Effect of neoadjuvant chemotherapy on the expression of hormone receptors and Ki67 in Chinese breast cancer patients: A retrospective study of 525 patients

This study was designed to investigate the effect of neoadjuvant chemotherapy on the expression of hormone receptors and Ki67 in Chinese female breast cancer patients. The expression of estrogen receptor (ER), progesterone receptor (PR) and Ki67 among 525 neoadjuvant chemotherapy cases was studied by immunohistochemistry. Differences between specimens made through preoperative core needle biopsy and excised tissue biopsy were observed. The positive rates of ER, PR and Ki67 in core needle biopsy and excised tissue biopsy were 65.3% and 63.2%, 51.0% and 42.6%, 65.6% and 43.4%, respectively. The expression of ER, PR and Ki67 in core needle biopsy and excised tissue biopsy had no statistically significant difference. However, after neoadjuvant chemotherapy, the discordance rates of ER, PR and Ki67 were 15.2% (79/521), 26.9% (140/520) and 44.8% (225/502), respectively. The ER, PR and Ki67 status changed from positive to negative in 7.5% (39/521), 13.3% (69/520) and 21.1% (106/502) of the patients, whereas ER, PR and Ki67 status changed from negative to positive in 7.7% (40/521), 13.6% (71/520) and 23.7% (119/502) of the patients, respectively. These results showed that the status of some biomarkers changes after neoadjuvant chemotherapy and biomarker status needs to be reexamined to optimize adjuvant systemic therapy and better prognosis assessment.