Changes in ER, PR and HER2 receptors status after neoadjuvant chemotherapy in breast cancer

Previous studies have reported conflicting results regarding the impact of neoadjuvant chemotherapy (NAC) on estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) status in breast cancer. Our aim was to investigate whether NAC induces some selective change in the breast biomarkers. We retrospectively detected the immunohistochemical results of ER, PR and HER2 between the core biopsy and surgical excision specimens in 113 patients with NAC. As a control group, we analyzed sample pairs from 102 patients without NAC. Fourteen (12.4%) of 113 patients undergoing NAC showed the ER status modulation in the surgically removed specimen as compared with only 4 (3.9%) of 102 women without NAC (p=0.025). Eighteen (15.9%) of 113 patients given NAC appeared in the PR status alteration in the final surgical specimen, whereas only 7 (6.9%) of 102 patients without NAC did (p=0.038). The HER2 status shift was found in 17 (15.0%) of 113 patients with NAC and in 6 (5.9%) of 102 patients without NAC, respectively (p=0.030). Neoadjuvant chemotherapy does change ER, PR and HER2 status in a statistically significant manner. Retesting these biomarkers of the residual tumor should be considered to improve future tailored adjuvant therapies.