Evaluation of biomarker changes after administration of various neoadjuvant chemotherapies in breast cancer.

Abstract

To assess the changes in estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67 expression in breast cancer patients after various neoadjuvant chemotherapies. Data from 138 locally advanced breast cancer patients with histological diagnoses were reviewed. Seventy patients (group 1) were given 4 cycles of 500 mg/m(2) cyclophosphamide and 50 mg/m(2) pirarubicin every 21 days. Sixty-eight patients (group 2) were given 4 cycles of 500 mg/m(2) cyclophosphamide and 75 mg/m(2) docetaxel every 21 days. The biomarker changes of the operated tumor tissues were compared with the initial core biopsies. ER, PR, HER2 and Ki-67 expression changed by 28.6%, 22.9%, 17.1% and 54.3%, respectively, after neoadjuvant chemotherapy in group 1 and 16.2%, 22.1%, 13.2% and 70.6%, respectively, after neoadjuvant chemotherapy in group 2. There were significant differences between the groups regarding ER and Ki-67 status changes, and these changes can be used to inform treatment strategies.