CEA and HMFG in hyperplastic and malignant lesions of the breast.

In order to evaluate a possible transition from proliferative lesions of the breast to ductal carcinoma in situ (DCIS), an immunohistochemical retrospective analysis was carried out. Twelve patients with hyperplasia without atypia, 11 patients with hyperplastic lesions with atypia, 21 patients with DCIS and 24 patients with invasive carcinoma were studied. The expression of carcino-embryonic antigen (CEA), a dedifferentiation marker, was investigated, applying one monoclonal antibody (Amersham). The expression of human milk fat globulin (HMFG), a differentiation marker, was studied by means of three monoclonal antibodies. The results reveal that no CEA activity can be demonstrated in normal and hyperplastic breast tissue, either with or without atypia. The monoclonal antibody was positive in 48% of DCIS and 50% of the invasive carcinomas. We failed to observe a correlation between the presence of CEA and the differentiation of the tumor. The application of this antiserum adds no substantial information about the phenotypic alterations during the progression from atypical hyperplasia to DCIS. HMFG was present in benign as well as in malignant breast lesions. Therefore, we conclude that HMFG is not useful for the evaluation of the phenotypic change from atypical hyperplasia to malignancy. However, as pointed out by others, it can be used in a diagnostic panel of different antibodies in the distinction between epithelial and non-epithelial lesions.