Cellular content of carcinoembryonic antigen in urothelial carcinoma

CEA containing cells can be demonstrated in 25--60% of urothelial carcinomas. No staining was seen with benign urothelial cells. Using microfluorometry of single cells, mean fluorescence intensity with anti-CEA antisera was 3--6 times that of preparations stained in parallel with nonimmune sera. A comparison of the IF results with RIA implies a possibility to detect less than 1 pg CEA/cell in unfixed specimens. The cells which stained with anti-CEA antisera did not have any apparent morphologic properties differentiating them from neighboring nonstained cells but it was mainly in the cell populations from well- and moderately well-differentiated tumors that CEA containing cells were seen. Therefore quantitative measurements of CEA amount/cell may be a parameter, in addition to morphologic differentiation, to study new properties of tumor cell populations.