[Morphometric, cytochemical and immunohistochemical studies on the proliferative activity of urinary bladder...

58 carcinomas of the urinary bladder as well as 11 carcinomata in situ and 10 biopsies of normal mucosa were investigated for their proliferative activity by means of nuclear area morphometry, silver staining of nucleolar organizing regions (NOR) and immunohistochemical staining of the proliferating cell nuclear antigen (PCNA) and the Ki67 antigen. In comparison to normal bladder mucosa, the values were increased significantly (p < 0.05) in all carcinomata in situ and carcinomas. Within the carcinomas, there was an increase from G1- to G3-carcinomas. For all four parameters, the values of the carcinomata in situ and the G2-carcinomas were similar. All parameters correlated with each other and allowed a significant differentiation between G1- and G2-carcinomas (p < 0.05), whereas they allowed only a less optimal differentiation between G2- and G3-carcinomas. Of all markers of proliferation, the Ki67 antigen was the most useful criterium to differentiate between invasive and noninvasive carcinomas. A Ki67 index of 30% seems to be a borderline between these two groups. This could be of prognostic relevance especially for the heterogeneous G2-carcinomas.