行新辅助治疗的交界性乳腺癌患者 HER2 免疫组化的回顾性观察性研究，重点关注 2 组（HER2/CEP17 比值≥2.0，HER2 拷贝数<4.0 个/细胞）病例。
Retrospective observational study of HER2 immunohistochemistry in borderline breast cancer patients undergoing neoadjuvant therapy, with an emphasis on Group 2 (HER2/CEP17 ratio ≥2.0, HER2 copy number <4.0 signals/cell) cases.
机构信息
Department of Histopathology, Nottingham University Hospitals, Nottingham, UK.
Nottingham Breast Cancer Research Centre, Division of Cancer and Stem Cells, School of Medicine, Nottingham City Hospital, The University of Nottingham, Nottingham, UK.
出版信息
Br J Cancer. 2021 May;124(11):1836-1842. doi: 10.1038/s41416-021-01351-8. Epub 2021 Mar 24.
BACKGROUND
The ASCO/CAP guidance on HER2 testing in breast cancer (BC) has recently changed. Group 2 tumours with immunohistochemistry score 2+ and HER2/CEP17 ratio ≥2.0 and HER2 copy number <4.0 signals/cell were re-classified as HER2 negative. This study aims to examine the response of Group 2 tumours to neoadjuvant chemotherapy (NACT).
METHODS
749 BC cases were identified from 11 institutions. The association between HER2 groups and pathological complete response (pCR) was assessed.
RESULTS
54% of immunohistochemistry HER2 positive (score 3+) BCs showed pCR, compared to 19% of immunohistochemistry 2+ FISH amplified cases. 27% of Group 2 treated with HER2 targeted therapy achieved pCR, compared to 19 and 11% in the combined Groups 1 + 3 and Groups 4 + 5, respectively. No difference in pCR rates was identified between Group 2 and Group 1 or combined Groups 1 + 3. However, Group 2 response rate was higher than Groups 4 + 5 (p = 0.017).
CONCLUSION
No difference in pCR was detected in tumours with a HER2/CEP17 ratio ≥2.0 and a HER2 score 2+ by IHC when stratified by HER2 gene copy number. Our data suggest that ASCO/CAP HER2 Group 2 carcinomas should be evaluated further with respect to eligibility for HER2 targeted therapy.
背景
最近，ASCO/CAP 关于乳腺癌（BC）中 HER2 检测的指南发生了变化。免疫组织化学评分 2+且 HER2/CEP17 比值≥2.0 且 HER2 拷贝数<4.0 信号/细胞的 2 组肿瘤被重新分类为 HER2 阴性。本研究旨在研究 2 组肿瘤对新辅助化疗（NACT）的反应。
方法
从 11 个机构中确定了 749 例 BC 病例。评估了 HER2 组与病理完全缓解（pCR）之间的关联。
结果
54%的免疫组织化学 HER2 阳性（评分 3+）BC 出现 pCR，而免疫组织化学 2+ FISH 扩增病例的 pCR 为 19%。接受 HER2 靶向治疗的 27%的 2 组患者达到了 pCR，而在联合 1+3 组和 4+5 组中，这一比例分别为 19%和 11%。在 pCR 率方面，2 组与 1 组或联合 1+3 组之间没有差异。然而，2 组的反应率高于 4+5 组（p=0.017）。
结论
在根据 HER2 基因拷贝数分层时，HER2/CEP17 比值≥2.0 且免疫组织化学评分 2+的肿瘤中，pCR 无差异。我们的数据表明，ASCO/CAP HER2 2 组癌应该进一步评估其是否适合接受 HER2 靶向治疗。
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