Department of Pathology, BML 116, Yale University School of Medicine, 310 Cedar St, PO Box 208023, New Haven, CT, USA.
J Clin Oncol. 2011 Aug 1;29(22):2978-84. doi: 10.1200/JCO.2010.32.9706. Epub 2011 Jun 27.
Recent misclassification (false negative) incidents have raised awareness concerning limitations of immunohistochemistry (IHC) in assessment of estrogen receptor (ER) in breast cancer. Here we define a new method for standardization of ER measurement and then examine both change in percentage and threshold of intensity (immunoreactivity) to assess sources for test discordance.
An assay was developed to quantify ER by using a control tissue microarray (TMA) and a series of cell lines in which ER immunoreactivity was analyzed by quantitative immunoblotting in parallel with the automated quantitative analysis (AQUA) method of quantitative immunofluorescence (QIF). The assay was used to assess the ER protein expression threshold in two independent retrospective cohorts from Yale and was compared with traditional methods.
Two methods of analysis showed that change in percentage of positive cells from 10% to 1% did not significantly affect the overall number of ER-positive patients. The standardized assay for ER on two Yale TMA cohorts showed that 67.9% and 82.5% of the patients were above the 2-pg/μg immunoreactivity threshold. We found 9.1% and 19.7% of the patients to be QIF-positive/IHC-negative, and 4.0% and 0.4% to be QIF-negative/IHC-positive for a total of 13.1% and 20.1% discrepant cases when compared with pathologists' judgment of threshold. Assessment of survival for both cohorts showed that patients who were QIF-positive/pathologist-negative had outcomes similar to those of patients who had positive results for both assays.
Assessment of intensity threshold by using a quantitative, standardized assay on two independent cohorts suggests discordance in the 10% to 20% range with current IHC methods, in which patients with discrepant results have prognostic outcomes similar to ER-positive patients with concordant results.
最近的错误分类（假阴性）事件引起了人们对免疫组织化学（IHC）在乳腺癌雌激素受体（ER）评估中的局限性的认识。在这里，我们定义了一种新的 ER 测量标准化方法，然后检查百分比和强度（免疫反应性）的阈值变化，以评估测试不一致的原因。
开发了一种通过使用对照组织微阵列（TMA）和一系列细胞系来定量 ER 的测定方法，其中通过定量免疫印迹平行分析 ER 免疫反应性，并使用定量免疫荧光（QIF）的自动定量分析（AQUA）方法进行分析。该测定方法用于评估耶鲁大学的两个独立回顾性队列中的 ER 蛋白表达阈值，并与传统方法进行了比较。
两种分析方法表明，阳性细胞百分比从 10%降至 1%并不会显著影响 ER 阳性患者的总数。在两个耶鲁 TMA 队列的标准化 ER 测定中，67.9%和 82.5%的患者的免疫反应性高于 2pg/μg 阈值。我们发现 9.1%和 19.7%的患者为 QIF 阳性/IHC 阴性，4.0%和 0.4%的患者为 QIF 阴性/IHC 阳性，总共有 13.1%和 20.1%的病例与病理学家判断的阈值不一致。对两个队列的生存评估表明，QIF 阳性/病理学家阴性的患者的结果与两种检测均为阳性的患者的结果相似。
在两个独立的队列中使用定量、标准化的测定方法评估强度阈值表明，与当前的 IHC 方法相比，在 10%至 20%范围内存在不一致，其中具有不一致结果的患者的预后结果与具有一致结果的 ER 阳性患者相似。
