Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, United States of America.
PLoS One. 2020 Nov 12;15(11):e0241775. doi: 10.1371/journal.pone.0241775. eCollection 2020.
The 2018 American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guideline on HER2 testing in breast cancer permits reclassification of cases with HER2-equivocal results by FISH. The impact of such reclassification is unclear. We sought to determine the proportion of HER2-equivocal cases that are reclassified as HER2-negative and the impact of anti-HER2 therapy on survival in HER2-equivocal cases.
We reviewed medical records of breast cancer patients who had HER2 testing by fluorescence in stitu hybridization (FISH) and immunohistochemistry (IHC) performed or verified at The University of Texas MD Anderson Cancer Center during April 2014 through March 2018 and had equivocal results according to the 2013 ASCO/CAP guideline. The population was divided into 2 cohorts according to whether the biopsy specimen analyzed came from primary or from recurrent or metastatic disease. HER2 status was reclassified according to the 2018 ASCO/CAP guideline. Overall survival (OS) and event-free survival (EFS) were calculated using the Kaplan-Meier method, and the relationship between anti-HER2 therapy and clinical outcomes was assessed.
We identified 139 cases with HER2-equivocal results according to the 2013 ASCO/CAP guideline: 90 cases of primary disease and 49 cases of recurrent/metastatic disease. Per the 2018 ASCO/CAP guideline, these cases were classified as follows: overall, HER2-negative 112 cases (80%), HER2-positive 1 (1%), and unknown 26 (19%); primary cohort, HER2-negative 85 (94%), HER2-positive 1 (1%), unknown 4 (4%); and recurrent/metastatic, HER2-negative 27 (55%) and unknown 22 (45%). Five patients in the primary-disease cohort and 1 patient in the recurrent/metastatic-disease cohort received anti-HER2 therapy. There was no significant association between anti-HER2 therapy and OS or EFS in either cohort (primary disease: OS, p = 0.67; EFS, p = 0.49; recurrent/metastatic-disease, OS, p = 0.61; EFS, p = 0.78.
The majority of HER2-equivocal breast cancer cases were reclassified as HER2-negative per the 2018 ASCO/CAP guideline. No association between anti-HER2 therapy and OS or EFS was observed. HER2-equivocal cases seem to have clinical behavior similar to that of HER2-negative breast cancers.
2018 年美国临床肿瘤学会/美国病理学家协会（ASCO/CAP）乳腺癌 HER2 检测指南允许通过荧光原位杂交（FISH）对 HER2 结果不确定的病例进行重新分类。这种重新分类的影响尚不清楚。我们旨在确定 HER2 结果不确定的病例中有多少被重新分类为 HER2 阴性，以及在 HER2 结果不确定的病例中抗 HER2 治疗对生存的影响。
我们回顾了 2014 年 4 月至 2018 年 3 月期间在德克萨斯大学 MD 安德森癌症中心进行或验证的荧光原位杂交（FISH）和免疫组织化学（IHC）HER2 检测的乳腺癌患者的病历，这些患者的结果根据 2013 年 ASCO/CAP 指南为不确定。根据 2013 年 ASCO/CAP 指南，人群分为两组：一组为原发性疾病，另一组为复发性或转移性疾病。根据 2018 年 ASCO/CAP 指南对 HER2 状态进行重新分类。使用 Kaplan-Meier 方法计算总生存期（OS）和无事件生存期（EFS），并评估抗 HER2 治疗与临床结果之间的关系。
根据 2013 年 ASCO/CAP 指南，我们确定了 139 例 HER2 结果不确定的病例：原发性疾病 90 例，复发性/转移性疾病 49 例。根据 2018 年 ASCO/CAP 指南，这些病例分类如下：总体上，HER2 阴性 112 例（80%），HER2 阳性 1 例（1%），未知 26 例（19%）；原发性疾病队列，HER2 阴性 85 例（94%），HER2 阳性 1 例（1%），未知 4 例（4%）；复发性/转移性疾病，HER2 阴性 27 例（55%）和未知 22 例（45%）。原发性疾病队列中有 5 例和复发性/转移性疾病队列中有 1 例患者接受了抗 HER2 治疗。在两个队列中，抗 HER2 治疗与 OS 或 EFS 均无显著相关性（原发性疾病：OS，p=0.67；EFS，p=0.49；复发性/转移性疾病，OS，p=0.61；EFS，p=0.78）。
根据 2018 年 ASCO/CAP 指南，大多数 HER2 结果不确定的乳腺癌病例被重新分类为 HER2 阴性。未观察到抗 HER2 治疗与 OS 或 EFS 之间存在关联。HER2 结果不确定的病例似乎具有与 HER2 阴性乳腺癌相似的临床行为。
