Prospective study of urothelial carcinoma diagnostic performance of two-gene methylation analysis in small-volume urine sample

Early detection of urothelial carcinoma (UC) is challenging because of the limitations of current diagnostic methods. A prospective study at Sun Yat-sen University Cancer Center (Guangzhou, China) evaluated a novel, urine-based H4C6/TWIST1 methylation assay for UC diagnosis. A total of 743 urine samples (387 UC patients; 356 controls) were analyzed. DNA was extracted from 3.5 ml of morning urine, and H4C6/TWIST1 methylation status was assessed with quantitatve PCR. Histopathology served as the reference standard. The assay demonstrated high diagnostic accuracy, with sensitivity 93.0% (95% CI 90.0-93.4) and specificity 92.1% (88.8-94.7). The positive and negative predictive values were 92.8% and 92.4%, respectively. Performance was particularly strong for high-grade tumors and muscle-invasive tumors. Diagnostic efficacy was consistent across age, sex, and tumor location, covering both lower and upper urinary tract carcinomas. The authors conclude that H4C6/TWIST1 methylation detection is a noninvasive, highly accurate, and consistent tool for the initial diagnosis and monitoring of urothelial carcinoma across all grades and stages.