[Measurement of estrogen receptor and progesterone receptor in human endometrium and endometrial carcinoma]

The concentration of cytosol estrogen receptors (ER) and progesterone receptors (PR) in the endometrium of the normal menstrual cycle and endometrial carcinoma, were measured by Enzyme Immunoassay (EIA) using monoclonal antibody, and were compared with Dextran Coated Charcoal (DCC) method. In DCC method, maximum binding sites were estimated according to Scatchard plot analysis. Following results were obtained in this study. 1) In the normal endometrium obtained from 20 cases, the correlation coefficients for ER and PR were 0.907 and 0.778, respectively. Regression lines were as follows; ER (EIA) = 1.68 (DCC) + 19.1 fmol/mg protein and PR (EIA) = 0.13 (DCC) + 24.8 fmol/mg protein. A good correlation was found between the two methods in ER assay. 2) In the normal menstrual cycle, DCC values and EIA values of ER were increased in proliferative phase, and were decreased in secretory phase. DCC values of PR were increased in proliferative phase and not decreased in secretory phase, but EIA values of PR were not remarkably changed. 3) In the endometrial carcinoma obtained from 14 cases, there was good correlation between EIA and DCC values in ER assay (r = 0.941), but correlation between the two methods was not found in PR assay. 4) In relation of histology, positive rates were highest in patients with well differentiated types, and in relation of clinical stage, positive rates were higher in the patients with early stages than progressive stages. These results suggest that EIA is as useful as DCC in ER assay in normal endometrium and endometrial carcinoma.