Department of Histopathology, School of Medicine, The University of Nottingham, and Nottingham University Hospitals NHS Trust, Nottingham, UK.
Tumor Pathology Department, Maria Sklodowska-Curie Memorial National Research Institute of Oncology, Gliwice, Poland.
Pathobiology. 2022;89(5):263-277. doi: 10.1159/000525092. Epub 2022 Jun 21.
The management of patients with breast cancer (BC) relies on the assessment of a defined set of well-established prognostic and predictive markers. Despite overlap, prognostic markers are used to assess the risk of recurrence and the likely benefit of systemic therapy, whereas predictive markers are used to determine the type of systemic therapy to be offered to an individual patient. In this review, we provide an update and present some challenges in the assessment of the main BC-specific molecular predictive markers, namely hormone receptors (oestrogen receptor [ER] and progesterone receptor [PR]), human epidermal growth factor receptor 2 (HER2), and KI67. As the main platform for assessing these markers in BC is immunohistochemistry (IHC), we address the cut-off values used to define positivity, the ER-low subgroup, the existence and significance of the ER-/PR+ phenotype, the use of PR in routine practice, and the role of hormone receptors in ductal carcinoma in situ. We discuss the newly introduced HER2-low class of BC and the clinical/biological difference between different HER2 groups (e.g., HER2 IHC score 3+ BCs vs. those with a HER2 IHC score 2+ with HER2 gene amplification). The review concludes with an update on the applications of KI67 assessment in BC and observations on the role of immune checkpoint identification in BC.
乳腺癌（BC）患者的管理依赖于对一系列既定的预后和预测标志物的评估。尽管有重叠，但预后标志物用于评估复发风险和系统治疗的可能获益，而预测标志物用于确定要向个体患者提供的系统治疗类型。在这篇综述中，我们提供了更新内容，并介绍了评估主要 BC 特异性分子预测标志物（即激素受体（雌激素受体[ER]和孕激素受体[PR]）、人表皮生长因子受体 2（HER2）和 KI67）方面的一些挑战。由于评估这些标志物的主要平台是免疫组织化学（IHC），我们解决了用于定义阳性的 cutoff 值、ER 低表达亚组、ER-/PR+表型的存在和意义、PR 在常规实践中的应用以及激素受体在导管原位癌中的作用。我们讨论了新引入的 HER2 低表达 BC 类别以及不同 HER2 组之间的临床/生物学差异（例如，HER2 IHC 评分 3+BC 与 HER2 IHC 评分 2+但 HER2 基因扩增的 BC）。综述最后更新了 KI67 在 BC 中的应用，并观察了免疫检查点鉴定在 BC 中的作用。
