Abstract：
Previous studies have observed that human epidermal growth factor receptor 2 (HER2)-low-positive patients and HER2-zero patients have different prognoses. This study was conducted to investigate whether there are differences in clinicopathological characteristics and the response to neoadjuvant systemic therapy (NST) defined as systemic treatment prior to surgery between HER2-low-positive patients and HER2-zero patients. We retrospectively analyzed the data of patients with HER2-negative breast cancer who received NST at the First Affiliated Hospital of Nanjing Medical University from 2014 to 2021. There were 238 patients with HER2-low-positive status and 198 patients with HER2-zero status. The proportion of hormone receptor (HR)-positive patients in the HER2-low-positive group was significantly higher than that in the HER2-zero group (82.8% vs 52.0%, p < 0.001). The HER2-low-positive group had more patients with low Ki67 expression (23.9% vs 16.2%, p = 0.045), higher mastectomy rate (94.5% vs 88.9%, p = 0.031), and larger pathological tumor size (21.6 vs 17.8 mm, p = 0.028) than the HER2-zero group. However, no significant differences were found in pathologic complete response (pCR) rates between the two groups. We draw a conclusion that patients with HER2-low status and HER2-zero status were not found to have different pCR rates after NST, irrespective of HR status. However, differences were observed in some clinicopathological characteristics between the two groups.
摘要：
先前的研究已经观察到人类表皮生长因子受体2（HER2）-低阳性患者和HER2-零患者具有不同的预后。这项研究旨在调查HER2低阳性患者和HER2零患者之间的临床病理特征和对新辅助全身治疗（NST）的反应是否存在差异。回顾性分析2014-2021年南京医科大学第一附属医院接受NST治疗的HER2阴性乳腺癌患者的临床资料。有238例HER2低阳性状态患者和198例HER2零状态患者。HER2低阳性组中激素受体（HR）阳性患者的比例明显高于HER2零组（82.8％vs52.0％，p<0.001)。HER2低阳性组的Ki67低表达患者较多（23.9%vs16.2%，p=0.045),较高的乳房切除术率(94.5%vs88.9%，p=0.031),和较大的病理肿瘤大小（21.6vs17.8mm，p=0.028）比HER2零组。然而,两组间病理完全缓解(pCR)率无显著差异.我们得出结论，在NST后，未发现HER2低状态和HER2零状态的患者具有不同的pCR率，不管HR的地位。然而,两组间的一些临床病理特征存在差异。
