Breast cancer is a prevalent malignancy with increasing incidence, particularly in Asian countries. Classification based on estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status is pivotal in determining treatment. Recent advances have challenged the traditional dichotomy in HER2 classification, prompting investigation into the HER2-low subtype’s characteristics and outcomes. This retrospective study analyzed 10,186 non-metastatic hormone receptor (HR)-positive, HER2-negative breast cancer cases treated from 2008 to 2020. Data encompassed clinical, pathological, and treatment information. Oncologic outcomes included disease-free survival (DFS), overall survival (OS), and breast cancer-specific survival (BCSS). In total, 56.5% were HER2-low cases. Differences in patient characteristics were noted, with moreBRCA1/2mutations and higher mastectomy rates in the HER2-low group (p= 0.002,p< 0.001, respectively). Fewer received adjuvant chemotherapy or radiation therapy, and fewer histologic and nuclear grade 1 tumors were identified (allp< 0.001). With a median follow-up of 64 months (range: 13–174), HER2-low cases exhibited better DFS, OS, and BCSS than HER2-0 cases (p= 0.012,p= 0.013, andp= 0.013, respectively). Notably, the prognosis differed between premenopausal and postmenopausal subgroups, with BCSS benefitting premenopausal patients (p= 0.047) and DFS and OS benefitting postmenopausal patients in the HER2-low group (p= 0.004,p= 0.009, respectively). Multivariate analysis confirmed HER2 status as an independent predictor of these outcomes (p= 0.010,p= 0.008, andp= 0.014, respectively). This extensive single-center study elucidates the favorable prognosis associated with HER2-low status in HR-positive breast cancer. However, this effect differs among premenopausal and postmenopausal patients, necessitating further research into the underlying tumor biology.
乳腺癌是一种发病率不断上升的常见恶性肿瘤，在亚洲国家尤为显著。基于雌激素受体（ER）、孕激素受体（PR）和人表皮生长因子受体2（HER2）状态的分类对治疗方案制定至关重要。近期研究进展对HER2分类的传统二分法提出了挑战，促使学界对HER2低表达亚型的特征及预后展开研究。本回顾性研究分析了2008年至2020年间治疗的10,186例非转移性激素受体（HR）阳性、HER2阴性乳腺癌病例，数据涵盖临床、病理及治疗信息。肿瘤学结局包括无病生存期（DFS）、总生存期（OS）和乳腺癌特异性生存期（BCSS）。总体病例中56.5%为HER2低表达型。患者特征存在差异：HER2低表达组携带更多BRCA1/2基因突变且乳房切除术实施率更高（p值分别为0.002和<0.001）。该组接受辅助化疗或放疗者较少，组织学及核分级1级肿瘤占比更低（所有p值均<0.001）。中位随访64个月（范围13-174个月）显示，HER2低表达病例的DFS、OS和BCSS均优于HER2零表达病例（p值分别为0.012、0.013和0.013）。值得注意的是，绝经前与绝经后亚组的预后存在差异：在HER2低表达组中，BCSS优势体现在绝经前患者（p=0.047），而DFS与OS优势则见于绝经后患者（p值分别为0.004和0.009）。多变量分析证实HER2状态是这些结局的独立预测因子（p值分别为0.010、0.008和0.014）。这项大规模单中心研究阐明了HR阳性乳腺癌中HER2低表达状态与良好预后的相关性，但该效应在绝经前与绝经后患者中存在差异，需进一步探究其潜在的肿瘤生物学机制。
The Impact of HER2-Low Expression on Oncologic Outcomes in Hormone Receptor-Positive Breast Cancer
肿瘤(癌症)患者之家