The Diagnostic and Prognostic Value of Immunohistochemical Markers in Bladder Cancer: A Real-World Study of 477 Patients.

Introduction: To investigate the diagnostic and prognostic value of commonly used immunohistochemical markers regarding high-grade disease, muscle-invasion bladder cancer (MIBC) and survival in bladder cancer. Methods: A total of 477 patients diagnosed with bladder cancer at Peking University Cancer Hospital between 2009 and 2024 were included. The immunohistochemical markers included CK7, CK20, GATA3, Uroplakin 3, CK5/6, P40, P63, Syn, CD56, CGA, Vimentin, S100, LCA, Ki67, P53, Her2, EGFR, PD-L1, PD-1 tumor, PD-1 stroma, and Pan-TRK. Logistic analyses were used to determine the diagnostic value of the markers for high-grade disease and MIBC. Cox regression analyses were used to determine the prognostic value of the markers for survival. Results: We found Ki67 positivity (p < 0.001) and Her2 positivity (p = 0.001) might have an association with high-grade disease, while no marker demonstrated diagnostic value for MIBC. Patients with CK7 positivity (p = 0.012), Uroplakin 3 positivity (p = 0.004), and PD-1 (stroma) positivity (p = 0.037) had better overall survival (OS) than those with negative expression, while Cox regression analyses showed only CK7 positivity (p = 0.025) and Uroplakin 3 positivity (p = 0.008) had prognostic value for better OS. However, considering there were only 2 CK7-negative patients, the sample size might be insufficient to demonstrate its prognostic value. Conclusions: These results suggest that Ki67 positivity and Her2 positivity might have association with high-grade disease, and Uroplakin 3 positivity might have prognostic value for better OS. However, these conclusions require further clarification through larger-scale studies in the future.