Detection of Minimal Residual Disease Using Exosomal miRNA Distant Metastasis Markers

Postoperative recurrence in gastric cancer is largely driven by occult micrometastatic disease that remains undetectable by conventional imaging. While circulating tumor DNA (ctDNA) assays have shown utility in MRD detection, their limited sensitivity and tumor-type variability hinder consistent application in gastric cancer. Exosomal microRNAs (exo-miRNAs), encapsulated within lipid bilayer vesicles, remain stable in circulation and reflect tumor-derived molecular information. This study seeks to develop and validate an exosomal miRNA-based signature capable of detecting minimal residual disease and predicting future distant metastasis after curative gastrectomy. Study Phases 1. Discovery Phase - Comprehensive small RNA sequencing to identify miRNAs specific to distant metastasis in gastric cancer. 2. Training Phase - RT-qPCR-based quantification of candidate exo-miRNAs in postoperative plasma samples to develop an MRD signature. 3. Validation Phase - Independent cohort testing to evaluate the diagnostic performance, sensitivity, and specificity of the exosomal MRD panel. Ultimately, the ENLIGHT assay aims to guide postoperative adjuvant chemotherapy by stratifying patients according to MRD status, enabling precision surveillance and early intervention.