IMMUNOHISTOCHEMICAL LOCALIZATION OF AROMATASE AND ITS CORRELATION WITH PROGESTERONE RECEPTORS IN OVARIAN EPITHELIAL TUMORS

Aromatase cytochrome P-450 was immunohistochemically localised exclusi vely in the cytoplasm of neoplastic cells of benign and malignant nonf unctional ovarian tumours, whilst (progesterone receptors (PR) and est rogen receptors) (ER) were localised exclusively in the nuclei of neop lastic cells. Aromatase activity and PR were detected in 68% (17/25) a nd 32% of the malignant tumours and 82% (22/27) and 67% of the benign tumours, respectively. In postmenopausal tumours, the positivity for P R in malignant tumours was less frequent (p<0.01) than that in benign tumours. The tumours in which both aromatase and PR were positive, wer e less frequent (p<0.05) in malignant than in benign tumours. Aromatas e activity was detected in 100% (8/8) of the PR-positive tumours but i n only 68% (9/17) of the PR-negative tumours. With postmenopausal mali gnant tumours, there was a positive correlation between aromatase acti vity and PR level (r=0.77, p<0.001). However, there was no significant difference in the positivity for ER. The serum steroid levels did not correlate with the tumour levels of aromatase activity, PR or ER. The se findings suggest that aromatase activity is correlated with PR in o varian tumours of postmenopausal women. In addition to steroid recepto r status, aromatase activity may be a useful factor in ovarian cancers .