Department of Pathology, Fudan University Shanghai Cancer Center, Shanghai, 200032, China.
Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
Diagn Pathol. 2022 Jan 7;17(1):5. doi: 10.1186/s13000-021-01187-z.
According to 2018 ASCO/CAP guideline, HER2 FISH-equivocal breast cancers will be categorized as HER2 negative except those with IHC 3+. However, whether or not HER2 FISH-equivocal breast cancers was a heterogeneous group has not been well illustrated.
195 HER2 FISH-equivocal breast cancer samples were collected from 2014 to 2018. The molecular subtype was identified according to 2013 St Gallen consensus, and HER2 status was also re-determined following 2018 ASCO/CAP guideline. All samples were classified into 4 groups according to the average HER2 copy number (4.0-4.4, 4.5-4.9, 5.0-5.4, 5.5-5.9 signals/cell). The relationship between HER2 copy number and clinicopathological parameters was analyzed.
183 (93.8%) of 195 FISH-equivocal cases were classified as luminal-like subtype, while the other 12 (6.2%) were undetermined. Following 2018 ASCO/CAP guideline, all FISH-equivocal cases were recategorized as HER2 negative. Therefore, 31(15.9%) cases were luminal A-like, 152 (77.9%) were luminal B-like (HER2 negative) and 12 (6.2%) were triple negative. The average HER2 copy number showed a positive correlation with chromosome 17 polysomy, but had no significant association with other clinicopathological parameters as well as prognosis. 17 (8.7%) patients were treated with trastuzumab, but showed no difference in prognosis with those who didn't receive targeted therapy.
In this study, all HER2 FISH-equivocal breast cancers were recategorized as HER2 negative according to 2018 ASCO/CAP guideline. Most of these patients were luminal B-like (HER2 negative). The average HER2 copy number had no significant association with clinicopathological parameters, as well as prognosis.
根据 2018 年 ASCO/CAP 指南，HER2 FISH 不确定的乳腺癌将被归类为 HER2 阴性，除非免疫组化（IHC）结果为 3+。然而，HER2 FISH 不确定的乳腺癌是否为异质性群体尚未得到充分说明。
收集了 2014 年至 2018 年的 195 例 HER2 FISH 不确定的乳腺癌样本。根据 2013 年圣加仑共识，确定分子亚型，根据 2018 年 ASCO/CAP 指南，重新确定 HER2 状态。根据平均 HER2 拷贝数（4.0-4.4、4.5-4.9、5.0-5.4、5.5-5.9 信号/细胞）将所有样本分为 4 组。分析 HER2 拷贝数与临床病理参数之间的关系。
195 例 FISH 不确定病例中，183 例（93.8%）被归类为 luminal 样亚型，其余 12 例（6.2%）为不确定。根据 2018 年 ASCO/CAP 指南，所有 FISH 不确定病例均重新归类为 HER2 阴性。因此，31 例（15.9%）为 luminal A 样，152 例（77.9%）为 luminal B 样（HER2 阴性），12 例（6.2%）为三阴性。平均 HER2 拷贝数与染色体 17 三体呈正相关，但与其他临床病理参数及预后无显著相关性。17 例（8.7%）患者接受曲妥珠单抗治疗，但与未接受靶向治疗的患者预后无差异。
在这项研究中，根据 2018 年 ASCO/CAP 指南，所有 HER2 FISH 不确定的乳腺癌均重新归类为 HER2 阴性。这些患者大多为 luminal B 样（HER2 阴性）。平均 HER2 拷贝数与临床病理参数及预后无显著相关性。
