The emerging role of TROP2 as a diagnostic and prognostic biomarker in bladder tumor.

Bladder cancer, predominantly urothelial carcinoma (UC), remains a significant global health challenge due to high recurrence rates and treatment resistance. While standard diagnostic methods such as urinary cytology and cystoscopy are widely used, they have limited sensitivity and specificity. Recently, Trophoblast Cell Surface Antigen 2 (TROP2) has emerged as a promising biomarker and therapeutic target in UC. Highly expressed in urothelial tumors but minimally present in normal tissues, TROP2 plays a crucial role in tumor proliferation, adhesion, and invasion. Immunohistochemical and molecular studies have demonstrated its potential diagnostic and prognostic value, while its therapeutic targeting through antibody-drug conjugates like Sacituzumab govitecan has shown clinical effectiveness, particularly in metastatic UC. However, heterogeneity in TROP2 expression, potential resistance mechanisms, and the significance of cytoplasmic vs. membranous localization remain areas of ongoing investigation. This review explores TROP2’s molecular characteristics, its role as a diagnostic and prognostic marker, and its implications as a therapeutic target in UC. By consolidating current evidence, we aim to provide insights into TROP2’s clinical relevance as a diagnostic and prognostic biomarker and its potential in personalized bladder cancer management.