Immunohistochemical Evaluation of Urokinase Plasminogen Activator Receptor in Noninvasive and Early Invasive Urothelial Papillary Neoplasia

Objective: To investigate urokinase plasminogen activator receptor (uPAR) expression in urothelial papilloma and in noninvasive and early invasive papillary carcinoma.

Study Design: The study included 40 cases of papillary neoplasia of the urinary bladder subdivided into 10 cases of urothelial papilloma (UP); 10 of papillary carcinoma, grade 1; 10, grade 2 (G2); and 10, grade 3 (G3). Invasion of the subepithelial connective tissue was present in 5 cases of G2 and 7 cases of G3. According to the 2002 revision of the TNM system, these cases were defined as T1 and the others as Ta. uPAR expression was evaluated with an immunohistochemical technique in 5-microns-thick tissue sections.

Results: Difference in the distribution of positive cases in the 4 groups were statistically significant and greatest in G3. Statistically significant differences were also observed between Ta and T1 cases in terms of uPAR intensity.

Conclusion: Detection of immunoreactivity for uPAR was associated with high grade UP carcinomas. These data indicate that uPAR is potentially an important prognostic factor in bladder carcinoma.