Comparative study of CEA staining in gastric and colorectal cancer tissues.

Expression of CEA was studied in tissue sections from 140 cases of gastric and 54 cases of colorectal carcinoma by the immunoperoxidase technique. In some cases of gastric cancer, the intensity of CEA staining was compared with the CEA concentration by radioimmunoassay, and the intensity of the CEA staining was related to CEA concentration. CEA was more strongly positive in colorectal carcinomas than in gastric carcinomas. The intensity of the CEA staining was stronger in differentiated gastric and colorectal carcinomas than in anaplastic ones. No relationship was seen between the expression of CEA and the extent of disease in gastric or colorectal carcinoma. The CEA expression was related to the location of tumors in colorectal carcinomas, but not in gastric carcinomas.