Expression of Ca antigen on human urinary bladder tumors.

Flow cytometric measurements of Ca antigen (Ca) visualized by immunofluorescence with Ca1 monoclonal antibody (Ca1) were performed on cells from 26 urinary bladder carcinomas of various histologic grades and DNA ploidy and on 6 samples of morphologically normal urothelium. In normal urothelium and in the 14 diploid tumors the proportion of positively staining cells was low and the differences were not statistically significant. A significant increase in the proportion of fluorescent cells was observed in all but one of the 12 aneuploid tumors. Among the 11 tumors with an increased proportion of positive cells, 7 were invasive. Data recorded in this study suggest that the quantitation of Ca1 fluorescence corresponding to the presence of Ca may prove to be helpful in the evaluation of clinical behavior of bladder tumors.