Department of Clinical Pathology, University Clinical Centre of the Republic of Srpska, Banja Luka, Bosnia and Herzegovina.
Bosn J Basic Med Sci. 2019 Aug 20;19(3):242-248. doi: 10.17305/bjbms.2019.3970.
Determination of human epidermal growth factor receptor 2 (HER2) status is important for adequate treatment of breast cancer (BC) patients. The novel HER2 gene protein assay (GPA) is particularly convenient, as it allows the simultaneous assessment of HER2 protein expression and gene amplification at individual cell level. Here we investigated the frequency of internodal HER2 heterogeneity in axillary lymph node macrometastases of BC patients and compared HER2 status between primary breast tumor and its metastases. We included a total of 41 female patients operated between 2014 and 2015 for primary BC with axillary lymph node macrometastases. Representative paraffin blocks of metastatic lymph nodes were sectioned and the slides were stained using the GPA in 38 BC cases. GPA results were assessed according to the ASCO/CAP 2013 criteria. We analyzed 12586 individual tumor cells, 120 cells per section of each metastatic lymph node. HER2 status differed between the primary tumor and its metastases in 5/38 cases (13.2%). In patients with at least two metastatic nodes, the HER2 status of lymph node metastases was only slightly different in 4/23 cases (17.4%). Our results indicate rare but substantial differences in HER2 status between primary breast tumor and its axillary lymph node metastases that may direct the choice and outcomes of targeted therapy in BC patients. The impact of the rare and subtle internodal HER2 heterogeneity evidenced in this study remains uncertain. Determining the HER2 status of lymph node metastases in BC seems to be rational, but assessing a limited number of metastatic nodes may be sufficient.
确定人表皮生长因子受体 2（HER2）状态对于乳腺癌（BC）患者的充分治疗非常重要。新型 HER2 基因蛋白检测（GPA）特别方便，因为它允许在单个细胞水平上同时评估 HER2 蛋白表达和基因扩增。在这里，我们研究了 BC 患者腋窝淋巴结大转移中节内 HER2 异质性的频率，并比较了原发性乳腺癌及其转移之间的 HER2 状态。我们共纳入了 41 名女性患者，她们在 2014 年至 2015 年间因原发性 BC 伴腋窝淋巴结大转移而接受了手术。对转移性淋巴结的代表性石蜡块进行切片，并在 38 例 BC 病例中使用 GPA 进行染色。根据 ASCO/CAP 2013 标准评估 GPA 结果。我们分析了 12586 个肿瘤细胞，每个转移性淋巴结切片 120 个细胞。HER2 状态在 5/38 例（13.2%）原发性肿瘤与其转移之间存在差异。在至少有两个转移性淋巴结的患者中，4/23 例（17.4%）淋巴结转移的 HER2 状态仅略有不同。我们的结果表明，原发性乳腺癌与其腋窝淋巴结转移之间的 HER2 状态存在罕见但实质性差异，这可能会指导 BC 患者靶向治疗的选择和结果。本研究中证实的罕见且细微的节内 HER2 异质性的影响仍不确定。确定 BC 中淋巴结转移的 HER2 状态似乎是合理的，但评估有限数量的转移性淋巴结可能就足够了。
