Significance of uroplakin III expression in recurrence of solitary muscle non-invasive bladder cancer.

Numerous immunohistochemical biomarkers for patients with urothelial bladder cancer have been identified in order to predict their biological behavior. The aim of this present study was to examine the uroplakin III (UPIII) expression in homogenous group of non-muscle invasive bladder cancer and to correlate its value with clinico-pathological characteristics of patients and moreover with COX-2 expression and tumor infiltrating lymphocytes (TILs). Tumor specimens from 127 patients with non-muscle invasive bladder cancer, divided into two groups: patients who developed recurrent disease during the first five post-operative years (N=78) and patients without recurrent disease during a follow-up of minimum 5 years (N=49), were retrieved for tissue microarrays construction. On paraffin sections, the immunohistochemical analysis of UPIII expression was performed and staining was semiquantitatively evaluated. Expression of UPIII, including luminal, membranous and cytoplasmic one, was found in more than half of the tumors (57%). Specific staining pattern for UPIII was not associated with age and gender of patients, pathological grade, tumor size, disease stage or recurrence of disease. There was no association between UPIII, COX-2 and TILs, except for a negative moderate association between UP and COX-2 in the group of patients without recurrent tumor, and a strong association between UPIII and in the group with tumor recurrence. The present work gives an insight into the very complex mechanisms involved in tumor biology and progression. Moreover, it highlights the importance of further studies that should include multiple molecular markers in models designed to predict the outcome of non-muscle invasive bladder cancer.