Immunophenotypic Analysis of Colorectal Carcinomas with Monoclonal Antibodies 47D10 and Anti-Carcinoembryonic Antigen

Abstract

A series of 80 colorectal adenocarcinomas were analyzed immunohistochemically for the antigen recognized by a new monoclonal antibody (MCA) 47D10. These antigens are part of a complex family of substances similar to, yet distinct from carcinoembryonic antigen (CEA), and are termed nonspecific cross-reacting antigens (NCA). Formalin-fixed paraffin-embedded sections of colorectal adenocarcinomas were evaluated for the expression of these antigens and compared to the expression of CEA. Our study shows that 83.8% of the cases were positively stained for NCA while 91.3% were positive for CEA. Both antigens were coexpressed in 80% of the cases. No correlation was found between MCA 47D10 immunoreactivity and tumor grade, stage, size or location within the colon. In 25 cases, the benign colonic mucosa adjacent to the carcinoma stained positively with MCA 47D10. Normal colon does not express NCA as recognized by MCA 47D10, except in rare cells. Forty-eight of these cases had serum available for study. Both NCA and CEA were determined in these serum samples. Forty-two of these sera demonstrated elevated CEA levels, whereas only 8 showed increased levels of the 47D10 antigen(s). These findings suggest that the gene product(s) recognized by MCA 47D10 can be independently expressed or, more commonly, coexpressed with CEA in these tissues.

Immunohistochemical Analysis of Pulmonary and Pleural Neoplasms Using a Monoclonal Antibody (47D10) Which Reacts with Nonspecific Cross-Reacting Antigen

“…Monocytes, a closely related circulating form of tissue macro phages, have been found previously to be nonreactive with MAb 47D10 [7,11]. We tentatively suggest that the staining of mac rophages recorded in this study does not represent inherent antigenic expression by this cell type.…”

“…MAb 47D10 has been used previously to evaluated a series of 12 colon carcinomas, as well as in a larger survey study of colorectal ACs [7,11], The only normal tissues known to express the 47D10 antigens are granulo cytes and nonneoplastic colonic mucosa. Our data indicate that 42.3% of the lung tumors in this series expressed NCA.…”

“…The antigens detected by MAb 47D10 have been shown to be biochemically differ ent from CEA. The epitope detected by MAb 47D10 is not present on, but parallels the expression of CEA [7,11], Since MAb 47D10 does not cross-react with CEA, it would be of interest to know if NCA expres sion in pulmonary neoplasms correlates with the known expression pattern of CEA in the tumors.…”

Use of tumour marker immunoreactivity to identify primary site of metastatic cancer.

“…Although we could not determine the sensitivity of thyroglobulin, the specificity of about 100% agrees with previous results.' 4 The expression of ovarian tumours of the antigen CA125 is dependent on whether the tumour is serous or mucinous. "5 Serous ovarian tumours are generally consistent and strong expressors of the antigen whereas mucinous tumours may show no or only weak staining.…”