ABSTRACT
Immunohistochemical tissue expression of the anti- proliferative marker P21 and the oncogenic marker C-myc were estimated in 40 cases with non-neoplastic and neoplastic urinary bladder lesions with or without schistosomal infection to assess the significance of their expression as a diagnostic tool in patients with higher risk of developing cancer bladder. P21 expression was detected in 50% of simple cystitis cases and all cases with premalignant changes were positive for P21 immunoreactivity expressed into about 16% of urothelial cells. Eighty-five% of malignant cases expressed P21 in 48-55% of urothelial cells without significant variance between different histologic tumor types. Extent of P21 expression inversely correlated with bilharzial association, upgrading of malignancy and tumor invasiveness. C-myc was detected in 80% of simple chronic cystitis cases [75% cytoplasmic, 25% cytoplasmic and nuclear expression] and in all cystitis cases with premalignant changes [as cytoplasmic and nuclear expression]. Eighty-nine% of cancer cases were C-myc positive with predominance of nuclear expression to be seen in 16.74 and mixed with cytoplasmic expression in another 58.3% of positive cases. Malignancy upgrading and invasiveness raised C-myc positivity. It was concluded that P21 expression increases in an attempt to check cellular proliferation, while the increase in the oncogen C-myc goes ahead. Loss of P21 and increased C-myc expression in a malignant lesion is a predictor of malignancy progress to higher grade or stage