Cytokeratin 5/6 expression in bladder cancer: Association with clinicopathologic parameters and prognosis

Objectives: Well differentiated keratinized squamous component as a part of urothelial carcinoma can be easily appreciated; however non-keratinizing squamous differentiation closely resembles urothelial differentiation. In addition prognostic significance of CK 5/6 expression in the absence of apparent squamous differentiation is still unclear. Therefore, in the present study we aimed to evaluate the frequency of CK 5/6 expression in 127 cases of urothelial carcinoma and its prognostic significance in loco-regional population. Results: Positive CK5/6 expression was noted in 6.3% (8 cases) and 13.4% (17 cases) revealed focal positive CK 5/6 expression. On the other hand, 80.3% (102 cases) showed negative CK5/6 staining. Significant association of CK5/6 expression was noted with tumor grade and muscularis propria invasion, however no significant association was noted with overall and disease free survival. On the basis of the results of our study we can conclude that CK5/6 is an independent prognostic biomarker in urothelial carcinoma and therefore can be used in the prognostic stratification of the patients with bladder cancer.