Carcinoembryonic antigen in gastric juice as an aid in diagnosis of early gastric cancer.

The levels of carcinoembryonic antigen (CEA) in the serum and gastric juice of 58 patients with gastric cancer were determined by radioimmunoassay. The level of serum CEA was not a satisfactory indicator of gastric cancer: it was elevated in only 19.4% of the cases of advanced and unresectable cancer and 4.5% of cases of early cancer examined. However, the CEA level in the gastric juice was significantly higher in patients with gastric cancer than in normal subjects or patients with benign gastric diseases: increased CEA concentrations and outputs in the gastric juice were observed in 54.5% and 40.1%, respectively, of the patients with early gastric cancer, and in 52.9% and 50.0%, respectively, of the patients with advanced gastric cancer. The gross type of gastric cancer had no influence on the gastric CEA level, but the CEA level in the gastric juice tended to be high when the tumors were large, or when they had little or no glandular structure or high mucus-secreting activity.