Estrogen and progesterone receptor status and outcome in epithelial ovarian cancers and low malignant potential tumors

Objective: Receptors for estrogen (ER) and progesterone (PR) are prognostic indicators for a variety of endocrine tumors including breast and endometrial. This study was conducted to determine if ER and PR expression patterns are predictive of outcome in patients with epithelial ovarian cancer (EOC) or ovarian low malignant potential (LMP) tumors. Methods: ER and PR protein levels were assessed by immunohistochemistry in 45 LMP and 89 EOC samples. Patterns of ER/PR expression (individually and combinations of ER-/PR-, ER+/PR-, ER-/PR+, and ER+/PR+) were correlated with standard prognostic factors of overall survival (OS) in this patient population. Results: For patients with EOC, the 5-year OS per ER-/PR+, ER+/PR-, ER+/PR+, and ER-/PR- expression was 83%, 79%, 61%, and 48%, respectively, and these differences were statistically significant. In multivariate analyses, ER/PR expression patterns were found to be independent predictors of OS, as were the classical prognostic factors of grade, stage, debulking, and chemotherapy response to treatment. In patients with mucinous LMP tumors, ER and PR were absent. Because no LMP patients died of disease during the studied period, no correlation analysis with OS could be performed. Conclusions: Patterns of ER/PR expression provide prognostic information in EOC. Additional studies evaluating hormonal inhibition may help personalize the therapy of patients with ovarian cancer.