Estrogen receptor subtypes in ovarian cancer - A clinical correlation

OBJECTIVE: To study the distribution, of estrogen receptor (ER) subtypes in ovarian tumors and to correlate the levels of expression with clinical factors. METHODS: Estrogen receptor-alpha (ER alpha) and beta-mRNA expressions in 58 normal, 25 borderline, and 161 malignant ovarian tissue samples were determined by quantitative real-time polymerase chain reaction. The expression levels were correlated with clinical data, including the histologic subtypes, the stage of the disease, and the disease-free and overall survival, with a median follow-up of 80 months. RESULTS: Estrogen receptor-beta (ER beta) expression, but not ER alpha, was significantly higher in normal tissues compared with malignant tissues (P<.001). Estrogen receptor-beta expression was also significantly higher in stage I disease compared with stage II-IV disease (P<.001). A higher ER beta expression was found to be significantly associated with a longer disease-free survival (P=.007) as well as overall survival (P=.011). Estrogen receptor-beta expression remained a significant predictor for disease-free survival and overall survival in multivariable analysis that took into account other factors that were shown to be associated with survival in univariate analyses, including stage of disease, type of tumor (borderline or malignant), and optimal debulking. CONCLUSION: Loss of ER beta expression in ovarian tumors may be a feature of malignant transformation. Determining ER subtypes expression may improve response to hormonal therapy by tailoring the use of selective estrogen receptor modulators with different ER affinity in selected women. As a prognostic indicator, ER beta levels may be useful in deciding the need for and choice of adjuvant treatment in women with early ovarian cancers.