Department of Pathology, the first affiliated hospital of Zhejiang University, Qingchun Road 79#, Hangzhou, China.
Sci Rep. 2019 Nov 13;9(1):16726. doi: 10.1038/s41598-019-53003-w.
The American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) recently issued updated guidelines on human epidermal growth factor receptor 2 (HER2) testing by fluorescence in situ hybridization (FISH) in invasive breast cancers. In this study, we aimed to investigate the impact of the new recommendations on HER2 FISH interpretation in invasive breast cancers with immunohistochemically (IHC) equivocal results. 1810 breast cancer cases with IHC equivocal results were enrolled in this study between January 2012 and May 2019. Concomitant IHC was performed on the same tissue blocks detected by FISH testing. According to the 2018 guidelines, all the cases in ISH group 2 were categorized as HER2 negative; three of four cases in ISH group 3 were considered as HER2 positive, while the one scored IHC 1+ was reclassified as HER2 negative; Fifty-three previously ISH equivocal cases were redistributed into ten HER2-positive cases and forty-three HER2-negative cases. In conclusion, the utility of 2018 ASCO/CAP guidelines resulted in a slight decrease in HER2 positive rate, due to the reclassification of cases in ISH group 2 and group 4. The implementation of the new guidelines can reduce reflex FISH test and make the diagnosis of HER2 gene status more definitive.
美国临床肿瘤学会（ASCO）/美国病理学家协会（CAP）最近发布了更新的荧光原位杂交（FISH）检测浸润性乳腺癌人表皮生长因子受体 2（HER2）的指南。本研究旨在探讨新推荐意见对免疫组织化学（IHC）结果不确定的浸润性乳腺癌 HER2 FISH 检测结果的影响。2012 年 1 月至 2019 年 5 月期间，共纳入了 1810 例 IHC 结果不确定的乳腺癌病例。在同一组织块上同时进行了伴随的 IHC 检测。根据 2018 年指南，ISH 组 2 中的所有病例均被归类为 HER2 阴性；ISH 组 3 中的四例中有三例被认为是 HER2 阳性，而 IHC 评分为 1+的病例被重新归类为 HER2 阴性；53 例先前 ISH 不确定的病例被重新分配为 10 例 HER2 阳性病例和 43 例 HER2 阴性病例。总之，由于 ISH 组 2 和组 4 病例的重新分类，2018 年 ASCO/CAP 指南的应用导致 HER2 阳性率略有下降。新指南的实施可以减少反射性 FISH 检测，使 HER2 基因状态的诊断更加明确。
