Urine is a compound that contains nitrogen-specific elements such as urea, uric acid, and creatinine. Historically, urine has been used to offer medically helpful insights into human health and illness, making it one of the earliest non-invasive diagnostic fluids. With advances in molecular biology, urine-based biomarker identification has shown potential in the detection of various cancers, including bladder, prostate, and hepatocellular carcinoma. Urine cells contain DNA, RNA, circulating tumor DNA (ctDNA), and long non-coding RNA (lncRNA), all of which serve as possible biomarkers. This review focuses on urine biomarkers involved in bladder cancer, including DNA markers, RNA markers, protein markers, and metabolites. Analysis of urine in Non-Muscle Invasive (NMIBC) and Muscle Invasive (MIBC) bladder cancer types offers a promising diagnostic and systematic approach, particularly using Mass Spectrometry (MS) and Nuclear Magnetic Resonance (NMR)-based techniques. Currently, FDA-approved molecular biomarkers such as BTA stat, BTA TRAK, and NMP22 are used to monitor bladder tumors. The Bladder Tumor Antigen (BTA) agglutination test identifies complement factor H-related protein in excreted urine. However, the sensitivity of BTA stat in tumor detection has been reported to vary between 40–70%, while specificities range from 29–96%. Despite these limitations, the discovery of novel potential biomarkers from urine is ongoing, with numerous studies continuing to explore their diagnostic potential. In this review, we aim to identify and evaluate urine-based biomarkers across different cancer types—particularly bladder cancer—through the inclusion of recent research findings. We also seek to gain novel insights to standardize testing procedures and validate these biomarkers in a clinical setting. The implications of this research include easier detection, reduced invasiveness, and improved disease monitoring, ultimately paving the way for more accurate diagnosis, better treatment options, and enhanced patient outcomes in the near future.
Bera et al. (Tue,) studied this question.