The aim of the present study was to investigate the expression of estrogen receptor β (ERβ) in triple-negative and triple-positive breast cancer patients, and evaluate its utility as a prognostic factor. Between January 2000 and December 2010, primary tumor tissue samples were collected from 234 subjects, including 107 triple-negative and 127 triple-positive breast cancer patients. The samples were embedded in paraffin and immunohistochemical staining was conducted to determine the expression levels of ERβ. The Kaplan-Meier method was used to analyze patient survival rates. ERβ expression was observed in 38/107 patients (35.5%) with triple-negative breast cancer and 63/127 patients (49.6%) with triple-positive breast cancer. The ERβ expression rate was significantly decreased in the patients with triple-negative breast cancer, as compared with those with triple-positive breast cancer (P=0.03). Analysis of the survival rates indicated that patients with triple-negative breast cancer and positive ERβ expression exhibited poor disease progression-free survival (DFS) compared with those with negative ERβ expression (P=0.021). However, no statistically significant difference was observed in the DFS between the triple-positive breast cancer patients with positive and negative ERβ expression. Therefore, the expression of ERβ varies between triple-negative and triple-positive breast cancer patients. In addition, positive expression of ERβ indicates a poor prognosis in triple-negative breast cancer patients; however, this is not the case for triple-positive breast cancer patients.

The aim of the present study was to investigate the association between the expression levels of estrogen receptor (ER)β and the curative effect of endocrine therapy in breast cancer patients. Cancer tissues were collected from 583 breast cancer patients between January 2000 and December 2010 and used for analysis. ERβ expression levels were determined using immunohistochemical staining. The Kaplan-Meier method was used for survival analysis and the log-rank test was conducted for difference analysis between survival times. In addition, Cox multivariate analysis was performed to analyze prognostic factors for breast cancer. In the immunohistochemical staining assay, a positive ERβ expression rate of <10% was defined as ERβ low expression, while >10% was defined as ERβ high expression. In patients expressing low levels of ERβ, the median tumor-free survival time of the patients who received endocrine therapy was significantly higher compared with that of the patients who did not receive endocrine therapy. By contrast, in patients with high ERβ expression levels, there was no significant difference in the median tumor-free survival time between the patients who received endocrine therapy and those who did not. In addition, compared with ERβ low expression patients, ERβ high expression patients had a significantly lower median tumor-free survival time. Furthermore, ERβ expression, human epidermal growth factor receptor 2 expression, tumor size, lymph node metastasis, postoperative chemotherapy, radiotherapy and endocrine therapy were identified to be independent prognostic factors for breast cancer. Therefore, high ERβ expression in breast cancer indicates poor prognosis for endocrine therapy.

PurposeThis study is to investigate the estrogen receptor β (ERβ) expression in molecular subtypes of breast cancer and clinic significance of ERβ expression.MethodThe ERβ expression was detected in 730 cases of breast cancer tissue specimens by immunohistochemistry. Twenty-one patients were censored during 2–10 years follow-up. The difference in ERβ expression was analyzed by Pearson Chi-square Test. Its correlation with estrogen receptor α (ERα), progesterone receptor (PR) and human epidermal growth factor receptor 2 (Her-2) was analyzed by Spearman rank correlation. The accumulative tumor-free survival rate was calculated by Kaplan-Meier method and difference in survival rate was analyzed by Log-rank test. Cox regression was used for multi-factor analysis.ResultThe ERβ expression was significantly different among the molecular subtypes of breast cancer (P < 0.05). The ERβ expression in breast cancer was positively correlated with Her-2 (P < 0.05) while it had no correlation with ERα and Her-2. The expression of ERα was negatively correlated with Her-2 (P < 0.01) whereas positively correlated with PR (P < 0.01). The expression of PR was negatively correlated with Her-2 (P < 0.05). The tumor-free survival rate in patients with positive ERβ expression was significantly lower than that in patients with negative ERβ expression.ConclusionPositive ERβ expression is a poor prognostic factor of breast cancer.Virtual slidesThe virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1084557586106833

Abstract. The aim of the present study was to investigate the role of estrogen receptor (ER) β in the prognosis of ERα-positive breast cancer in postmenopausal women, and its effect on the efficacy of endocrine therapy. Tissue specimens from 195 patients with postmenopausal breast cancer were analyzed. ERβ expression levels were detected using immunohistochemical staining. Kaplan-Meier analysis was performed to assess patient survival, and the difference in survival was analyzed using the log-rank test. Cox regression was utilized to evaluate prognostic factors. The results revealed that the disease-free survival rate decreased dramatically as ERβ expression levels increased in all postmenopausal ERα-positive breast cancer patients, and ERβ expression was identified to be an indicator of poor prognosis in cases of this disease. Similarly, in postmenopausal ERα-positive breast cancer patients undergoing endocrine therapy, high ERβ expression levels reduced the disease-free survival rate and were correlated with poor patient prognosis. However, in such patients who were not treated with endocrine therapy, disease-free survival rate and prognosis were not significantly affected by ERβ expression. In conclusion, ERβ overexpression led to endocrine therapy resistance and poor prognosis in postmenopausal ERα-positive breast cancer patients, suggesting that ERβ may affect breast cancer prognosis via an increase in endocrine therapy resistance.

β-catenin, cyclin D1 and estrogen receptor (ER)-β are closely associated with the pathogenesis of breast cancer. In the present study, tissue samples were collected from 226 patients with breast cancer. Subsequently, immunohistochemical analysis was performed to detect the expression of β-catenin, cyclin D1 and ER-β, and the Kaplan-Meier method was used for survival analysis. The abnormal expression rate of β-catenin was 75.2%, while the cyclin D1 positive expression rate was 77.0% and the ER-β positive expression rate was 43.4%. In the tissue samples exhibiting abnormal expression of β-catenin, the positive expression rate of cyclin D1 (85.9%) was significantly higher compared with the samples that expressed β-catenin normally (50.0%). Furthermore, the positive expression rate of ER-β (35.7%) in the β-catenin normal expression tissues was significantly lower compared with that in the β-catenin abnormal expression tissues (45.9%). In the tissues with positive cyclin D1 expression, the positive expression rate of ER-β (48.4%) was significantly higher compared with the cyclin D1 negative expression samples (26.9%). In addition, patients with normal expression of β-catenin and positive expression of cyclin D1 exhibited longer tumor-free survival times. Therefore, an association exists among the abnormal expression of β-catenin and the positive expression of cyclin D1 and ER-β, which may contribute to the development of breast cancer.