Estrone and estradiol content in human breast tumors: Relationship to estradiol receptors

Abstract

We have measured the estradiol receptor content together with the endogenous estrone and estradiol concentrations in human breast tissue cytosols. There was no evidence for a relationship between high estrogen levels and low receptor measurements. Receptor positive tumor cytosols contained a statistically significant greater estradiol concentration than those of receptor negative tumors or of normal tissue. This was confirmed in a study of sixteen pairs of tumor and normal tissue from the same breast in which the estradiol but not estrone concentration of the receptor positive tumors exceeded that of its normal partner. The results indicate that (a) false negative receptor assays due to the presence of endogenous estrogens are not likely; (b) receptor positive tissues retain greater amounts of estradiol than receptor negative tumors.