目的:本研究旨在分析HER2超低,HER2-null,和HER2在中国乳腺癌(BC)患者中的低表达。
方法:回顾性收集1363例HER2阴性BC患者的临床病理资料(2018年1月至2019年12月)。HER2状态进一步分为HER2-null,HER2超低,HER2低。HER2无效表达被定义为完全无染色的浸润癌细胞。HER2超低表达定义为≤10%的浸润性癌细胞显示不完全和微弱/弱的膜染色。HER2低表达定义为具有阴性原位杂交(ISH)测定的HER2免疫组织化学(IHC)1+或2+。
结果:在1363名患者中,有86例(6.3%)HER2无效患者,395(29.0%)HER2超低患者,和882例(64.7%)低HER2患者。HER2超低患者在N分期方面与HER2低患者不同,激素受体(HR)状态,Ki-67表达,和手术类型。HER2超低和HER2无效患者的组织学类型和术后内分泌治疗也存在显着差异。在HER2超低患者中,HR+(81.0%)肿瘤比HR-(19.0%)肿瘤更常见。此外,HER2超低和HER2低患者的HR状态存在显著差异(P=0.001).生存分析显示,HER2状态对HER2阴性患者的无病生存期(DFS)无影响(均P>0.05)。然而,无论HER2状态如何,HR+患者的DFS优于HR-患者(P=0.003)。Cox多变量分析显示年龄(HR[95%CI]=0.950[0.928,0.972],P<0.001),HR状态(HR[95%CI]=3.342[1.658,6.736],P=0.001),和术后内分泌治疗(HR[95%CI]=0.048[0.048,0.023],P<0.001)是HER2阴性BC患者DFS的重要影响因素。
结论:HER2超低BC患者表现出明显的HER2-null和HER2-low肿瘤的临床病理特征;HER2状态(null,超低,或低)在这些HER2阴性BC人群中没有预后价值。与已发表的文献一致,HR状态是HER2阴性BC患者DFS的独立预后因素。
OBJECTIVE: This
study aims to analyze whether there are any differences in clinicopathological features and prognosis between HER2 ultra-low, HER2-null, and HER2-low expression in Chinese breast cancer (BC) patients.
METHODS: The clinicopathological data of 1363 HER2-negative BC patients were retrospectively collected (from January 2018 to December 2019). HER2 status was further classified into HER2-null, HER2 ultra-low, and HER2-low. HER2-null expression is defined as infiltrating cancer cells completely free of staining. HER2 ultra-low expression is defined as ≤10% of infiltrating cancer cells showing incomplete and faint/weak membrane staining. HER2-low expression is defined as HER2 immunohistochemistry (IHC) 1+ or 2+ with negative in situ hybridization (ISH) assay.
RESULTS: Of 1363 patients, there were 86 (6.3%) HER2-null patients, 395 (29.0%) HER2 ultra-low patients, and 882 (64.7%) HER2-low patients. HER2 ultra-low patients were different from HER2-low patients in terms of N stage, hormone receptor (HR) status, Ki-67 expression, and type of surgery. There were also significant differences in histologic type and postoperative endocrine therapy between HER2 ultra-low and HER2-null patients. HR+ (81.0%) tumors was more common than HR- (19.0%) in HER2 ultra-low patients. In addition, there was a significant difference in HR status between HER2 ultra-low and HER2-low patients (P = 0.001). The survival analysis showed that HER2 status had no effect on disease-free survival (DFS) in HER2-negative patients (all P > 0.05). However, regardless of HER2 status, HR+ patients had better DFS than HR- patients (P = 0.003). Cox multivariate analysis revealed that age (HR [95% CI] = 0.950 [0.928, 0.972], P < 0.001), HR status (HR [95% CI] = 3.342 [1.658, 6.736], P = 0.001), and postoperative endocrine therapy (HR [95% CI] = 0.048 [0.048, 0.023], P < 0.001) were important influencing factors of DFS in HER2-negative BC patients.
CONCLUSIONS: HER2 ultra-low BC patients demonstrated distinct clinicopathological features from HER2-null and HER2-low tumors; while, HER2 status (null, ultra-low, or low) had no prognostic value in these HER2-negative BC population. Consistent with the published literature, HR status was an independent prognostic factor for DFS in HER2-negative BC patients.