Table1_HER2 status of CTCs by peptide-functionalized nanoparticles as the diagnostic biomarker of breast cancer and predicting the efficacy of anti-HER2 treatment.PDF

Efficacy of anti-human epidermal growth factor receptor 2 (HER2) treatment is impacted by tissue-based evaluation bias due to tumor heterogeneity and dynamic changes of HER2 in breast cancer. Circulating tumor cell (CTC)-based HER2 phenotyping provides integral and real-time assessment, benefiting accurate HER2 diagnosis. This study developed a semi-quantitative fluorescent evaluation system of HER2 immunostaining on CTCs by peptide-functionalized magnetic nanoparticles (Pep@MNPs) and immunocytochemistry (ICC). 52 newly-diagnosed advanced breast cancer patients were enrolled for blood samples before and/or after first-line treatment, including 24 patients who were diagnosed with HER2+ tumors and treated with anti-HER2 drugs. We enumerated CTCs and assessed levels of HER2 expression on CTCs in 2.0 ml whole blood. Enumerating CTCs at baseline could distinguish cancer patients (sensitivity, 69.2%; specificity, 100%). 80.8% (42/52) of patients had at least one CTCs before therapy. Patients with <3 CTCs at baseline had significantly longer progression-free survival (medians, 19.4 vs. 9.2 months; log-rank p = 0.046) and overall survival (medians, not yet reached; log-rank p = 0.049) than those with ≥3 CTCs. Both HER2+ and HER2-low patients could be detected with HER2 overexpression on CTCs (CTC-HER2+) (52.6%, 44.4%, respectively), whereas all the HER2-negative patients had no CTC-HER2+ phenotype. Among HER2+ patients with ≥3 CTCs at baseline, objective response only appeared in pretherapeutic CTC-HER2+ cohort (60.0%), rather than in CTC-HER2– cohort (0.0%) (p = 0.034). In conclusion, we demonstrate the significance of CTC enumeration in diagnosis and prognosis of first-line advanced breast cancer, and highlight the value of CTC-HER2 status in predicting efficacy of anti-HER2 treatment.

抗人表皮生长因子受体2（HER2）治疗的疗效会受到乳腺癌中肿瘤异质性与HER2动态变化所导致的基于组织的评估偏倚影响。基于循环肿瘤细胞（CTC）的HER2表型分型可提供完整且实时的评估，有助于实现精准的HER2诊断。本研究构建了一套基于肽功能化磁性纳米颗粒（Pep@MNPs）与免疫细胞化学（ICC）的CTC表面HER2免疫染色半定量荧光评估体系。本研究纳入52例新确诊的晚期乳腺癌患者，采集其一线治疗前和/或治疗后的血液样本，其中包括24例确诊为HER2阳性肿瘤且接受抗HER2药物治疗的患者。我们对2.0ml全血中的CTC进行计数，并评估CTC表面的HER2表达水平。基线CTC计数可区分癌症患者（灵敏度69.2%；特异度100%）。80.8%（42/52）的患者在治疗前可检出至少1个CTC。基线CTC计数＜3个的患者，其无进展生存期（中位值：19.4 vs 9.2个月；log-rank检验p=0.046）与总生存期（中位值：尚未达到；log-rank检验p=0.049）均显著长于基线CTC计数≥3个的患者。CTC表面HER2过表达（CTC-HER2+）可在HER2阳性与HER2低表达患者中分别检出（占比分别为52.6%、44.4%），而所有HER2阴性患者均未检出CTC-HER2+表型。在基线CTC计数≥3个的HER2阳性患者中，仅在治疗前CTC-HER2+队列中观察到客观缓解（占比60.0%），而非CTC-HER2-队列（占比0.0%）（p=0.034）。综上，本研究证实了CTC计数在一线治疗晚期乳腺癌的诊断与预后评估中的重要价值，并凸显了CTC-HER2状态在预测抗HER2治疗疗效中的应用价值。