Estrogen Receptor Alpha Expression in Ovarian Cancer Predicts Longer Overall Survival

Estrogen as a potential factor of ovarian carcinogenesis, acts via two nuclear receptors, estrogen receptor alpha (ER alpha) and estrogen receptor beta (ER beta), but the cellular signal pathways involved are not completely clear so far. In this study we have described the expression of ER alpha, detected by immunocytochemistry in 11 ovarian carcinoma cell lines and by immunohistochemistry in 43 Federation Internationale des Gyneacologistes et Obstetristes stage III ovarian carcinoma specimens prepared before and after treatment with cisplatin-based schemes. For cisplatin resistance is a major obstacle in the treatment of ovarian carcinoma, analysis of cisplatin sensitivity in 11 ovarian carcinoma cell line was also performed. The strong nuclear ER alpha expression was only shown in the single A2780P cell line. Expression of ER alpha in tissue specimens did not reveal any correlations between histopathological parameters (histologic type and grading). We demonstrated a significant association with ER alpha expression in specimens from primary laparotomies (PL) and cause-specific survival. In the cases terminated by death of the patient, overall immunoreactivity score of ER alpha expression at PL was significantly lower than in surviving patients. In addition, Kaplan-Meier analysis revealed significantly shorter overall survival time and progression-free time in cases with lower immunoreactivity score of ER alpha expression at PL. Our findings support the hypothesis that aberrant hormone activity, by way of altered receptor expression, might be an important factor in the malignant transformation of ovarian cancer.