CEA and NCA in benign and malignant breast tumors.

The involvement of Nonspecific Crossreacting Antigen (NCA) in the immunohistological demonstration of Carcino Embryonic Antigen (CEA) in 56 benign and 92 malignant lesions of the breast was analyzed. For this purpose, the authors utilized both polyclonal antisera and monoclonal antibodies. Polyclonal anti-CEA sera were used after absorption with normal tissue antigens, in order to remove crossreactivity, and without such an absorption. Ninety-three percent of breast carcinomas, 85% of mastopathic lesions not associated with a carcinoma, and 66% of fibroadenomas showed positive reactions with commercial unabsorbed polyclonal anti-CEA serum, which contained antibodies to NCA, whereas incubation with monospecific anti-CEA antiserum resulted in 42% positivity in carcinomas and negativity in mastopathic lesions and fibroadenomas. Forty-eight percent of breast cancer, 84% of mastopathic lesions, and 50% of the fibroadenomas contained NCA in different quantities. The staining pattern of carcinomas and fibroadenomas obtained with unabsorbed anti-CEA antibody and anti-NCA did not run parallel in all cases. Monoclonal antibodies against CEA and NCA confirmed the results obtained with polyclonal antiserum. This study suggests a cancer specificity of CEA in breast lesions.