Expressions of drug-resistant proteins in breast cancer and their relationship with the status of ER,PR

Objective To study the expressions and the significance of HER-2, MGMT , GST-π, P-gp, TopⅡ in breast cancer and find their relationship with the status of ER,PR. Methods Use S-P immunohistochemical method to examine the expressions of ER ,PR ,HER-2 ,MGMT , GST-π,P-gp and TopⅡ. 10 cases of benign breast lesions and 10 specimens of paracancer tissue were taken as control. Results In 52 specimens, HER-2,MGMT,GST-π,P-gp and TopⅡ expressed weakly in benign lesion. In cancer tissue, the expression rates of them were, 36.5%,61.5%,44.2%,38.5% and 51.9% respectively, which were higher than those in paracancei tissue. HER-2 expression was related to the original diameter of the tumor and lymph node metastasis(P<0.05), and was negatively correlated to ER, PR levels(r=-0.67,P<0.05);GST-π expression was related to lymph node histological grade, however, it was negatively correlated to ER, PR levels(r=-0.36,P<0.05);P-gp correlated with lymph node metastasis and histological grade of the tumor, the difference had significant tumor size and grade(P<0.05). There were no significant differences of MGMT expression in age, tumor size, histological grade in the treatment group, and the MGMT expression had no relation to the ER, PR status. Conclusions Combined detection of HER-2, MGMT, GST-π, P-gp, TopⅡ, ER and PR can be a guide for the treatment of breast cancer and is also an important indicator of prognosis. Key words: Breast cancer; ER; PR; HER-2; MGMT; GST-π; P-gp; TopⅡ