[Changes of hormone receptor status in various treatment for human breast cancer and DMBA tumor of the rat].

Estrogen receptor (ER) and progesterone receptor (PgR) were measured by sucrose gradient centrifugation before and after various therapies, such as radiation, chemotherapy and hormone therapy. The subjects were 18 advanced or recurrent human breast cancers and 51 DMBA-induced mammary tumors of female SD rats. Changes of hormone receptors and the relationship between receptor levels and the effects of the therapies were examined. Changes of tumor cellularity were also studied in human breast cancers. Some ER-positive tumors changed into ER-negative and others did not. Most ER-negative tumors did not change in ER status. In the responsive cases, receptor levels tended to decline more remarkably and the cellularity of human breast cancer decreased.