[Tissue carcinoembryonic antigen: a screening test for increased cell proliferation?]

A relationship between the tissue and serum concentrations of carcinoembryonic antigen (CEA) as determined by the enzymoimmunoassay (EIA) was studied in 46 patients with colorectal carcinoma and 47 patients with gastric carcinoma. The values were then compared to those obtained in the control group of 64 healthy subjects. Serum CEA concentrations were measured in all of them, whereas tissue CEA concentration was determined in the rectal and gastric mucosa homogenates in 30 and 34 subjects, respectively. As expected, no differences were observed in the levels of serum CEA concentrations in either of the healthy subject subgroups. The serum CEA concentrations were found to be at the normal level of 2.5 ng/ml. In both subgroups of healthy subjects, the tissue CEA concentration was found to significantly differ, but the same was in colorectal and gastric carcinomas as compared to the normal rectal and gastric mucosa. When the process extent according to Dukes' classification in 22 patients with colorectal carcinoma operated on was compared to the relationship between the tissue and serum CEA concentrations, the serum CEA concentration of CEA was shown to depend on the tumor mass, regardless of the level of the specific tissue CEA concentration. Unusually high values of tissue CEA concentration, along with normal serum CEA concentration, were observed in 3 healthy subjects. A relationship between the tissue and serum CEA concentrations according to the degree of differentiation, studied in colorectal carcinomas, revealed significantly lower values of tissue CEA concentration in poorly differentiated carcinomas (P less than 0.01), whereas serum CEA concentrations did not show any such difference.