Department of Pathology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Unit 085, G1.3617B, Houston, TX, 77030, USA.
Department of Pathology, University of Colorado, Denver, CO, USA.
Breast Cancer Res Treat. 2021 May;187(1):95-104. doi: 10.1007/s10549-021-06208-5. Epub 2021 Apr 3.
HER2 overexpression and gene amplification are routinely tested by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), respectively. In addition, HER2 mRNA expression is also tested by the Oncotype DX assay. Discordance between laboratories among the different assays remains a problem. To improve the routine HER2 reporting, the American Society of Clinical Oncology (ASCO) and the College of American Pathologists (CAP) updated their guidelines in 2018. Our study will compare concordance of HER2 status by IHC and FISH using ASCO/CAP 2013 and 2018 guidelines with Oncotype DX.
We retrospectively reviewed 657 estrogen receptor positive primary breast cancer cases with available Oncotype DX tests between 2011 and 2018. Medical records were reviewed for HER2 results by IHC, FISH, and Oncotype DX. The HER2 results by different assays and between 2013 and 2018 guidelines were compared.
Of the 657 cases, 280 were tested by IHC, FISH, and Oncotype DX. HER2-equivocal cases by IHC 2013 guidelines were all negative (67/67, 100%) by FISH 2018 guidelines and by Oncotype DX. HER2-equivocal cases by FISH 2013 guidelines were all negative (16/16, 100%) by FISH 2018 guidelines, while 15/16 (93.8%) negative and 1/16 (6.2%) equivocal by Oncotype DX. The HER2-equivocal and HER2-negative groups were similar in age, gender, histology, grade, and Ki67 score.
HER2 concordance was highest between Oncotype DX (99.6%) and FISH per 2018 guidelines. This suggests that the ASCO/CAP 2018 guidelines improved the accurate stratification of HER2-equivocal cases.
HER2 过表达和基因扩增分别通过免疫组织化学（IHC）和荧光原位杂交（FISH）进行常规检测。此外，还通过 Oncotype DX 检测 HER2 mRNA 表达。不同检测方法之间实验室之间的不一致仍然是一个问题。为了改进常规 HER2 报告，美国临床肿瘤学会（ASCO）和美国病理学家协会（CAP）于 2018 年更新了他们的指南。我们的研究将使用 ASCO/CAP 2013 和 2018 指南和 Oncotype DX 比较 IHC 和 FISH 检测的 HER2 状态的一致性。
我们回顾性分析了 2011 年至 2018 年间 657 例雌激素受体阳性原发性乳腺癌患者的 Oncotype DX 检测结果。对 HER2 检测的 IHC、FISH 和 Oncotype DX 结果进行了回顾性分析。比较了不同检测方法和 2013 年至 2018 年指南之间的 HER2 检测结果。
在 657 例病例中，有 280 例同时进行了 IHC、FISH 和 Oncotype DX 检测。IHC 2013 指南的 HER2 不确定病例，FISH 2018 指南均为阴性（67/67，100%），Oncotype DX 也为阴性。FISH 2013 指南的 HER2 不确定病例，FISH 2018 指南均为阴性（16/16，100%），而 Oncotype DX 为阴性 15/16（93.8%），不确定 1/16（6.2%）。HER2 不确定和 HER2 阴性组在年龄、性别、组织学、分级和 Ki67 评分方面相似。
Oncotype DX（99.6%）与 FISH 2018 指南之间的 HER2 一致性最高。这表明 ASCO/CAP 2018 指南提高了 HER2 不确定病例的准确分层。
