: Nano–Flow Cytometry Detection of Non–Small Cell Lung Cancer in Blood

Non–small cell lung cancer (NSCLC) remains a leading cause of global mortality, with current screening and diagnostic methods often lacking in sensitivity and specificity. In our endeavor to develop precise, objective, and easily accessible diagnostic biomarkers for NSCLC, this study aimed to leverage rapidly evolving liquid biopsy techniques in the field of pathology to differentiate NSCLC patients from healthy controls by isolating peripheral blood samples and enriching extracellular vesicles (EVs) containing lung-derived proteins (thyroid transcription factor-1 [TTF-1] and surfactant protein B [SFTPB]), along with the cancer-associated protein CD151⁺ EVs. Additionally, for practical applications, we established a nano–flow cytometry assay to detect plasma EVs readily. NSCLC patients demonstrated significantly reduced counts of TTF-1⁺ EVs and CD151⁺ EVs in plasma compared with healthy controls (P < .0001), whereas SFTPB⁺ EVs showed no significant difference (P > .05). Integrated analysis of TTF-1⁺, CD151⁺, and SFTPB⁺ EVs yielded an area under the curve values of 0.913 and 0.854 in the discovery and validation cohorts, respectively. Thus, although further validation is essential, the newly developed technologies are of great significance for the robust detection of NSCLC biomarkers.