Abstract 1104: Detection of bladder cancer via urinary DNA mutation and methylation using modified qPCR

Abstract Background: Cystoscopy is the gold standard for diagnosing and monitoring bladder cancer (BC), but it is invasive and painful. Previous studies on urine biopsy have shown that urinary DNA mutation and methylation markers are promising auxiliary diagnostic methods; however, current PCR-based methods for detecting gene mutations or methylations are not accurate enough. This shortcoming highlights the urgent need for a more precise DNA marker detection technology and an auxiliary diagnostic method for bladder cancer. Methods: We developed MTPD-PCR, a highly specific PCR-based detection method that uses dideoxyribonucleic acid (ddNA)-blocking PCR primers and pyrophosphorolysis-activated polymerization to prevent artificially erroneous amplification products that may be introduced by conventional PCR primers, achieving stable detection of mutations with an abundance of 0.01%. We used this method to integrate bladder cancer DNA mutation and methylation biomarkers for non-invasive detection of bladder cancer in urine samples. We conducted a prospective study in a two-center cohort from two tertiary hospitals in China, including 302 patients with histologically confirmed bladder cancer and 200 non-bladder cancer controls. Using cystoscopy combined with histopathological examination as the reference standard, diagnostic accuracy parameters (sensitivity, specificity, and accuracy) were calculated. Results: The study cohort included 302 patients with bladder cancer, of which 114 (37.8%) were low-grade, 175 (58.0%) were high-grade, and 13 (4.2%) were ungraded. Evaluation of 489 analyzable samples showed an overall sensitivity of 85.9%, a specificity of 95.8% (100% in the healthy control group), and a diagnostic accuracy of 89.8%. The positive predictive value and negative predictive value were 97.0% and 81.3%, respectively. For different non-bladder cancer controls, the sensitivity was 85.95%, and the specificity ranged from 90% to 100%. Clinically significant, the method achieved a sensitivity of 70.3% in 91 early-stage tumors and maintained a sensitivity of 81.7% in a validation set of 191 T1/Tis/Ta stage tumors, indicating good performance across different disease stages. Conclusion: This method demonstrated good performance in a cohort of 489 patients, exhibiting high sensitivity and accuracy. This non-invasive molecular detection method can detect bladder cancer at an early stage and serve as a treatment reference, especially suitable for cases with low DNA content, potentially reducing the burden of cystoscopy and avoiding unnecessary secondary transurethral resection of bladder tumors. Citation Format: Di Jin, Roy Tan, Ruiyun Zhang, Haige Chen. Detection of bladder cancer via urinary DNA mutation and methylation using modified qPCR abstract. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 1104.