Urinary exosomal FAM153C-RPL19 chimeric RNA as a diagnostic and prognostic biomarker for prostate cancer in Chinese patients.

Prostate cancer (PCa) is one of the most common malignancies in men, with an increasing incidence worldwide. Early detection is crucial for improving patient outcomes, yet the current biomarker, prostate-specific antigen (PSA), lacks sufficient specificity and sensitivity, especially in the diagnostic gray zone (PSA 4-10 ng/mL). Novel noninvasive biomarkers are needed to enhance diagnostic accuracy and reduce unnecessary biopsies. This study analyzed prostate cancer tissue, plasma, and urine samples from multiple cohorts, including the Chinese Prostate Cancer Genome Epigenome Atlas (CPGEA) dataset and external validation cohorts. RNA sequencing and qPCR validation were performed to assess the expression levels of FAM153C-RPL19 in urinary exosomes from PCa patients (n = 826), non-PCa individuals (n = 352), benign prostatic hyperplasia (BPH) patients (n = 396), and healthy controls (n = 428). Receiver operating characteristic (ROC) analysis was conducted to compare the diagnostic performance of FAM153C-RPL19 with PSA and PCA3. FAM153C-RPL19 levels were significantly higher in urinary exosomes of PCa patients than in healthy, BPH, and non-PCa controls. Higher levels correlated with advanced stages (Stage III-IV) and Gleason scores (GS ≥ 7). Urinary exosomal FAM153C-RPL19 outperformed plasma exosomes as a diagnostic marker. It showed superior diagnostic accuracy (AUC = 0.93) over PSA (AUC = 0.81), especially in PSA gray-zone cases (AUC = 0.92). Higher levels were associated with poor prognosis (HR = 2.95, 95 % CI: 1.90-4.58). Combining FAM153C-RPL19 with PSA and PCA3 improved diagnostic performance (AUC = 0.97). These findings suggest that urinary exosomal FAM153C-RPL19 is a promising noninvasive biomarker for prostate cancer detection and risk stratification, with higher specificity and sensitivity than PSA, particularly in the diagnostic gray zone. Its strong correlation with disease progression and prognosis further supports its potential clinical utility in liquid biopsy-based PCa screening.