Abstract：
To update ASCO-College of American Pathologists (CAP) recommendations for human epidermal growth factor receptor 2 (HER2) testing in breast cancer. The Panel is aware that a new generation of antibody-drug conjugates (ADCs) targeting the HER2 protein is active against breast cancers that lack protein overexpression or gene amplification.
An Update Panel conducted a systematic literature review to identify signals for updating recommendations.
The search identified 173 abstracts. Of five potential publications reviewed, none constituted a signal for revising existing recommendations.
The 2018 ASCO-CAP recommendations for HER2 testing are affirmed.
HER2 testing guidelines have focused on identifying HER2 protein overexpression or gene amplification in breast cancer to identify patients for therapies that disrupt HER2 signaling. This update acknowledges a new indication for trastuzumab deruxtecan when HER2 is not overexpressed or amplified but is immunohistochemistry (IHC) 1+ or 2+ without amplification by in situ hybridization. Clinical trial data on tumors that tested IHC 0 are limited (excluded from DESTINY-Breast04), and evidence is lacking that these cancers behave differently or do not respond similarly to newer HER2 ADCs. Although current data do not support a new IHC 0 versus 1+ prognostic or predictive threshold for response to trastuzumab deruxtecan, this threshold is now relevant because of the trial entry criteria that supported its new regulatory approval. Therefore, while it is premature to create new result categories of HER2 expression (eg, HER2-Low, HER2-Ultra-Low), best practices to distinguish IHC 0 from 1+ are now clinically relevant. This Update affirms prior HER2 reporting recommendations and offers a new HER2 testing reporting comment to highlight the current relevance of IHC 0 versus 1+ results and best practice recommendations to distinguish these often subtle differences.Additional information is available at www.asco.org/breast-cancer-guidelines.
An Update Panel conducted a systematic literature review to identify signals for updating recommendations.
The search identified 173 abstracts. Of five potential publications reviewed, none constituted a signal for revising existing recommendations.
The 2018 ASCO-CAP recommendations for HER2 testing are affirmed.
HER2 testing guidelines have focused on identifying HER2 protein overexpression or gene amplification in breast cancer to identify patients for therapies that disrupt HER2 signaling. This update acknowledges a new indication for trastuzumab deruxtecan when HER2 is not overexpressed or amplified but is immunohistochemistry (IHC) 1+ or 2+ without amplification by in situ hybridization. Clinical trial data on tumors that tested IHC 0 are limited (excluded from DESTINY-Breast04), and evidence is lacking that these cancers behave differently or do not respond similarly to newer HER2 ADCs. Although current data do not support a new IHC 0 versus 1+ prognostic or predictive threshold for response to trastuzumab deruxtecan, this threshold is now relevant because of the trial entry criteria that supported its new regulatory approval. Therefore, while it is premature to create new result categories of HER2 expression (eg, HER2-Low, HER2-Ultra-Low), best practices to distinguish IHC 0 from 1+ are now clinically relevant. This Update affirms prior HER2 reporting recommendations and offers a new HER2 testing reporting comment to highlight the current relevance of IHC 0 versus 1+ results and best practice recommendations to distinguish these often subtle differences.Additional information is available at www.asco.org/breast-cancer-guidelines.
摘要：
更新ASCO-美国病理学家学院（CAP）对乳腺癌人类表皮生长因子受体2（HER2）检测的建议。专家组意识到，靶向HER2蛋白的新一代抗体-药物缀合物（ADC）对缺乏蛋白质过表达或基因扩增的乳腺癌具有活性。
更新小组进行了系统的文献综述，以确定更新建议的信号。
搜索确定了173个摘要。在审查的五个潜在出版物中，没有一个是修改现有建议的信号。
确认了2018年ASCO-CAP对HER2检测的建议。
HER2检测指南的重点是确定乳腺癌中HER2蛋白的过表达或基因扩增，以确定患者是否接受破坏HER2信号的治疗。此更新确认了当HER2未过度表达或扩增而是免疫组织化学（IHC）1或2+而未通过原位杂交扩增时，曲妥珠单抗deruxtecan的新适应症。测试IHC0的肿瘤的临床试验数据有限（从DESTINY-Breast04中排除），缺乏证据表明这些癌症对较新的HER2ADC表现不同或没有类似的反应。虽然目前的数据不支持新的IHC0与1+对曲妥珠单抗deruxtecan反应的预后或预测阈值，这个门槛现在是相关的，因为试验进入标准支持其新的监管批准。因此,虽然创建新的HER2表达结果类别还为时过早(例如，HER2-低,HER2-超低)，区分IHC0和1+的最佳实践现在具有临床相关性.本更新确认了以前的HER2报告建议，并提供了新的HER2测试报告评论，以突出IHC0与1+结果的当前相关性以及最佳实践建议，以区分这些通常细微的差异。其他信息可在www上获得。asco.org/乳腺癌指南。
更新小组进行了系统的文献综述，以确定更新建议的信号。
搜索确定了173个摘要。在审查的五个潜在出版物中，没有一个是修改现有建议的信号。
确认了2018年ASCO-CAP对HER2检测的建议。
HER2检测指南的重点是确定乳腺癌中HER2蛋白的过表达或基因扩增，以确定患者是否接受破坏HER2信号的治疗。此更新确认了当HER2未过度表达或扩增而是免疫组织化学（IHC）1或2+而未通过原位杂交扩增时，曲妥珠单抗deruxtecan的新适应症。测试IHC0的肿瘤的临床试验数据有限（从DESTINY-Breast04中排除），缺乏证据表明这些癌症对较新的HER2ADC表现不同或没有类似的反应。虽然目前的数据不支持新的IHC0与1+对曲妥珠单抗deruxtecan反应的预后或预测阈值，这个门槛现在是相关的，因为试验进入标准支持其新的监管批准。因此,虽然创建新的HER2表达结果类别还为时过早(例如，HER2-低,HER2-超低)，区分IHC0和1+的最佳实践现在具有临床相关性.本更新确认了以前的HER2报告建议，并提供了新的HER2测试报告评论，以突出IHC0与1+结果的当前相关性以及最佳实践建议，以区分这些通常细微的差异。其他信息可在www上获得。asco.org/乳腺癌指南。
