Expression of ERβ, ERα and Her-2 and distribution of molecular subtypes in Uygur and Han patients with breast cancer

Abstract

The aim of the present study was to investigate the expression levels of estrogen receptor (ER) α and β and human epidermal growth factor receptor-2 (Her-2), as well as the distribution of breast cancer molecular subtypes in Uygur and Han breast cancer patients. Cancer tissues were collected and analyzed from 709 breast cancer patients enrolled between January 2000 and December 2010. The expression levels of ERα, ERβ and Her-2 were determined by immunohistochemistry. The differences in expression and molecular subtype distribution between Uygur and Han patients with breast cancer were analyzed using a Pearson's χ2 test. Statistically significant differences were observed in the expression levels of ERβ, ERα and Her-2 between the Uygur and Han patients with breast cancer (P<0.05). The expression levels of ERβ (++), ERβ (+++) and Her-2 (+++) in Uygur patients were significantly higher, while the expression levels of ERα (+++) in Uygur patients were significantly lower when compared with Han patients. The percentage of luminal A type breast cancer in Uygur patients was significantly lower when compared with the Han patients, whereas the percentages of basal-like and Her-2 overexpression types were significantly higher than those in Han patients (P<0.05). Therefore, expression levels of ERβ, ERα and Her-2, and molecular subtypes of breast cancer were significantly different between the Uygur and Han populations. breast cancer (2). Estrogen receptor (ER) β, the newly identified ER subtype, has potentially important clinical value for the research of biological characteristics and prognosis evaluation of breast cancer. ERα and human epidermal growth factor receptor-2 (Her-2) are commonly used immunohistochemistry indicators in clinical practice. These receptors are important for the guidance of postoperative chemotherapy and endocrine therapy of breast cancer, as well as for the evaluation of breast cancer prognosis. Breast cancer may be divided into various molecular subtypes based on the expression levels of ERβ, progesterone receptor and Her-2. Different molecular subtypes among various ethnicities have their own characteristics (3). In the present study, the expression levels of ERβ, ERα and Her-2, as well as the distributions of various molecular subtypes, were compared between Uygur and Han patients with breast cancer in Xinjiang, China.