晚期非小细胞肺癌外周血CTC 与肿瘤组织EGFR 表达的相关性

Correlation between EGFR expression in circulating tumor cells and in tumor tissues of advanced non-small cell lung cancer

摘要:

目的 探讨晚期非小细胞肺癌（NSCLC）外周血循环肿瘤细胞（CTC）与肿瘤组织表皮生长因子受体（EGFR）表达的一致性。方法 利用流式细胞术及免疫组织化学染色配对检测66 例NSCLC患者外周血CTC 和肿瘤组织EGFR 的表达水平。给予EGFR 酪氨酸激酶抑制剂治疗1 个月后进行疗效评价。比较CTC 与肿瘤组织EGFR 表达的一致性，并分析其与患者临床因素、疗效及预后的相关性。结果 外周血CTC 与肿瘤组织EGFR 表达一致率为69.7%。CTC 与肿瘤组织EGFR 的表达在不同组织学类型间比较，差异有统计学意义（P <0.5），在不同性别、年龄、分期、体力活动状态评分方面比较，差异无统计学意义（P >0.05）。EGFR 高表达组疾病控制率高于低表达组（CTC ：87.5% vs 35.3% ；肿瘤组织：72.7%vs 36.4%）（P <0.05）。生存分析结果显示，EGFR 高表达组有更长的无进展生存期（CTC ：8 个月 vs 2 个月；肿瘤组织：6 个月 vs 2 个月）和总生存期（CTC：20 个月 vs 13 个月；肿瘤组织：16 个月 vs 14 个月）（P <0.05）。结论 晚期NSCLC 患者外周血CTC 和肿瘤组织EGFR 表达的一致性好，两者对酪氨酸激酶抑制剂治疗的疗效及预后具有一定的预测价值。外周血CTC 作为肿瘤组织的替代检测标本是可行的。

Abstract:

Objective To detect the expression level of epidermal growth factor receptor (EGFR) in circulating tumor cells (CTC) and matched tumor tissues from patients with advanced non-small cell lung cancer (NSCLC),and investigate the consisitent rate of these two methods. Methods The EGFR expression was analyzed by flow cytometry and immunohistochemical staining in the peripheral blood CTC and tumor tissues from 66 advanced NSCLC patients. The therapeutic efficacy was evaluated after 1 month of treatment with EGFR-tyrosine kinase inhibitor (EGFR-TKI). The consistency of the EGFR expression in the CTC and the tumor tissues was compared.The relationships of EGFR expression with clinical characteristics, efficacy, progression-free survival (PFS) and overall survival (OS) were analyzed. Results The consistent rate of the two methods was 69.7% (46/66, P < 0.05).The EGFR expression levels in the CTC and the tumor tissues were significantly different between the patients with different pathological types (P < 0.05), but not statistically different between the patients with different gender, age, clinical stage or PS score (P > 0.05). The patients with high EGFR expression level had remarkably higher disease control rate than those with low EGFR expression level (CTC: 87.5% vs. 35.3%; tumor tissue: 72.7% vs. 36.4%; P < 0.05), longer PFS (CTC: 8 months vs. 2 months; tumor tissue: 6 months vs. 2 months; P < 0.05) and OS (CTC: 20 months vs. 13 months; tumor tissue: 16 months vs. 14 months; P < 0.05). Conclusions In the patients with advanced NSCLC, EGFR expression level in the CTC and the tumor tissues is highly consistent. Both of them can be used for predicting the efficacy of EGFR-TKI therapy and prognosis. CTC can be a substitute for tumor tissue.