Prognostic significance and clinical importance of estrogen receptor α and β in human endometrioid adenocarcinomas

Human endometrial cancer expresses both the known estrogen receptors (ER-α and ER-β). The significance of the relative expression of both ER subtypes in endometrial adenocarcinomas remains to be clarified and the usefulness of the determination of the receptor status in endometrial cancer patients is still controversially discussed. Therefore, the aims of this study were the evaluation of the expression patterns of ER-α and ER-β with the characterization of the prognostic significance in uterine endometrioid adenocarcinomas. Pathological and surgical records of 214 patients who were diagnosed with an endometrioid adenocarcinoma without other histological types (including mucinous, mixed, squamous or villoglandular differentiation) were reviewed for both estrogen receptors. The expression of both estrogen receptors was demonstrated in malignant endometrioid adenocarcinomas. ER-α was associated with histological differentiation, while ER-β demonstrated an association with ovarial invasion. The loss of receptor positivity for ER-α resulted in a poorer cause-specific survival in endometrial cancer patients, while ER-β did not affect survival. Interestingly, metastatic patients who expressed ER-α or ER-β had a better survival outcome than estrogen receptor negative patients. Moreover, when tumor samples of affected patients expressed ER-α, they had a better cause-specific survival compared to negative findings regarding both estrogen receptors. However, ER-α and ER-β were not independent factors with survival in endometrial adenocarcinoma patients. Therefore, the analysis of both estrogen receptors might be used as a marker to identify high-risk patients only in a subset of patients with endometrioid adenocarcinoma.