From the Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, China.
Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, China.
Arch Pathol Lab Med. 2020 Sep 1;144(9):1097-1107. doi: 10.5858/arpa.2019-0369-OA.
CONTEXT.—: The updated American Society of Clinical Oncology/College of American Pathologists guideline for human epidermal growth factor receptor 2 (HER2) testing in breast cancer requires pathologists to re-evaluate HER2 status.
OBJECTIVE.—: To define HER2 status of breast cancer using immunohistochemistry and fluorescence in situ hybridization.
DESIGN.—: Diagnostic reports of invasive breast cancers made between 2014 and 2018 with HER2 immunohistochemistry and fluorescence in situ hybridization results were retrieved. HER2 status was re-defined using the updated recommendations.
RESULTS.—: Of 2514 tumors, 89.7% (2254 of 2514) suggested for fluorescence in situ hybridization assay were HER2 immunohistochemistry 2+. Approximately 8.9% (225 of 2514) and 1.4% (35 of 2514) of tumors were of immunohistochemistry 0/1+ and 3+, respectively. Based on the average HER2 copy number and HER2:CEP17 ratio, tumors were assigned into 5 groups, including 13.1% (330 of 2514) group 1 tumors, 2.1% (52 of 2514) group 2 tumors, 1.1% (27 of 2514) group 3 tumors, 7.0% (175 of 2514) group 4 tumors, and 76.8% (1930 of 2514) group 5 tumors. In combination with immunohistochemistry, all tumors in group 2 and group 4 changed HER2 status, from positive and equivocal into negative, respectively, while group 3 tumors remained positive. Comparative analyses of clinicopathologic features of tumors in different groups revealed that group 2 and 4 tumors displayed worse clinicopathologic features than those of group 5, while group 3 tumors shared similar clinicopathologic features to those of group 1.
CONCLUSIONS.—: Following the updated guideline, HER2 status is clearly designated. Significant differences regarding clinical features were observed between tumors in different groups but they share the same HER2 status, suggesting further validation of the accuracy of this diagnostic approach is warranted.
美国临床肿瘤学会/美国病理学家学院更新的人表皮生长因子受体 2（HER2）检测在乳腺癌中的指南要求病理学家重新评估 HER2 状态。
使用免疫组织化学和荧光原位杂交技术定义乳腺癌的 HER2 状态。
检索了 2014 年至 2018 年间进行的浸润性乳腺癌的免疫组织化学和荧光原位杂交结果的诊断报告。使用更新的建议重新定义 HER2 状态。
在 2514 例肿瘤中，89.7%（2254/2514）建议进行荧光原位杂交检测的肿瘤为 HER2 免疫组织化学 2+。大约 8.9%（225/2514）和 1.4%（35/2514）的肿瘤分别为免疫组织化学 0/1+和 3+。根据平均 HER2 拷贝数和 HER2:CEP17 比值，将肿瘤分为 5 组，包括 13.1%（330/2514）组 1 肿瘤、2.1%（52/2514）组 2 肿瘤、1.1%（27/2514）组 3 肿瘤、7.0%（175/2514）组 4 肿瘤和 76.8%（1930/2514）组 5 肿瘤。结合免疫组织化学，组 2 和组 4 的所有肿瘤 HER2 状态均发生变化，从阳性和不确定变为阴性，而组 3 肿瘤仍为阳性。对不同组肿瘤的临床病理特征进行比较分析显示，组 2 和组 4 的肿瘤比组 5 的肿瘤具有更差的临床病理特征，而组 3 的肿瘤与组 1 的肿瘤具有相似的临床病理特征。
按照更新的指南，HER2 状态被明确指定。不同组之间的肿瘤在临床特征方面存在显著差异，但它们具有相同的 HER2 状态，这表明需要进一步验证这种诊断方法的准确性。
