Steroid receptors in normal, hyperplastic and malignant human endometria.

Oestrogen and progestin receptors are present in the cytosol and nuclear compartments of normal human endometrium, partly associated with their endogenous ligand hormones. Receptor concentrations fluctuate in relation to the menstrual cycle. Hyperplastic endometrium tends to contain high concentrations of cytosol progestin receptor, whereas the levels of cytosol and nuclear progestin receptors in endometrial adenocarcinoma are lower than in non-neoplastic endometrium. The receptor levels seem to decline with decreasing differentiation of the tumour. Progestin treatment extending over several weeks decreases cellular oestrogen and progestin receptor content in both hyperplastic and malignant endometria. Information based on small patient series suggests that patients suffering from advanced or recurrent endometrial carcinoma and having significant concentrations of both receptors in the tumour tend to have a more indolent clinical course than patients with absent or low tumour receptors. Patients whose lesions are progestin receptor-rich more frequently respond to progestin administration than those with receptor-poor tumours. In contrast, patients with advanced or recurrent disease after progestin treatment and with low tumour oestrogen and progestin receptor concentrations respond more often to combination cytotoxic chemotherapy than patients with higher tumour receptor levels. More data are needed about the clinical correlates of receptor determinations in human endometrial carcinoma to confirm these encouraging preliminary results, before the clinical significance of the determinations can be settled. since there are marked differences in the receptor concentrations reported by various investigators, possibly for methodological reasons, comparison of receptor data and treatment results from different groups is sometimes very difficult.