血清HER2-ECD水平在乳腺癌新辅助化疗中的应用价值分析

背景与目的：人类表皮生长因子受体-2（human epidermal growth factor receptor-2，HER2）是一种原癌基因所表达的蛋白，HER2阳性往往预示着肿瘤进展快、容易发生淋巴结或血道转移，对新辅助化疗不敏感，预后不佳。本研究通过对乳腺癌患者血清HER2胞外段（extracellular domain，ECD）水平与患者临床新辅助化疗的反应性的比较，来评估血清HER2-ECD在新辅助化疗评估中的价值。方法：收集507例乳腺癌患者的治疗前血清样本，利用χ2检验比较血清HER2-ECD与患者年龄、分期、组织雌激素受体、孕激素受体、Ki-67及HER2的关系，对其中48例HER2表达阳性的行新辅助化疗的乳腺癌患者予以随访，单因素分析治疗前后血清HER2-ECD水平变化与新辅助化疗疗效之间的关系。结果：通过对507例患者血清HER2-ECD和临床病理特征的比较发现，在年龄>50岁、Ⅲ~Ⅳ期、组织雌激素受体（-）、孕激素受体（-）、Ki-67>20%及HER2（+）的患者中血清HER2-ECD阳性率较高。对48例组织HER2阳性的患者随访发现，血清HER2-ECD在治疗2个周期后即出现大幅下降，从18.10 ng/mL（13.20~28.95 ng/mL）降低到11.20 ng/mL（9.80~12.75 ng/mL）（P<0.01）。对48例患者进行疗效评估发现，新辅助化疗2个周期后血清HER2-ECD阴性的患者其客观缓解率（94.7%，36/38）显著高于治疗后血清HER2-ECD阳性的患者（60.0%，6/10）（P<0.05）。结论：乳腺癌患者血清HER2-ECD升高与其年龄、分期、组织雌激素受体、孕激素受体及Ki-67相关，且新辅助化疗2个周期后的血清HER2-ECD水平对新辅助化疗的疗效有一定的评估作用。

The value of serum HER2-ECD level in neoadjuvant chemotherapy for breast cancer

Background and purpose: Human epidermal growth factor receptor-2 (HER2) is a protein expressed by an oncogene, and HER2 positivity tends to indicate rapid tumor progression, susceptibility to lymph node or organ metastasis, resistance to neoadjuvant chemotherapy and poor prognosis. In this study, we investigated the role of serum extracellular domain (ECD) of HER2 in the evaluation of the outcome of patients with breast cancer after neoadjuvant chemotherapy. Methods: A total of 507 serum samples from patients with breast cancer were collected, and Chi-square test was used to compare the age, stage and tissue estrogen receptor, progesterone receptor, Ki-67 and HER2 status with serum HER2-ECD. Forty-eight patients with HER2-positive breast cancer who underwent neoadjuvant chemotherapy were followed up. The serum samples before treatment, after 2 cycles, 4 cycles and 6 cycles were collected. The relationship between the change of serum HER2-ECD levels before and after the treatment and the efficacy of neoadjuvant chemotherapy was analyzed. Results: By comparing serum HER2-ECD and clinic-pathological features of 507 patients, elevated serum HER2-ECD was found in patients ages over 50 years who had stage Ⅲ-Ⅳ breast cancer tissue estrogen receptor (-), progesterone receptor (-) and Ki-67>20%. A follow-up of 48 patients with HER2-positive tissue showed a significant decrease in serum HER2-ECD after 2 cycles of neoadjuvant chemotherapy, from 18.10 ng/mL (13.20-28.95 ng/mL) to 11.20 ng/mL (9.80-12.75 ng/mL) (P<0.01). By evaluating the efficacy of neoadjuvant chemotherapy, we found that the objective response rate in patients with negative serum HER2-ECD (94.7%, 36/38) was significantly higher than that in patients with positive serum HER2-ECD (60.0%, 6/10) (P<0.05). Conclusion: The increase of serum HER2-ECD in breast cancer patients is related to age, stage and tissue estrogen receptor, progesterone receptor and Ki-67, and the level of serum HER2-ECD after 2 cycles of neoadjuvant chemotherapy plays an important role in evaluating the response to neoadjuvant chemotherapy in patients with breast cancer.