Prognostic and metastatic implications of androgen receptor expression in HER2-negative breast cancer

This study aimed to characterize androgen receptor (AR) expression patterns negative for human epidermal growth factor receptor 2 (HER2), assess associations with clinicopathological parameters, and determine its predictive value for axillary lymph node metastasis and disease-free survival (DFS). A retrospective analysis was conducted on clinical data from 444 patients diagnosed with HER2-negative invasive breast carcinoma and treated at Bao Ding No.1 Central Hospital between January 1, 2020, and September 1, 2023. Associations between AR expressions and clinicopathological features were assessed. Logistic regression was used to identify factors associated with axillary lymph node metastasis. DFS was assessed using Kaplan–Meier analysis and Cox proportional hazards regression modeling. Positive AR expression was observed in 82.0% (364/444) of cases. Significant associations were observed between AR expression and histological grade ( p < 0.001), estrogen receptor (ER) status ( p < 0.001), progesterone receptor (PR) status ( p < 0.001), and high Ki-67 proliferation index ( p = 0.025). Subgroup analyses indicated that the relationship between AR expression and axillary lymph node metastasis was modified by ER, PR, and Ki-67 status. In PR-positive subgroups, AR positivity was associated with improved DFS and was identified as an independent protective factor (hazard ratio [HR] = 0.24, p = 0.058). AR expression exhibits subtype-specific prognostic relevance in HER2-negative breast carcinoma. Its interaction with ER, PR, and Ki-67 status may provide insights into metastatic potential and long-term outcomes. These findings support the incorporation of AR status into risk stratification models and treatment decision-making processes in HER2-negative breast cancer.