Cytosol oestradiol and progesterone receptors in endometrial hyperplasia and adenocarcinoma: determination by single saturating dose exchange assays.

Available oestradiol and progesterone binding site concentrations in endometrial cytosols were determined by simplified single saturating dose assay in 16 normal women with proliferative endometrium, in 10 patients with endometrial hyperplasia, and in 20 patients with endometrial adenocarcinoma. The mean oestrogen receptor level tended to be higher in endometrial hyperplasia than in either proliferative or carcinomatous endometria. Mean progesterone receptor levels were comparable in proliferative and hyperplastic endometria, but were sequentially lower in highly differentiated carcinoma, moderately differentiated carcinoma, and undifferentiated carcinoma. Correlation between results obtained by single saturating dose assays and by conventional Scatchard analysis in those endometria subjected to both procedures was high for both oestrogen (r = 0.998) and progesterone (r = 0.949) and indicates that with the simplified assays, large scale clinical studies on hormone sensitivity of endometrial adenocarcinomas are feasible.