Department of Hematology & Oncology, Saint Joseph University, Beirut, Lebanon.
Department of Hematology & Oncology, Saint Joseph University, Beirut, Lebanon.
Ann Diagn Pathol. 2024 Oct;72:152326. doi: 10.1016/j.anndiagpath.2024.152326. Epub 2024 May 12.
Human epidermal growth factor receptor 2 (HER2)-low breast cancer has emerged as a subtype of breast cancer, defined by HER2 1+/2+ in immunohistochemistry (IHC) and absence of ERBB2 gene amplification on fluorescence in situ hybridization (FISH). Recent trials showed marked response of HER2-low breast cancer to novel anti-HER2 antibody-drug-conjugates. Data on characteristics of HER2-low breast cancer subtype is limited. Real-world data from the Anatomic Pathology Department of Hotel-Dieu de France, spanning 2017-2023, was retrospectively collected. HER2-positive patients were excluded to compare HER2-low to HER2-zero breast cancer subtypes. Clinicopathological characteristics between the groups were compared using a Chi-Squared test. Out of 1195 patients, we observed 341 (28.5 %) HER2-low breast cancers cases. HER2-positive breast cancer cases (n = 178; 14.9 %) were excluded. There was no significant difference in age and sex between HER2-low and HER2-zero group (p = 0.33 and 0.79, respectively). HER2-low breast cancer was associated with positive estrogen receptor status and positive progesterone receptor status (p < 0.001 and p = 0.01, respectively). Ductal adenocarcinomas were more commonly observed in HER2-low group (p < 0.001). When stratified by hormone (HR) status, 87.4 % of patients had HR-positive status and 12.6 % were HR-negative. Among the HR-negative group, HER2-low tumors tended to show lower proliferation index compared to HER2-zero tumors (25%vs.10 %, p = 0.04). This study showed that HER2-low is distinct from HER2-zero and is common among patients with breast cancer. Clinicopathological features such as histological type differ between HER2-zero and HER2-low breast cancer. Within HR-negative breast cancer, those with low HER2 expression exhibit a less aggressive profile compared to HER2-zero tumors.
人类表皮生长因子受体 2（HER2）低表达乳腺癌已成为乳腺癌的一种亚型，其定义为免疫组织化学（IHC）HER2 1+/2+且荧光原位杂交（FISH）无 ERBB2 基因扩增。最近的试验表明，HER2 低表达乳腺癌对新型抗 HER2 抗体药物偶联物有明显的反应。关于 HER2 低表达乳腺癌亚型特征的数据有限。本研究回顾性收集了 2017 年至 2023 年期间法国医院解剖病理学系的真实世界数据。排除 HER2 阳性患者，以比较 HER2 低表达与 HER2 零表达乳腺癌亚型。使用卡方检验比较两组间的临床病理特征。在 1195 例患者中，我们观察到 341 例（28.5%）HER2 低表达乳腺癌病例。排除 HER2 阳性乳腺癌病例（n=178；14.9%）。HER2 低表达和 HER2 零表达组在年龄和性别方面无显著差异（p=0.33 和 0.79）。HER2 低表达乳腺癌与雌激素受体阳性和孕激素受体阳性状态相关（p<0.001 和 p=0.01）。HER2 低表达组更常见的是导管腺癌（p<0.001）。按激素（HR）状态分层，87.4%的患者 HR 阳性，12.6%的患者 HR 阴性。在 HR 阴性组中，HER2 低表达肿瘤的增殖指数较 HER2 零表达肿瘤低（25%对 10%，p=0.04）。本研究表明，HER2 低表达与 HER2 零表达不同，在乳腺癌患者中较为常见。HER2 零表达和 HER2 低表达乳腺癌的临床病理特征如组织学类型不同。在 HR 阴性乳腺癌中，HER2 低表达的肿瘤与 HER2 零表达肿瘤相比，具有侵袭性较低的特征。
