Carcinoembryonic (CEA)--like antigen in adenomas and cancers of the breast in human patients.

By using specific anti-CEA serum and indirect immunofluorescence, a substance was detected in breast cancers which reacted similarly to CEA demonstrable by the same method in cancers of gastrointestinal tract. However, the double diffusion test in agar gel and additional absorption analysis showed that it was a glycoprotein different from CEA, although possessing common or similar antigenic determinants with it. This antigen also differs from another antigen called "nonspecific cross-reacting antigen NCA" and from alpha 1-acid glycoprotein of human serum.