IMMUNOHISTOCHEMICAL STUDY OF ETS-1 ONCOPROTEIN EXPRESSION IN UROTHELIAL (TRANSITIONAL CELL) CARCINOMAS OF THE URINARY BLADDER

Abstract

SUMMARY ladder cancer (BC) is the ninth most common cancer worldwide. In the Western world, bladder cancer is the fourth most common malignancy in men and the eighth most common in women. BC is one of the most common cancers in the Middle East countries. Egypt has both higher frequency and incidence rates than other countries. Egyptian males are almost two folds affected higher than in Western countries. Also, Egyptian males have higher mortality rates. At the time of diagnosis, urothelial tumors can be classified histopathologically into 2 groups: non-muscle invasive papillary tumors (Ta & T1) and muscle invasive tumors. Many prognostic parameters related to tumor recurrence and progression have been investigated; however, no reliable parameters have been identified for predicting the risk of recurrence or progression. The ETS-1 protooncogene is a transcription factor that has a role in extracellular matrix (ECM) remodeling. It can play a role in tumor progression by activating the transcription of some proteases including matrix metalloproteinases (MMPs) and urokinase-type plasminogen activator. These proteases account for ECM degradation, which is a key event in invasion. The aim of this study was to evaluate the significance of ETS-1 expression in urothelial carcinoma of the urinary bladder B Summary 137 and determine the relationship of this oncoprotein with the histopathological parameters including tumor grade and stage. The material of this study included 50 cases of primary malignant transitional cell carcinomas of the urinary bladder obtained by TURBT. The mean of the patients’ age was 57.5 years with a male to female ratio of 3.54:1. There was a 20% association of the cases with bilhariziasis. Correlation between tumor grade and stage and patients’ age and sex revealed a non significant relationship. The low grade of differentiation of bladder cancer was more than the high grade, where 56% of the cases were low grade while 44% of the cases were high grade. Regarding the depth of tumor invasion, invasion of the muscularis propria (pT2) was the most common representation (58%). All cases were subjected to histopathological evaluation and ETS-1 immunohistochemical staining. Evaluation of ETS-1 expression was carried out by analyzing the extent of staining positivity of the tumor cells. ETS-1 was widely expressed in both the cytoplasm and nucleus of the carcinoma cells. IHC staining for ETS-1 in TURBT specimens revealed that the majority of low-grade and noninvasive urothelial Summary 138