Relationship between aromatase activity and steroid receptor levels in ovarian tumors from postmenopausal women

Aromatase activity, as well as steroid receptors, exists in nonfunctional ovarian tumors. Steroid receptor status has been reported to be related to prognosis in ovarian cancer patients. We determined aromatase activity and progesterone receptor (PR) and estrogen receptor (ER) levels in 43 ovarian tumors obtained from postmenopausal women. Aromatase activity was detected in 35 tumors (81%), PR in 21 tumors (49%) and ER in 13 tumors (30%). Eighty-three percent (10/12) of mucinous cystadenoma tissues showed positive PR with high aromatase activity, while 93% (13/14) of malignant tumors showed negative PR and low aromatase activity. Aromatase activity was detected in 95% (20/21) of PR-positive tumors, being greater than in PR-negative tumors (P < 0.002). There was a positive correlation between aromatase activity and PR (r_s = 0.49, P < 0.001). However, there was no correlation between aromatase activity and ER. In 17 patients (43%), the serum estradiol level was higher than 30 pg/ml and there was a positive correlation among estradiol, estrone, androstenedione and testosterone. However, serum steroid levels were not correlated with aromatase activity, PR or ER. Aminoglutethimide inhibited aromatase activity of benign and malignant ovarian tumors, uterine myoma, choriocarcinoma cells and purified human placental P-450arom in a similar manner. These results suggest that aromatase activity is correlated with PR in ovarian tumors of postmenopausal women. In addition to steroid receptor status, aromatase activity may be a useful prognostic factor in ovarian cancers.