Douganiotis George, Kontovinis Loukas, Markopoulou Efrosini, Ainali Alexandra, Zarampoukas Thomas, Natsiopoulos Ioannis, Papazisis Konstantinos
3rd Department of Medical Oncology, Theagenio Cancer Hospital, Thessaloniki, Greece.
Medical Oncology Department, Euromedica General Clinic, Thessaloniki, Greece.
Cancer Diagn Progn. 2022 May 3;2(3):316-323. doi: 10.21873/cdp.10111. eCollection 2022 May-Jun.
BACKGROUND/AIM: A possible role of antibody-drug conjugates against tumors with low HER2-expression, leads to the emergence of a new "low-HER2" classification in breast cancer, encompassing tumors from the hormonal-receptor-positive and the triple-negative subgroups. There is a need for data (clinical trial data and real-world evidence) that will accurately describe this population, the risk of recurrence and the possible benefit of HER2 targeted therapies.
We retrospectively analyzed 949 patients from our Department databases, with hormonal receptor-positive and HER2-negative early breast cancer, for whom detailed data for immunohistochemical HER2-staining could be retrieved.
HER2-low expression was detected in 66.6% of patients (472 IHC +1 and 160 IHC +2 and ISH-negative). Lobular, or mixed lobular and ductal cancers had a statistically significantly lower chance of being HER2-low when compared to pure infiltrative ductal carcinomas (53.1% vs. 69.3% respectively). HER2-low status was not prognostic for recurrence-free survival or response to neoadjuvant chemotherapy. There was a non-significant trend for increased risk of recurrence for HER2-low, compared to HER2-0, in patients with lobular or mixed lobular and ductal carcinomas (HR=2.192, 95% CI=0.819-5.912).
Low expression of HER2 in hormonal receptor-positive early breast cancer does not affect prognosis but may lead to a shorter progression-free-survival in lobular and mixed ductal and lobular cancers. Despite optimal management, a large proportion of hormonal receptor-positive patients will relapse. Targeting HER2 in HER2-low cancers may offer a potential additional treatment strategy to improve survival of this group.
背景/目的：抗体药物偶联物对低HER2表达肿瘤可能具有的作用，促使乳腺癌中出现了一种新的“低HER2”分类，涵盖激素受体阳性和三阴性亚组的肿瘤。需要数据（临床试验数据和真实世界证据）来准确描述这一人群、复发风险以及HER2靶向治疗可能带来的益处。
我们回顾性分析了来自本部门数据库的949例激素受体阳性且HER2阴性的早期乳腺癌患者，这些患者的免疫组化HER2染色详细数据可被获取。
66.6%的患者检测到HER2低表达（472例免疫组化+1和160例免疫组化+2且原位杂交阴性）。与单纯浸润性导管癌相比，小叶癌或小叶与导管混合癌HER2低表达的几率在统计学上显著更低（分别为53.1%和69.3%）。HER2低状态对无复发生存期或新辅助化疗反应无预后意义。在小叶癌或小叶与导管混合癌患者中，与HER2为0的患者相比，HER2低表达患者复发风险有增加的非显著趋势（风险比=2.192，95%置信区间=0.819 - 5.912）。
激素受体阳性早期乳腺癌中HER2低表达不影响预后，但可能导致小叶癌及小叶与导管混合癌的无进展生存期缩短。尽管进行了最佳管理，仍有很大比例的激素受体阳性患者会复发。在HER2低表达癌症中靶向HER2可能提供一种潜在的额外治疗策略，以提高该组患者的生存率。
