Cytoplasmic steroid receptors in tumoral and “normal” endometrial samples from symmetrical uterine zones

Cytosol progesterone (PgR) and estradiol (E 2R) receptors were quantified simultaneously in “normal” and tumoral endometrium samples, located symmetrically on the longitudinal axis of the uterine cavity. With this experimental model two different groups of patients were detected. In the first group (7 of 10 women), the endometrial carcinoma had a greater cytosolic concentration of PgR than the corresponding “normal” endometrium, both kinds of tissue being affected by the same circulating hormonal “environment” peculiar to each patient. The opposite occurs in the other group (3 of 10 women), since the “normal” endometrium was found to be “richer” in receptors than the tumoral endometrium. It is suggested that this difference in the capacity of the tumor for synthesizing PgR and even E 2R as compared to the “normal” endometrium may be a marker which improves selection of patients who will be more likely to respond favorably to endocrine therapy.