Distribution of carcinoembryonic antigens and blood group substances in adenocarcinoma of the colon.

Immunoperoxidase techniques were used to localize carcinoembryonic antigens (CEA) and human blood group substances (BGS) in 41 adenocarcinomas of the colon and 15 metastases or recurrences of these tumors. Ten primary tumors (24 per cent) were strongly positive for both antigens, 12 (29 per cent) were positive for BGS only, 11 (27 per cent) were positive for CEA only, and eight (20 per cent) contained only microscopic amounts of either. With few exceptions, individual tumor cells contained either CEA, BGS, or neither, but not both. Cancers of the left colon which were positive for BGS were associated with a lower frequency of metastases than were those without BGS (p less than 0.01); tumors lacking both CEA and BGS metastasized more frequently than those tumors containing either or both antigens (p less than 0.01). In tumors of the right colon, there was no significant correlation between antigen content and frequency of metastases. In three cases, the development of recurrent or metastatic tumor was associated with a loss of BGS positivity. The data suggest that immunohistochemical studies of BGS and CEA may be of value in estimating the clinical behavior of certain colon carcinomas.