ABSTRACT
Carcinoma of the urinary bladder is one of the most common cancers world wide. It is the fourth most common malignancy in males and the ninth most common malignancy in females. CD44 is a family of cell-surface transmembrane glycoproteins that serve as receptors for hyaluronate and bind extracellular matrix components. CD44 plays a definite role in cell- cell and cell- matrix interactions. Thus, its down-regulation would facilitate loss of cell - cell cohesion, detachment from the basement membrane, and subsequent infiltration of the underlying tissues. It is suggested that the expression of CD44 is associated with differentiation and prognosis in bladder carcinoma. Cytokeratins [CKs] are a family of proteins that form the intermediate filament cytoskeleton of epithelial cells. Cytokeratin 20 [CK20] has been proposed as a marker of neoplastic change as well as a predictor for progression of urothelial carcinoma. The aim of the work is to study the immunohistochemical expression of CD44 and CK20 in carcinoma of the urinary bladder and correlate the immunohistochemical expression of CD44 and CK20 with different prognostic parameters including the grade and stage of the studied tumors. The studied 71 specimen were subjected to the ordinary H and E staining and immunohistochemical staining for CD44 and CK20. Correlative studies between CD44 and CK20 expression with different prognostic parameters including the grade and stage of the studied tumors revealed statistically significant correlation between CD44 and CK20 expression and the tumor grade and stage of urothelial carcinoma cases. No relation was found between the expression of CD44 and CK20 and the presence of Bilharziasis. Loss or reduction of CD44 immunoreactivity and increasing CK20 positiviiy were significantly associated with increasing tumor grade and stage in the studied cases of urothelial carcinoma and to each other, so, they have combined utility in predicting the behaviour and prognosis of urothelial carcinoma, with no significant difference in their expression between non Bilharzial and Bilharzial bladder carcinomas