Primary cultures of human benign mastopathies and mammary carcinomas; growth factor requirements.

Primary cultures of non malignant human breast tissues, benign mastopathies and breast carcinoma were performed in defined culture conditions. Epithelial cells from these primary cultures were characterized for mammary epithelial cell specific markers, for in vitro cell proliferation, for steroid receptors and hormone sensitivity (estradiol, progesterone and prolactin) and for EGF sensitivity. We show that although some mastopathies have estradiol and progesterone receptors, they did not respond to hormone treatment. Human prolactin had no effect on the proliferation of one mastopathy but stimulates the cell growth of another fibrocystic mastopathy. EGF was capable of stimulating the three types of primary cultures. As regards growth characteristics, steroid hormone receptors and prolactin sensitivity, phenotypes of mastopathy cells differ from each other; some are similar to non malignant cells, whereas others are comparable to tumor cells.