Immunohistological investigations of carcinoembryonic antigen (CEA) in urothelial carcinomas

CEA is discussed as a potential tumour marker for carcinomas of the urothel ium. However, investigations by means of polyclonal antibodies have shown v arious cross reactions which are not to be expected with monoclonal antibod ies (MAb). Immunohistochemistry was done with the MAb anti-CEA BW 431/26 (B ehring), N 1522 (Dako), and C 7292 (Sigma) on 37 carcinomas of the urotheli um (grades 1-3). The MAb BW 431/26 showed the best results concerning speci fity and sensitivity. In general, immunohistological investigations demonst rated negative or moderate staining reactions. Positive reactions were seen in 32 % (12/37) of the carcinomas. Staining intensity for CEA correlated w ith differentiation grade. On the whole, a maximum of 5 % of the tumour cel ls were CEA positive. Our results indicate that monoclonal anti-CEA antibod ies are not usefull as a tumour marker for urothelial carcinomas. For the s uitability of CEA for in vitro and for in vivo diagnosis a threshold of CEA positive tumour cells has to be defined.