Comparison of cytosol estrogen and progestin receptor status in malignant and benign tumors and tumor-like lesions of human ovary

Some human ovarian malignancies respond favorably to hormone therapy. In order to obtain more information about the endocrine properties of these malignancies, we measured estrogen (ER) and progestin (PR) receptors in 21 malignant ovarian tumors, and compared the findings with those in 29 benign tumors and 28 tumor-like ovarian lesions. There were marked differences in steroid receptor distributions between the three groups. Only 38% of the malignant tumors simultaneously contained measurable amounts of both receptors, whereas the corresponding figure was 76% for the benign tumors. Malignant tumors were more often (29%) receptor-negative than the benign ones (7%). The major difference in the tumor-like lesions was the high frequency (43%) of samples containing PR only, as compared with the two other groups. The respective concentrations (fmol/mg cytosol protein, mean ± SEM) of ER and PR were 114 ± 42 and 148 ± 76 (malignant tumors), 71 ± 34 and 132 ± 32 (benign tumors) and 19 ± 16 and 251 ± 88 (tumor-like lesions). Of the malignant tumors, endometrioid carcinoma was characterized by a relatively high mean PR content (330 ± 262), whereas in undifferentiated carcinoma a high ER content (149 ± 97) was associated with a low PR concentration (26 ± 15). Steroid receptor content was very similar in benign epithelial tumors with different histological properties. The two main groups of tumor-like lesions, endometriosis and luteal cysts, typically contained little or no ER and a relatively high amount of PR. Hormone dependency of malignant and benign ovarian tumors and tumor-like lesions does not seem similar. These data support the notion that receptor determinations from malignant ovarian tumors could aid in selection of patients for endocrine therapy in a manner similar to that already established for certain other hormone-dependent cancers.