Monoclonal antibodies applied to primary human breast carcinoma: Relationship to menopausal status, lymph node status, and steroid hormone receptor content

Abstract

Monoclonal antibodies were raised against purified human milk fat globule membranes. The binding of three of these (Mam-3, HMFG 1, and HMFG 2) to fixed histological sections of 100 primary breast carcinomas has been investigated. Tissue specificity was investigated by testing the binding of the antibodies to carcinomas from other organs and to benign proliferative breast lesions. In breast tissue, antigens were found only in the epithelial cells, while the stromal component, myoepithelium, and any inflammatory cells present were negative. The reaction was characterized by considerable heterogeneity, both with regard to the percent of cells positive and the intensity of the reaction. No relationship was observed between binding and histological type of breast carcinoma. However, in ductal infiltrating carcinomas, a tendency towards a greater proportion of tumors that bound the antibodies was observed among the highly differentiated compared to the low differentiated carcinomas. Data on estrogen and progesterone receptors were available in 53 and 22 of the 100 carcinomas, respectively. There were no apparent relationships between the presence of surface antigens and the menopausal status, lymph node status, or estrogen receptor status, but the tumors lacking progesterone receptor apparently lacked the antigens as well. The presence of surface antigens probably defines a differentiation in primary breast carcinoma. Whether this differentiation is of any prognostic significance remains to be established.