This study estimated the expression of CK-7, CK14, and CK-20 protein in human bladder carcinoma, urothelial carcinoma (UC) in comparison to squamous cell carcinoma (SCC) and to show its possible correlation to clinicopathologic parameters (grade and stage and bilharziasis), and investigate whether cytokeratin 14 immunostaining may be useful to detect early
squamous metaplasia in bladder biopsies and in association with UC. We evaluated the bladder tissues of 200 patients with bladder carcinoma, 150 patients had UC, and 50 patients had SCC. Imunohistochemical technique was used for detection of CK7, CK14 and CK20 monoclonal antibodies. The mean age of the patients was 55 years (range51- 70 years). The UC were classified according to grades into grade I, II and III in 20, 40 and 90 cases, respectively. Stages of UC were: Ta in 10, T1 in 60 and 90 patients with muscle-invasive T2-3. In UC cases 105 /150 (70%) were positive for over expression of CK20. In the same group of UC 120/150 (80) were positive for over expression of CK7. Negative expression was found in SCC cases. A High grades of the UC were associated with decrease expression of CK 20, there were 20 (100%) in GI, 35 (87.5%) in GII, 50 (68.6%) in GIII (P <0.01), and an increase expression of CK7 4 (20%) in GI, 26 (65%) in GII, 90(100%) in GIII (P <0.01). CK20 expression decreased as the tumor stages increased, it was 15 (100%) in Ta, 50 (83.3%) in T1, 40 (50%) in T2-3 (P <0.01), while CK7 showed increase expression in 2 cases with Ta tumor
(20%), 38 (47.5%) in T1, 80 (100%) in T2-T3 (P <0.01). The present study confirmed that CK14 is expressed in SCC and in UC with squamous differentiation.