Estradiol and progesterone receptors in human breast cancer.

: The concentration of estradiol and progesterone receptors in tumor cytosol from human breast cancer patients represents an important factor for the selection of patients for endocrine therapy and for the prognosis of the disease. This report presents results obtained by measurement of estradiol receptor in 157 breast tumors by the dextran coated charcoal method in media containing sodium molybdate (102 cases) or glycerol (55 cases). Results obtained when these two reagents were present separately in the assay media were similar, at least when the frequencies of estradiol receptor positive cases and the mean values for estradiol receptor concentrations were compared. Concomitant analyses for estradiol and progesterone receptors were done in 25 primary mammary carcinomas by the method of dextran coated charcoal using single saturating doses of hormones and cytosols obtained in a glycerol containing buffer. The results are discussed in relation with the steroid hormone mechanism of action.