[Relation between hormone dependency and the estrogen receptor of mammary carcinoma--comparative study of rat and human mammary tumors].

A comparative study of rat and human mammary tumors was undertaken to clarify the mechanism of hormone dependency by the PAP method. In normal mammary glands, histological estrogen receptor ER (+) cells were observed in the ductal epithelium and acinal cells, while only ER (-) cells were noted in HAN. After overiectomy, 55.6% of the ER (+) cells changes to ER (-). Furthermore, histological changes were glandular atrophy, anaplastic changes, (with) the remaining ER (+) cells (being in the) insular group. Those ER (+) cancer cells seem to be different in hormone sensitivity. As for human mammary glands, proliferation of ER (+) cells was observed in papillary lesions as duct papillomatosis. In the cancer tissues as a whole, ER (+) and ER (-) cancer cells were mixed, showing a so-called mosaic pattern.