[Immunoreactive carcinoembryonic antigens in gastric juice collected during endoscopy--their usefulness in the diagnosis of gastric cancer].

In the 109 subjects adopted for study, 52 involving gastric cancer and 57 noncancerous gastric disease, immunoreactive CEA (GI-SEA) in the gastric juice collected during endoscopy was measured by enzyme immunoassay using polyclonal (P group) and monoclonal (M group) antibodies against CEA. The results are outlined below. The mean value and the positivity of GI-CEA was the highest in advanced gastric cancer, followed by early gastric cancer and noncancerous gastric disease, in that order, and a particularly significant difference (P less than 0.001) was noted (in both the P and M groups) between the former two and the latter. In the GI-CEA of gastric cancer, high positivity was manifested regardless of the histological type, though the average values show that, in the case of the P group, high positivity manifested itself in undifferentiated adenocarcinoma, while in the case of the M group, it applied to differentiated adenocarcinoma. Moreover, no correlation was found between the size of the lesion and the positivity, though even with small lesions of less than 2 cm, there was an indication of probable high positivity. The values recorded for the P and M groups showed a close correlation between the two, except for the GI-CEA value of the histological type. However, for the M group, the positivity and GI-CEA value both tended to be low. The above results suggest that measurement of GI-CEA is of great help in the diagnosis of gastric cancer and that the use of polyclonal antibodies is appropriate for screening and early diagnosis.