Sakatani Takashi, Tsuda Hitoshi, Yoshida Masayuki, Honma Naoko, Masuda Shinobu, Osako Tomo, Hayashi Amiko, Jara-Lazaro Ana Richelia, Horii Rie
Department of Diagnostic Pathology, Nippon Medical School Hospital, 1-1-5, Sendagi, Bunkyo-Ku, Tokyo, 113-8603, Japan.
Department of Basic Pathology, National Defense Medical College, Saitama, Japan.
Breast Cancer Res Treat. 2025 Feb;210(1):27-36. doi: 10.1007/s10549-024-07532-2. Epub 2024 Nov 4.
This study aimed to assess the concordance of human epidermal growth factor receptor 2 (HER2) expression scoring by immunohistochemistry (IHC) among practicing pathologists in Japan, given the challenging nature of scoring and the critical role of HER2 status in breast cancer management.
Whole slide images (WSI) from 20 invasive breast cancer cases (1 representative WSI per case) selected to represent a diverse IHC scores and staining patterns were used in an online survey involving seven reference pathologists who established consensus HER2 IHC scores (0 to 3 +) decided by majority interpretation. Participating pathologists nationwide scored the same 20 WSI cases online using the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) 2018 guidelines. Deidentified case metadata were registered in the uPath system.
A total of 144 participating pathologists responded. The scoring results of the participating pathologists most commonly agreed with the consensus IHC score, followed by a ± 1 point deviation and no survey responses with > 1 point deviation. The mean percentage of agreement with the consensus score for all 20 cases was 63.4%. In cases where the reference pathologists' scores were discordant, the participating pathologists also showed a lower concordance rate.
This study highlighted the current status of HER2 expression scoring by IHC for breast cancer among pathologists in Japan. These findings underscore the challenges in HER2 IHC scoring cases and emphasize the need for improved standardization and training, especially in the evolving landscape of HER2-targeted therapies.
鉴于人表皮生长因子受体2（HER2）表达评分具有挑战性，且HER2状态在乳腺癌管理中起着关键作用，本研究旨在评估日本执业病理学家通过免疫组织化学（IHC）对HER2表达进行评分的一致性。
从20例浸润性乳腺癌病例（每个病例1张代表性全切片图像）中选取全切片图像，这些病例代表了不同的免疫组化评分和染色模式，用于一项在线调查，该调查涉及7名参考病理学家，他们通过多数解释确定了HER2免疫组化的共识评分（0至3 +）。全国参与调查的病理学家使用美国临床肿瘤学会/美国病理学家学会（ASCO/CAP）2018年指南对相同的20例全切片图像病例进行在线评分。去识别化的病例元数据在uPath系统中进行了登记。
共有144名参与调查的病理学家做出了回应。参与调查的病理学家的评分结果最常与共识免疫组化评分一致，其次是相差±1分，没有相差超过1分的调查回复。所有20例病例与共识评分的平均一致率为63.4%。在参考病理学家评分不一致的病例中，参与调查的病理学家的一致率也较低。
本研究突出了日本病理学家通过免疫组化对乳腺癌HER2表达进行评分的现状。这些发现强调了HER2免疫组化评分病例中的挑战，并强调了改进标准化和培训的必要性，特别是在HER2靶向治疗不断发展的背景下。
