New insights into HER2-low breast cancer brain metastasis: A retrospective analysis
Hangcheng Xu,
Yan Wang,
Li Li,
Yiqun Han,
Yun Wu,
Qiang Sa,
Binghe Xu,
Jiayu Wang
Affiliations
Hangcheng Xu
Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17, Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China
Yan Wang
Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17, Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China
Li Li
Department of Medical Records, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17, Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China
Yiqun Han
Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17, Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China
Yun Wu
Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17, Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China
Qiang Sa
Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17, Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China
Binghe Xu
Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17, Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China; Corresponding author.
Jiayu Wang
Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, No. 17, Panjiayuan Nanli, Chaoyang District, Beijing, 100021, China; Corresponding author.
Background: A considerable number of patients with breast cancer will suffer from brain metastasis in the advanced setting. The HER2 status serves as a significant prognostic factor and the reference of applying treatment for patients with breast cancer brain metastasis (BCBM). Methods: Between January 2010 and July 2021, patients with BCBM who had available HER2 status were identified. The patients with HER2 1+ in immunohistochemistry (IHC) or IHC 2+ and fluorescence in situ hybridization (FISH) negative were categorized as HER2-low. Comparisons were conducted between the HER2-low and HER2-zero population. The primary endpoint was overall survival (OS) after the diagnosis of BCBM. Survival outcomes were assessed using Kaplan-Meier curves with log-rank test and Cox proportional hazards model. Results: In this study, we analyzed 71 patients with the HER2-low breast cancer subtype and 64 patients with the HER2-zero subtype. Despite the limited sample size, our findings revealed a significantly better OS for patients with HER2-low cancer compared to their HER2-zero counterparts (26 m vs 20 m, p = 0.0017). This trend was particularly notable in the HR-negative group (26 m vs 13 m, p = 0.0078), whereas no significant difference was observed among the HR-positive patients. Furthermore, Cox regression analysis revealed that the HER2-low status was an independent prognostic factor for better survival in the HR-negative patients (p = 0.046 in multivariate analysis). Conclusions: Patients diagnosed with HER2-low BCBM exhibited a more favorable prognosis than those with HER2-zero BCBM, particularly within the HR-negative subgroup. The low expression of HER2 is supposed to be linked to the prolonged survival of BCBM patients.
