PHARMO Institute for Drug Outcomes Research, Utrecht, Netherlands.
University of Groningen, Groningen, Netherlands.
Breast. 2022 Dec;66:278-284. doi: 10.1016/j.breast.2022.11.003. Epub 2022 Nov 10.
With the introduction of investigational human epidermal growth factor receptor 2 (HER2) targeting treatments, thorough understanding of breast cancer with different HER2 expression levels is critical. The aim of this study was to compare clinicopathologic characteristics and survival of patients with metastatic breast cancer according to the level of HER2 expression.
Women with distant metastatic breast cancer during 2008-2016 were selected from PALGA, the Dutch Pathology Registry, and linked to the PHARMO Database Network. Breast cancer samples were categorised as HER2 immunohistochemistry score 0 (IHC0), HER2-low or HER2+.
Among women with hormone receptor (HR) positive metastatic breast cancer (n = 989), 373 (38%) cancers were HER2 IHC0, 472 (48%) were HER2-low and 144 (15%) were HER2+. Among HR negative patients (n = 272), the proportion of HER2 IHC0, HER2-low and HER2+ was 110 (40%), 104 (38%) and 58 (21%) respectively. Within the HR + cohort, patients with HER2 IHC0 or HER2-low cancer were significantly older compared to HER2+ patients. This age difference was not seen in the HR-cohort. The localisation of distant metastases differed significantly between HER2 IHC0 or HER2-low versus HER2+ cases. Survival rates did not differ markedly by subtypes.
Substantial proportion of patients had a HER2-low breast cancer. No clear differences in survival were found when comparing HER2 and HR status. Getting more granular insights in the level of HER2 expression and addressing HER2-low as a separate category could help to assess the impact of emerging treatment strategies. Therefore, more detailed information on HER2 expression should be routinely reported.
随着研究性人表皮生长因子受体 2（HER2）靶向治疗的引入，深入了解不同 HER2 表达水平的乳腺癌至关重要。本研究旨在比较根据 HER2 表达水平转移性乳腺癌患者的临床病理特征和生存情况。
从荷兰病理学登记处 PALGA 中选择 2008 年至 2016 年期间患有远处转移性乳腺癌的女性，并与 PHARMO 数据库网络进行链接。将乳腺癌样本分为 HER2 免疫组织化学评分 0（IHC0）、HER2-低或 HER2+。
在激素受体（HR）阳性转移性乳腺癌患者（n=989）中，373 例（38%）癌症为 HER2 IHC0，472 例（48%）为 HER2-低，144 例（15%）为 HER2+。在 HR 阴性患者（n=272）中，HER2 IHC0、HER2-低和 HER2+的比例分别为 110（40%）、104（38%）和 58（21%）。在 HR+队列中，HER2 IHC0 或 HER2-低癌症患者的年龄明显大于 HER2+患者。在 HR-队列中未观察到这种年龄差异。远处转移的部位在 HER2 IHC0 或 HER2-低与 HER2+病例之间存在显著差异。不同亚型的生存率无明显差异。
相当一部分患者患有 HER2-低乳腺癌。比较 HER2 和 HR 状态时，生存差异不明显。更详细地了解 HER2 表达水平并将 HER2-低作为单独类别进行处理，可以帮助评估新兴治疗策略的影响。因此，应常规报告更详细的 HER2 表达信息。
