Estrogen and progesterone receptors in tumors of the human ovary

A total of 23 malignant ovarian tumors and 5 benign or tumor-like lesions of the ovary had their estrogen receptor (ER) status, and of these 15 also had their progesterone receptor (PR) status, determined. Tumors were said to be ER+ when the receptors bound >4 fmole estradiol/mg protein and PR+ when they bound >10 fmole progesterone/mg protein. Ten of twenty-two ovarian carcinomas were estrogen receptor positive (ER+) and 3 of these also contained progesterone receptors (PR+). All 6 malignant ovarian tumors occurring in premenopausal women were ER? and PR? as were the two benign tumors occurring in two premenopausal patients. It may be that premenopausal women have tumors which are more frequently ER? PR? because their higher blood hormone levels block the estrogen and progesterone binding sites in the tissues. It was not possible to show any variation from normal in the plasma hormone levels (estradiol, estrone, testosterone, progesterone, FSH). It is suggested that hormone receptor studies of malignant ovarian tumors could aid in the selection of patients suitable for therapies based on endocrine manipulation.