Expression characteristics and detection value of Ki67, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER-2) in patients with breast cancer

Objective: To investigate the expression characteristics of Ki-67, estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2) in breast cancer (BC) patients and to evaluate their associations with lymph node metastasis and clinical disease stage. Methodology: The clinicopathological data of 122 patients with BC admitted to Affiliated Nantong Hospital 3rd of Nantong University from April 2020 to November 2023 were analyzed retrospectively. The immunohistochemical expression of Ki67, ER, PR (labeling indices, %) and HER-2 (IHC score, 0–3+) was compared between groups stratified by lymph node metastasis status and clinical disease stage, and correlations were assessed using Spearman rank analysis. Results: Patients with lymph node metastasis had a significantly higher Ki67 labeling index and significantly lower ER and PR labeling indices than those without lymph node metastasis (all P0.05). Across clinical stages, the Ki67 labeling index increased progressively from Stage I to Stage IV, whereas ER and PR labeling indices decreased correspondingly, with all pairwise comparisons between adjacent stages remaining statistically significant (P