Abstract
摘要
Clinical significance of HER2‑low expression in non-metastatic breast cancer: a nationwide study from the Taiwan Cancer Registry
非轉移性乳癌中 HER2 低表達的臨床意義：一項來自台灣癌症資料庫的全國性研究
Hsin-Ya Huang, M.S.1,2 Dar-Ren Chen, M.D.1 Li-Na Liao, Ph.D.2
Hsin-Ya Huang, M.S. 1 ,2 陳達人, M.D. 1 廖麗娜, Ph.D. 2
1Division of Breast Surgery, Department of Surgery, Changhua Christian Hospital, Changhua, Taiwan 2Department of Public Health, College of Public Health, China Medical University, Taichung, Taiwan
1 彰化基督教醫院外科學系乳腺外科，彰化，台灣 2 中國醫藥大學公共衛生學院公共衛生學系，台中，台灣
Purpose
目的
The recent identification of HER2-low breast cancer as a distinct subtype has raised questions about its clinical significance compared to HER2-zero tumors. This study aimed to investigate the clinicopathological characteristics and survival outcomes between HER2-low and HER2-zero breast cancer patients using nationwide Taiwan database.
最近，HER2-low 乳癌被認定為一種獨特的亞型，這引起了人們對其與 HER2-0 腫瘤相比的臨床意義的疑問。本研究利用全國性的台灣資料庫，探討 HER2-低型與 HER2-零型乳癌患者的臨床病理特徵與存活率。
Materials and Methods
材料與方法
Women with newly diagnosed stage I to III breast cancers from January 2011 to December 2019 were identified from the Taiwan Cancer Registry. Patients were categorized as HER2-low (IHC 1+ or 2+/ISH-negative) or HER2-zero (IHC 0). The main outcome measurements of our study were overall survival (OS), disease-free survival (DFS) and breast cancer-specific survival (BCSS) which were compared between the HER2-low and HER2-zero groups stratified by hormone receptor (HR) status. Kaplan-Meier analysis and Cox proportional hazards models were used for survival analysis.
2011 年 1 月至 2019 年 12 月新診斷為 I 至 III 期乳癌的婦女均來自台灣癌症資料庫。患者被分類為 HER2 低 (IHC 1+ 或 2+/ISH 陰性) 或 HER2 零 (IHC 0)。本研究的主要結果測量為總生存期 (OS)、無病生存期 (DFS) 及乳癌特異性生存期 (BCSS)，並以荷爾蒙受體 (HR) 狀態分層，比較 HER2 低組與 HER2 零組。存活率分析採用 Kaplan-Meier 分析和 Cox 比例危害模型。
Results
結果
Among 53,386 patients, 36,349 (68.1%) had HER2-low and 17,037 (31.9%) had HER2-zero breast cancer. Median follow-up of the cohort was 52.17 months. HER2-low patients demonstrated distinct clinicopathological characteristics, including younger age in hormone receptor (HR)-positive cases but older age in HR-negative cases, higher rates of ductal histology, and more advanced pathological staging. Overall survival rates were 92.41% vs 93.15% (p=0.1687), BCSS rates were 94.32% vs 94.88% (p=0.2888), and DFS rates were 90.28% vs 91.47% (p=0.5774) for HER2-low vs HER2-zero groups, respectively. In HR-positive patients, HER2-zero showed superior DFS compared to HER2-low (93.17% vs 91.48%, p = 0.009), but this difference disappeared in multivariate analysis (HR: 1.03, 95% CI: 0.96-1.11, p = 0.365).
在 53,386 位病患中，36,349 位 (68.1%) 患有 HER2 低的乳癌，17,037 位 (31.9%) 患有 HER2 零的乳癌。群組的中位隨訪時間為 52.17 個月。HER2 低患者顯示出獨特的臨床病理學特徵，包括荷爾蒙受體 (HR) 陽性病例的年齡較小，但 HR 陰性病例的年齡較大、較高的導管組織學比率，以及較晚期的病理分期。HER2 低組與 HER2 零組的總生存率分別為 92.41% vs 93.15% (p=0.1687)、BCSS 率為 94.32% vs 94.88% (p=0.2888)、DFS 率為 90.28% vs 91.47% (p=0.5774)。在 HR 陽性病患中，HER2-零組的 DFS 比 HER2-低組優異 (93.17% vs 91.48%，p=0.009)，但此差異在多元分析中消失 (HR：1.03，95% CI：0.96-1.11，p=0.365)。
Conclusion
總結
Our findings demonstrate that although HER2-low breast cancers display distinctive clinicopathological characteristics, HER2-low expression status does not constitute an independent prognostic factor in non-metastatic breast cancer patients.
我們的研究結果顯示，雖然 HER2 低度乳癌顯示出獨特的臨床病理學特徵，但 HER2 低度表達狀態並不構成非轉移性乳癌患者的獨立預後因素。