Characterization of cell types in human breast tumor primary cultures

Primary cultures of cells from breast carcinomas were attempted in 74 cases. Growth was observed in 46 cases. Using immunochemical demonstration of keratin proteins (KER), epithelial membrane antigen (EMA) and carcinoembryonic antigen (CEA), three morphologically distinct cell populations were characterized and described. Two cell types (E- and E'-cells) were identified as epithelial by their positive staining for KER and EMA. The third type (F cells) displayed a negative staining for these two epithelial markers; they were considered as stromal cells (fibroblasts). More than 50% of the cultures consisted of pure epithelial cells. Positive CEA staining was observed only in KER- and EMA-positive cells. Out of the 30 cultures, 15 displayed positive staining for CEA. In 7 of these, 30-50% of cells displayed positive, diffuse staining for CEA. The other 8 cultures consisted of more than 50% CEA-positive cells. Strong and homogeneous positivity was restricted to the E-cells, while in the same cultures, E'-cells displayed heterogeneous and diffuse staining. Efficiency and value of this cell culture system are discussed, in comparison with other human breast tumor cell (HBTC) culture techniques. Identification of growing cells and cellular composition of primary cultures are emphasized.