The characteristics of HER2 low-expressing breast cancer: a China single-center real-world data analysis

Aim: This study examined the characteristics of HER2-low breast cancer patients in our center. Methods: Data of HER2-negative breast cancer patients were collected, and the patients were divided into HER2-low and HER2-0 groups. The differences in clinicopathological features, prognosis and treatment were compared. Results: The proportion of patients in the HER2-low group who were over 50 years old, had invasive breast cancer of no special type, histological grade 1/2, ER-positive, PR-positive and Ki67 ≤30% was higher. Patients with HER2-low status had better breast cancer-specific survival and overall survival. Additionally, HER2-low status was not associated with the effectiveness of adjuvant chemotherapy and endocrine therapy. Conclusion: HER2-low breast cancer is less aggressive than HER2-0 and may represent a distinct subtype.