Prognostic significance of Ki67 in Chinese women diagnosed with ER + /HER2 − breast cancers by the 2015 St. Gallen consensus classification

Background This study evaluated the distribution pattern of the Ki67-labeling index (LI) among patients at a Chinese breast cancer center, and analyzed its prognostic significance in the 2015 St Gallen consensus breast cancer classification, estrogen receptor-positive and human epidermal growth factor receptor 2-negative(ER+/HER2−)subtype.