breast cancer

The current work obtained the approval of the Medical Ethics Committee of Zhongshan Hospital Affiliated with Dalian University. We obtained 230 pairs of postoperative pathological samples of patients undergoing breast cancer stored in paraffin wax blocks. These patients were admitted to the Department of Surgery of Zhongshan Hospital Affiliated with Dalian University between January 2014 and January 2018. All of the selected patients were naive to preoperative treatments, including neoadjuvant, radiotherapy, or chemotherapy. The selected patients had complete clinicopathological and follow-up information. All samples were subjected to freezing using liquid nitrogen (−80 °C). The present study was performed following the Declaration of Helsinki. The informed consent was acquired from all the patients.