Tozbikian Gary H, Zynger Debra L
Department of Pathology, Wexner Medical Center, The Ohio State University, Columbus, OH, USA.
Breast J. 2018 Jul;24(4):535-540. doi: 10.1111/tbj.13004. Epub 2018 Mar 2.
In breast cancer, human epidermal growth factor receptor 2 (HER2) status is determined by immunohistochemistry (IHC) and/or in situ hybridization. Oncotype DX also reports HER2 status by an rt-PCR-based assay. Assay concordance between IHC and fluorescent in situ hybridization (FISH) (including alternative probe HER2 FISH) vs Oncotype DX HER2 rt-PCR has not been described in the post-2013 American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) HER2 Guideline revision setting. We performed a retrospective review of HER2 equivocal invasive breast carcinoma from 2014 to 2016 with the Oncotype DX HER2 result. Fifteen patients with HER2 equivocal invasive breast cancer had Oncotype DX performed. Of these, 13 underwent alternative probe HER2 FISH yielding 4 negative, 6 equivocal and 3 positive results. All 15 cases were classified as HER2 negative by Oncotype DX rt-PCR, including the three cases which were positive by alternative probe HER2 FISH, yielding a discordance rate for Oncotype DX rt-PCR HER2 of 20% (3/15). All three patients with HER2-positive breast cancer on the basis of alternative probe HER2 FISH received anti-HER2-targeted therapy. Treatment decisions based on HER2 status should utilize the IHC/FISH result as Oncotype DX results may incorrectly disqualify some patients from being eligible for anti-HER2 therapy based on the current 2013 ASCO/CAP HER2 Guidelines.
在乳腺癌中，人表皮生长因子受体2（HER2）状态通过免疫组织化学（IHC）和/或原位杂交来确定。Oncotype DX也通过基于逆转录聚合酶链反应（rt-PCR）的检测报告HER2状态。在2013年后美国临床肿瘤学会/美国病理学家学会（ASCO/CAP）HER2指南修订背景下，尚未描述IHC与荧光原位杂交（FISH）（包括替代探针HER2 FISH）与Oncotype DX HER2 rt-PCR之间的检测一致性。我们对2014年至2016年HER2结果不明确的浸润性乳腺癌进行了回顾性研究，并获得了Oncotype DX HER2结果。15例HER2结果不明确的浸润性乳腺癌患者接受了Oncotype DX检测。其中，13例进行了替代探针HER2 FISH检测，结果为4例阴性、6例不明确和3例阳性。所有15例病例经Oncotype DX rt-PCR检测均分类为HER2阴性，包括3例替代探针HER2 FISH检测为阳性的病例，Oncotype DX rt-PCR HER2的不一致率为20%（3/15）。所有3例基于替代探针HER2 FISH检测为HER2阳性的乳腺癌患者均接受了抗HER2靶向治疗。基于HER2状态的治疗决策应采用IHC/FISH结果，因为根据当前2013年ASCO/CAP HER2指南，Oncotype DX结果可能会错误地使一些患者失去接受抗HER2治疗的资格。
