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 3 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 <0.05), whereas HER-2 IHC scores did not differ significantly between the two groups (>0.05). 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 (<0.05). Spearman analysis showed that the Ki67 labeling index was positively correlated with lymph node metastasis and clinical disease stage, whereas ER and PR labeling indices were negatively correlated with both parameters (<0.05). In contrast, HER-2 IHC score showed no significant correlation with lymph node status or clinical stage (>0.05).

[CONCLUSIONS] BC patients exhibit characteristic alterations in Ki67, ER, and PR immunohistochemical expression, and the degree of Ki67 increase together with ER and PR decrease is closely associated with lymph node metastasis and clinical disease stage. These findings suggest that combined assessment of these biomarkers may be useful for risk stratification and staging in breast cancer.