Immunohistochemical study of the human 17 beta-hydroxysteroid dehydrogenase and steroid receptors in endometrial adenocarcinoma.

17 beta-Hydroxysteroid dehydrogenase (17HSD) and estrogen (ER) and progestin (PR) receptors were analyzed immunohistochemically in tissue specimens of 66 patients with endometrial adenocarcinoma. Plasma steroid concentrations were correlated to immunohistochemical data. 17HSD was detected in 48% of the specimens and was stained in the cytoplasm of epithelial cells. The tissues were characterized by a heterogeneous staining pattern for 17HSD. In some patients, intensively stained epithelial cell clusters were seen, indicating that local factors were responsible for the expression of the protein. Poorly differentiated adenocarcinoma specimens tended to have no 17HSD more frequently than did well or moderately differentiated tissues. ER and PR were detectable in 24% and 28% of patients, respectively, and were localized in the nuclei of epithelial and stromal cells. There was a significant correlation between 17HSD and PR staining and an inverse correlation between plasma progesterone concentrations and 17HSD staining. This is contrary to the data obtained with normal endometrium. The main reason for this inverse relation between endometrial 17HSD staining and plasma progesterone concentrations was that, in some postmenopausal patients with low plasma progesterone concentrations, intense staining for 17HSD was detectable in the endometrial carcinoma specimens. This indicates a major difference in the regulation of 17HSD expression in endometrial adenocarcinomas, compared with normal tissues of premenopausal women.