Expression of epidermal growth factor receptor-1 in chronic schistosomal urinary bladder lesions

ABSTRACT

Over expression of growth factors including epidermal growth factor receptor [EGFR], have been implicated in bladder cancer biology. This study was conducted in a trial to a better understanding the genetic mechanisms underlying the proliferative, the premalignant and malignant changes frequently displayed in chronic schistosomal cystitis [ChSC] and schitosoma associated carcinoma of the bladder. The study included 58 Egyptian patients [15 ChSC and 43 bladder cancer], and 5 normal urothelial specimens as control. The bladder cancer specimens were selected included adjacent normal mucosa or dysplastic areas [27 squamous cell carcinoma SCC and 16 transitional cell carcinoma TCC]. Level of expression of EGFR was analyzed using an immunohistochemical approach and the results compared with histological pattern, grading and pathological staging. In normal epithelium EGFR expression was only limited to the basal layer, but in dysplastic epithelium adjacent to tumour tissue all cells stained for EGFR. Bilharzial associated TCC exhibit very low expression, EGFR expression was weak cytoplasmic or even absent. The majority of SCC expressed strong membrane staining for EGFR and almost all cells were positive for the receptor. However, the intensity of staining was increasing with a significant statistical correlation with grade [p < 0.01] and with invasiveness of the tumour [p < 0.001]. In conclusion over expression of EGFR [high intensity] in human bladder cancer may be associated with poor differentiation and with invasion that could be implicated in the pathway of oncogenesis for schitosoma associated SCC of the bladder