[Expressions of estrogen receptor subtypes in epithelial ovarian carcinomas]

To investigate the expressions of estrogen receptor(ER) subtypes ERa and ERP in epithelial ovarian carcinomas.

One hundred and eighteen Norwegian patients with epithelial ovarian carcinoma were included in this study. The expressions of ERalpha and ERbeta were examined by means of immunohistochemistry. The relationships between protein expressions and clinicopathological features and survival were analyzed. Frozen tissues from 10 cases in which the tumors showed variable ERalpha and ERbeta protein expressions were used for Laser capture microdissection (LCM). Cancer cells in each frozen section were captured with the LCM method and processed for Western blot analysis.

Of the 118 tumours, 32 (27.1%), 20 (16.9%), 17 (14.4%), 49 (41.5%) demonstrated negative, weak, moderate and strong expression of ERalpha protein, respectively; 1 (0.8%), 7 (5.9%), 13 (11%), 97 (82.2%) showed negative, weak, moderate and strong expressions of ERbeta protein, respectively. There was no significant association between ERalpha expression and the clinicopathological features such as age, histological type, FIGO stage, histological grade and residual tumour size. ERbeta expression was not associated with age, histological type,FIGO stage and residual tumour size, but it was significantly associated with higher histological grade. In addition, Kaplan-meier analysis revealed that high levels of ERbeta expression was significantly associated with a shorter overall survival (P = 0.03).

There are ERalpha and ERbeta expressions in epithelial ovarian carcinomas. Higher level of ERbeta protein expression is associated with higher histological grade and poorer clinical outcome in the cases of ovarian carcinoma. ERbeta may be a useful marker of ovarian carcinogenesis and could predict the efficacy of endocrinotherapy and the prognosis for patients with ovarian carcinoma.