Investigation of Ki67 and Phospho-Histone H3 Expressions in Urothelial Carcinoma of the Bladder by Immunohistochemical Method.

Background: In our study, it is aimed to investigate the relationship between Ki67 and phospho-histone H3 (pHH3) expressions in bladder urothelial carcinomas, with clinicopathological parameters and survival, which have prognostic value.

Methods: The study included 44 cases of high-grade urothelial carcinoma (HGUC), 37 cases of low-grade urothelial carcinoma (LGUC), and 11 nontumoral bladder cases. Ki67 and pHH3 were applied to the paraffin blocks of the tissues of 81 urothelial carcinoma and 11 nontumoral bladder cases by immunohistochemical method. Percentages of Ki67 and pHH3 expressions were evaluated by digital imaging analysis method. Expression percentages were compared with various clinicopathological parameters, and the relationship between them was evaluated.

Results: Ki67 was expressed in 28% of urothelial carcinoma cases and 1% of nontumoral cases. pHH3 was expressed in 10.32% of urothelial carcinoma cases and 0.16% of nontumoral cases. In our study, we found significantly higher Ki67 and pHH3 expressions in urothelial carcinoma compared to nontumoral cases. There was a statistically significant relationship (p < 0.05) and a positive correlation between Ki67 expression and lymphovascular invasion, pT stage, and histological grade. A statistically significant relationship (p < 0.05) and a positive correlation were found between pHH3 expression and lymphovascular invasion, pT stage, recurrence, and histological grade. In addition, a statistically significant relationship was found between Ki67 and pHH3 expressions. In our study, survival was found to be low in high-grade urothelial carcinoma cases with lymphovascular invasion, advanced age (65 years and older), and high Ki67 and pHH3 expression rates.

Conclusions: According to our findings, high Ki67 and pHH3 expressions were found to be associated with poor prognostic parameters such as advanced pathologic stage, high histologic grade, and low survival. Our findings suggest that Ki67 and pHH3 may play a role in the differentiation, progression, and aggressive behavior of urothelial carcinoma. However, further studies are needed to confirm our findings and determine the role of these markers in urothelial carcinoma.