Evaluation of epidermal growth factor receptor, carcinoembryonic antigen and Lewis carbohydrate antigens in human colorectal and liver neoplasias.

The expression of LewisY related carbohydrate antigens and the content of epidermal growth factor receptor (EGF-R), the carcinoembryonic antigen (CEA) and the alpha-fetoprotein (AFP) in colorectal and liver tumors were determined. These included 30 large bowel adenocarcinomas (7 colon, 6 sigma, 5 caecum, 12 rectum), 12 hepatocellular carcinomas and 6 liver metastases. Histologically normal tissue excised along with the tumors were used as controls. All plasma membranes studied showed specific EGF binding, and tumor plasma membranes had an EGF receptor level higher than that of the normal counterpart. However, EGF-R was positive in only a few tumors, and no correlation between clinical stages and grades of differentiation was observed. Cytosol CEA was higher in tumors than in normal counterparts. Tissue AFP and CEA content was different in liver hepatocellular carcinomas and in liver metastases. They are good markers to differentiate between primary and secondary liver neoplasias. The LewisY and related carbohydrate antigens, evaluated by the reactivity of the tissues to monoclonal antibody MAb B3, are expressed in liver metastases from colorectal adenocarcinoma. MAb B3 failed to react with hepatocellular carcinomas and with peritumoral liver tissues obtained from both metastatic and primary tumor lesions. These data suggest that immunoblotting with MAb B3 may be useful to obtain more information on liver carcinomas. Furthermore, MAb B3 or CEA armed with toxin in the form of recombinant immunotoxin or linked to a radionuclide can be useful in new treatments of metastatic lesions, such as immunotherapy, radioimmunotherapy and radioimmunoguided surgery.