Association among the expression of β-catenin, cyclin D1 and estrogen receptor-β in human breast cancer.

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.