乳腺癌HER2低表达对新辅助化疗疗效影响的临床观察

Impact of HER2 low expression on neoadjuvant chemotherapy in breast cancer:A single- center,small-sample retrospective study

目的:分析比较HER2低表达与阴性乳腺癌患者的临床病理特征,并探讨HER2低表达对新辅助化疗疗效的影响。方法:收集2018年01月至2021年10月在本单位接受新辅助化疗的乳腺癌患者的临床病理信息,根据HER2免疫组化(IHC)及原位杂交(ISH)结果,将IHC 1+或2+且ISH阴性患者纳入HER2低表达组,将IHC 0患者纳入HER2阴性组,比较两组患者新辅助化疗疗效及预后的差异,比较化疗前后原发灶HER2表达水平的差异。结果:本研究共纳入96例乳腺癌患者,其中HER2阴性患者占39.58%,HER2低表达占60.42%;HER2阴性与低表达组在年龄、体质量指数、月经状态、激素受体状态、组织分级、肿瘤大小、腋窝淋巴结阳性率等方面均无显著差异,但阴性组Ki-67>30%的占比大于低表达组(86.84%vs 68.97%,P=0.05);新辅助化疗后,两组患者的病理完全反应(pathology complete response,pCR)率无显著差异,但HER2阴性组原发灶Miller&Payne分级≥4级的占比(36.84%)显著高于HER2低表达组(17.24%)(P=0.03)。亚组分析显示,无论是在HER2阴性组还是低表达组,激素受体阳性(HR+)患者的局部治疗反应均差于HR-患者,且HR+乳腺癌化疗后更易出现HER2免疫组化评分的升级。生存分析显示,两组的无病生存期(disease-free survival,DFS)无显著差异。结论:HER2低表达乳腺癌具有更低的增殖活性,但对新辅助化疗的局部治疗反应差于HER2阴性乳腺癌,提示HR状态在化疗后HER2的异质性表达以及化疗耐药中可能发挥作用。

Objective:To analyze clinicopathological features between breast cancer patients with HER2 low and negative expression,and to discusse the impact of HER2 low expression on the efficacy of neoadjuvant chemotherapy was discussed.Methods:The clinicopathological parameters of patients who received neoadjuvant chemotherapy in our department from January 2018 to October 2021 were collected.Patients with HER2 immunohistochemistry(IHC)1+or 2+butin situ hybridization(ISH)negative were included in the HER2 low expression group,and patients with IHC 0 were included in the HER2 negative group.The efficacy and prognosis of chemotherapy were compared between the two groups.Besides,the differences of HER2 expression levels before and after chemotherapy were investigated to explore the relationship between chemotherapy and HER2 heterogeneity.Results:A total of 96 patients were included in this study.Among them,39.58%were HER2 negative breast cancers and 60.42%were HER2 low expression breast cancers.There were no significant differences in age,body mass index,menstrual status,hormone receptor(HR)status,tissue grade,tumor size and axillary lymph node positive rate between the two groups.The proportion of patients with Ki-67>30%in the HER2 low expression group was smaller than that in the negative group(P=0.05).There was no significant difference in pathological complete response rate between the two groups.In the HER2 negative group,36.84%of patients had Miller&Payne score≥4,but the proportion was only 17.24%in HER2 low expression group(P=0.03).Subgroup analysis showed that HR+patients had worse local treatment response than HR-patients whatever in HER2 negative group or low group.Besides,HR+patients were more likely to have an upgrade of HER2 IHC score after chemotherapy.Survival analysis showed no significant difference in DFS between the two groups. Conclusion: In this study,HER2 low expression breast cancer had lower proliferation activity,but local treatment response to neoadjuvant chemotherapy was worse than that of HER2 negative breast cancer.HR status might play a role in HER2 heterogeneous expression after chemotherapy and cause drug resistance.