Li K M, Wu S F, Sun M C, Zhang H X, Teng X Y, Liu Y Y, Liang Z Y, Zeng X
Department of Pathology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China.
Zhonghua Bing Li Xue Za Zhi. 2024 Jul 8;53(7):691-696. doi: 10.3760/cma.j.cn112151-20240315-00167.
To investigate the clinical and pathological characteristics of breast cancer with HER2 low expression. The data from 3 422 patients with invasive breast cancer which archived in Peking Union Medical College Hospital between April 2019 and July 2022 were retrospectively reviewed. Among them, 136 patients were treated with neoadjuvant chemotherapy. The tumor size, histological type, tumor differentiation, lymph node metastasis, Ki-67 index, the status of estrogen receptor, progesterone receptor and HER2 as well as pathological complete response (pCR) rate were collected. The HER2 status of 3 286 patients without neoadjuvant therapy, 616 (616/3 286, 18.7%) score 0, 1 047 (1 047/3 286, 31.9%) score 1+, 1 099 (1 099/3 286,33.4%) score 2+ and 524 (524/3 286,15.9%) score 3+ by immunohistochemistry (IHC). Among the 1 070 IHC 2+ cases, 161 were classified as HER2 positive by reflex fluorescence in situ hybridization (FISH) assay. In our cohort, 1 956 cases of HER2-low (IHC 1+ and IHC 2+/FISH-) breast cancer were identified. Compared to the HER2 IHC 0 group, HER2-low tumors more frequently occurred in patients with hormone receptor (HR) positive (<0.001), Ki-67 index below 35% (<0.001), well or moderate differentiation (<0.001) and over the age of 50 (=0.008). However, there were no significant differences in histological type, tumor size, and lymph node metastasis between HER2-low and HER2 IHC 0 group. For patients who had neoadjuvant therapy, the pCR rate in the patients with HER2-low was lower than those with HER2 IHC 0 (13.3%, 23.9%), but there was no significant difference. Although HER2-low breast cancers showed a slightly lower pCR rate than HER2 IHC 0 tumors, no remarkable difference was observed between tumors with HER2-low and HER2 IHC 0 regardless of hormone receptor status. The clinicopathological features of HER2-low breast cancers are different from those with HER2 IHC 0. It is necessary to accurately distinguish HER2-low breast cancer from HER2 IHC 0 and to reveal whether HER2-low tumor is a distinct biological entity.
探讨HER2低表达乳腺癌的临床及病理特征。回顾性分析2019年4月至2022年7月存档于北京协和医院的3422例浸润性乳腺癌患者的数据。其中，136例患者接受了新辅助化疗。收集肿瘤大小、组织学类型、肿瘤分化程度、淋巴结转移情况、Ki-67指数、雌激素受体、孕激素受体及HER2状态以及病理完全缓解（pCR）率。对3286例未接受新辅助治疗的患者进行HER2状态检测，免疫组化（IHC）结果显示，616例（616/3286，18.7%）评分为0，1047例（1047/3286，31.9%）评分为1+，1099例（1099/3286，33.4%）评分为2+，524例（524/3286，15.9%）评分为3+。在1070例IHC 2+病例中，161例经荧光原位杂交（FISH）检测被分类为HER2阳性。在我们的队列中，共识别出1956例HER2低表达（IHC 1+和IHC 2+/FISH-）乳腺癌病例。与HER2 IHC 0组相比，HER2低表达肿瘤更常见于激素受体（HR）阳性（<0.001）、Ki-67指数低于35%（<0.001）、高分化或中分化（<0.001）以及年龄超过50岁（=0.008）的患者。然而，HER2低表达组与HER2 IHC 0组在组织学类型、肿瘤大小和淋巴结转移方面无显著差异。对于接受新辅助治疗的患者，HER2低表达患者的pCR率低于HER2 IHC 0患者（13.3%对23.9%），但差异无统计学意义。尽管HER2低表达乳腺癌的pCR率略低于HER2 IHC 0肿瘤，但无论激素受体状态如何，HER2低表达肿瘤与HER2 IHC 0肿瘤之间均未观察到显著差异。HER2低表达乳腺癌的临床病理特征与HER2 IHC 0乳腺癌不同。准确区分HER2低表达乳腺癌与HER2 IHC 0乳腺癌并揭示HER2低表达肿瘤是否为独特的生物学实体很有必要。
