IMMUNOHISTOCHEMICAL DETECTION OF BREAST SPECIFIC ANTIGENS AND CYTOKERATINS IN METASTATIC BREAST-CARCINOMA IN THE LIVER

The present study was performed to evaluate the diagnostic reliability of antibodies to breast carcinoma-specific antigen and antibodies to cytokeratin catalogue in a metastatic hepatic lesion. Immunohistochemi cal examinations using antibodies to gross cystic disease fluid protei n-15 (GCDFP-15), BCA-225 (a glycoprotein secreted by T47D breast carci noma cell line) and BRST-5 (a glycoprotein identified in SK-BR-7 breas t carcinoma cell line), anti-cytokeratin monoclonal antibodies of MA90 4, AE3, CAM5.2, PKK1 and cytokeratin 19, and polyclonal anti-keratin a ntibodies were done. These were on 15 cases of primary breast carcinom a, eight cases of metastatic breast carcinoma in the liver, five cases of cholangiocarcinoma, eight cases of hepatocellular carcinoma and 11 cases of metastatic adenocarcinoma of another primary tumor in the li ver. Results showed that GCDFP-15 antigen was most reliable: it was 10 0% positive in both primary and metastatic breast carcinomas unrelated to histological subtypes, and 100% negative in primary or other metas tatic carcinomas in the liver. BCA-225 antigen was detected in high am ounts in breast carcinomas (100%, 23/23), but it was positive in chola ngiocarcinomas (80%, 4/5) and another metastatic carcinoma in the live r (64%, 7/11). BRST-5 was specifically positive in breast carcinomas b ut the positivity was low (13%, 3/23). Cytokeratin 19 and keratin were useful to discriminate hepatocellular carcinomas (0%, 0/8) from breas t carcinomas (87%, 20/23; 96%, 22/23), but they were also positive in cholangiocarcinomas (100%, 5/5) and other metastatic carcinomas in the liver (91%, 10/11). AE3, CAM5.2 and PKK1 showed highly positive immun oreactivity for breast carcinomas, cholangiocarcinomas and other metas tatic carcinomas in the liver, and hepatocellular carcinoma cells were sometimes stained (50%, 4/8; 88%, 7/8; 38%, 3/8). MA904 showed negati ve immunoreactivity for all cases examined. A discussion was made on t he specificity of the antibodies available for a histologic differenti al diagnosis.