[Immunohistochemical localization of carcinoembryonic antigen (CEA) in gastric cancer--a comparative study between...

Plasma carcinoembryonic antigen (CEA) was examined in 122 cases of gastric cancer and immunohistochemical localization was also studied in 102 resected specimens. A comparative study between tissue CEA and plasma CEA was carried out. The results were as follows. Plasma CEA were positive (over 2.5 ng/ml) in 46 cases (37%). The positive rate was parallel with the size of cancer (p less than 0.05) and was higher in well-differentiated cancer. As to tissue CEA, 87 specimens (85%) showed the varying degree (+/- +) of positive reaction. CEA was localized in luminal border, cytoplasma and grandular lumen in well differentiated cancer, and only in cytoplasma in poorly differentiated cancer. The positive rate of plasma CEA was parallel with the degree of positive reaction in tissue. No significant histological difference was observed between strong positive reaction to tissue CEA and positive plasma CEA. In the cases with moderate positive reaction to tissue CEA, however, the positivity of plasma CEA was significantly higher in the cases with alpha or beta INF pattern and/or intermed stromal reaction. (p less than 0.05).