Female sex steroid receptors in normal, hyperplastic and carcinomatous endometrium. The relationship to serum steroid hormones and gonadotropins and changes during medroxyprogesterone acetate administration

Abstract

AbstractOestrogen and progestin receptors were measured from the cytosol fraction of normal, hyperplastic and carcinomatous human endometrium. Hyperplastic tissue contained the highest progestin receptor concentrations, followed by proliferative and secretory endometrium. Adenocarcinoma tissue was characterized by a lower progestin receptor content, which was further related to the degree of tumour differentiation with well‐differentiated carcinomas containing higher receptor levels than the poorly differentiated ones. There were no major differences in the oestrogen receptor values among the various tissue groups, except that poorly differentiated adenocarcinomas tended to have lower receptor levels than the others. The majority (80%) of adenocarcinomas contained both oestrogen and progestin receptors, in contrast to breast cancers where only half of the tumours simultaneously possessed the two receptors. There was no statistically significant correlation between serum oestradiol‐17β, progesterone, FSH or LH values and cytosol oestrogen or progesterone receptor concentrations in the various groups. Medroxyprogesterone acetate treatment for an average of 4 weeks significantly reduced the concentrations of cytosol oestrogen and progestin receptors in hyperplastic and carcinomatous tissue. Progestin receptor concentration declined to 10–20% of the initial value during this short‐term medroxyprogesterone acetate treatment. The depression in the cytosol receptor content may be detrimental for a beneficial hormone action to occur during a long‐term progestin treatment of endometrial carcinoma.