[Immunohistochemical study of Y hapten and carcinoembryonic antigen in rectal carcinoma]

The monoclonal antibodies C14 and C365 which define the Y hapten and specific carcinoembryonic antigen (CEA) were shown by ABC-immunohistochemical technique to stain positively the tissue sections in 48 of 56 cases (85.7%) of rectal carcinoma for Y hapten, in 51 cases (91%) for CEA, and 100% for both together. Cancer cells which expressed Y hapten were mainly distributed in the foreland and deep invading cancer tissue which showed high ability of malignant growth. Two patterns of localization on the cancer cells for Y hapten were found: local distribution in cytoplasmic Golgi region, similar to blood group antigens, and diffused distribution on the membrane and in the cytoplasm as CEA. Positive expression of Y hapten on the carcinoma associated with types of differentiation and Duke's pathology stages: highly expressed on the poorly differentiated cancer and in Duke's A and C stages (P less than 0.05). Phenotypes of Y hapten and CEA on metastatic cancer cells in lymph nodes and primary cancers were similar. Our findings indicate that the antibodies may be useful in immunodiagnosis and immunotherapy.