Breast cancer (BC) is a heterogeneous disease with evolving genetic alterations and expressions of receptor proteins. Intratumoral heterogeneity (ITH) is considered to be a resistance factor in response to targeted therapies. The current single-slide, single-marker immunohistochemistry techniques cannot accurately assess ITH at the individual cancer cell level. In this study, we develop a novel brightfield multiplex assay to simultaneously assess estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) protein markers, together with the HER2 gene and the centromere of chromosome 17 (CEP17) copy numbers, using a single tissue section. The data presented herein demonstrate heterogeneous cancer cell subpopulations in 11 HER2-positive/ER-positive (HER2+/ER+) tumors among 33 BCs analyzed immunohistochemically (HER2 score of 2+ or 3+). The predominant cancer cell subpopulation was HER2+/ER- (50.18%), followed by HER2+/ER+ (39.05%), HER2-/ER+ (4.26%), ER- with HER2 microheterogeneity cancer cells (3.58%), and ER+ with HER2 microheterogeneity cancer cells (2.93%). The three other tumor subtypes, namely, HER2-/ER+, HER2+/ER-, and HER2-/ER-, were more homogeneous, representing 82.59%, 99.22%, and 100% of cancer cells, respectively. This novel assay revealed that HER2+ cancer cells were more predominant than ER+ cancer cells in HER2+/ER+ tumors and provided new insights toward our understanding of BC carcinogenesis.

中文翻译：

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肿瘤内雌激素受体在人类表皮生长因子受体2-阳性乳腺癌中表达的异质性，通过明视野多重分析评估。

乳腺癌（BC）是一种异质性疾病，具有不断发展的遗传改变和受体蛋白表达。肿瘤内异质性（ITH）被认为是针对靶向治疗的耐药因素。当前的单幻灯片，单标记免疫组织化学技术无法在单个癌细胞水平上准确评估ITH。在这项研究中，我们开发了一种新颖的明场多重分析技术，可同时评估雌激素受体（ER）和人类表皮生长因子受体2（HER2）蛋白标记，以及HER2基因和17号染色​​体着丝粒（CEP17）的拷贝数，单个组织切片。本文提供的数据证明了免疫组织化学方法分析的33 BC中11种HER2阳性/ ER阳性（HER2 + / ER +）肿瘤中的异种癌细胞亚群（HER2评分为2+或3+）。癌细胞亚群为HER2 + / ER-（50.18％），其次为HER2 + / ER +（39.05％），HER2- / ER +（4.26％），带有HER2微异质性癌细胞的ER-（3.58％）和带有HER2的ER +微异质性癌细胞（2.93％）。其他三种肿瘤亚型，即HER2- / ER +，HER2 + / ER-和HER2- / ER-更均一，分别代表癌细胞的82.59％，99.22％和100％。这项新颖的检测方法揭示了在HER2 + / ER +肿瘤中HER2 +癌细胞比ER +癌细胞更占优势，并为我们对BC癌变的理解提供了新的见解。HER2- / ER +，HER2 + / ER-和HER2- / ER-更均一，分别代表癌细胞的82.59％，99.22％和100％。这项新颖的检测方法揭示了在HER2 + / ER +肿瘤中HER2 +癌细胞比ER +癌细胞更占优势，并为我们对BC癌变的理解提供了新的见解。HER2- / ER +，HER2 + / ER-和HER2- / ER-更均一，分别代表癌细胞的82.59％，99.22％和100％。这项新颖的检测方法揭示了在HER2 + / ER +肿瘤中HER2 +癌细胞比ER +癌细胞更占优势，并为我们对BC癌变的理解提供了新的见解。