非小细胞肺癌患者循环肿瘤细胞第7、8号染色体多体及其与组织中表皮生长因子受体基因突变的相关性

Detection of circulating tumor cells with chromosomes 7 and 8 polysomy in non-small cell lung cancer and its correlation with epidermal growth factor receptor mutations in cancer tissue

目的探讨在循环肿瘤细胞(circulating tumor cells,CTC)中检测第7、8号染色体多体在非小细胞肺癌辅助诊断中的价值及其与临床病理特征和组织中表皮生长因子受体(EGFR)基因突变的相关性。方法收集2017年11月至2020年10月首都医科大学附属北京朝阳医院诊治的57例非小细胞肺癌和21例肺部良性疾病患者资料,采用阴性富集联合免疫荧光原位杂交(imFISH)方法在CTC检测第7、8号染色体多体;其中56例肺癌患者用扩增阻滞突变系统(ARMS)PCR方法进行组织中EGFR基因突变检测。结果非小细胞肺癌组CTC检出率为93.0%(53/57),良性疾病组CTC检出率为28.6%(6/21),两者差异有统计学意义(P<0.01)。受试者工作特征(ROC)曲线显示,当cut-off为CTC≥1/3.2 mL外周血时,约登指数最大,灵敏度为93.0%,特异度为71.4%(ROC曲线下面积=0.906,95%CI:0.833~0.980,P<0.01)。Ⅲ~Ⅳ期患者CTC阳性率显著高于Ⅰ~Ⅱ期患者(P=0.023)。CTC阳性率和第7、8号染色体多体性与患者年龄、性别、吸烟史、病理类型和EGFR突变状态无显著相关性。EGFR突变组患者的CTC检出数目显著高于EGFR无突变组[(6.5±1.1)比(3.7±0.7),P=0.045],且突变组CTC检出数目≥5的患者比率显著高于无突变组(52.0%比19.4%,P=0.010)。结论检测第7、8号染色体多体CTC在非小细胞肺癌的辅助诊断中具有潜在价值,且CTC检出数目与患者的TNM分期和EGFR基因突变状态相关。

Objective To investigate the value of chromosomes 7 and 8 polysomy in circulating tumor cells(CTCs)for the diagnosis of non-small cell lung cancer,and the correlation of CTCs with clinical pathological characteristics and epidermal growth factor receptor(EGFR)mutations in cancer tissue.Methods Fifty-seven patients with non-small cell lung cancer and 21 patients with benign lung diseases were enrolled at Beijing Chaoyang Hospital,Capital Medical University,Beijing,China from November 2017 to October 2020.Negative enrichment combined with immunofluorescence in situ hybridization(imFISH)was used to identify CTCs polysomy on chromosomes 7 and 8.EGFR mutations in 56 lung cancer patients was detected using ARMS-PCR.Results CTCs were detected in 93.0%(53/57)of non-small cell lung cancers and 28.6%(6/21)benign lung lesions.The difference between lung cancer patients and the control cohort was statistically significant(P<0.01).Receive operator curve(ROC)analyses showed that,when the cut-off value was 1 cell/3.2 mL,Youden index had the highest sensitivity of 93.0%and specificity of 71.4%(AUC=0.906,95%CI:0.833-0.980,P<0.01).The positive rate of CTCs in stageⅢ-Ⅳcancers was significantly higher than that in stageⅠ-Ⅱ(P=0.023).No significant correlation was observed between positive rate of CTCs or chromosome polysomy and age,gender,smoking status,pathologic types and EGFR mutation status.The number of CTCs in EGFR mutated group was higher than that in the non-mutated group(6.5±1.1 vs.3.7±0.7,P=0.045).The detection rate for CTCs≥5 in the EGFR mutated group was also higher than the EGFR non-mutated group(52.0%vs.19.4%,P=0.010).Conclusion Detection of CTCs with chromosomes 7 and 8 polysomy has potential value in auxiliary diagnosis of non‐small cell lung cancer,and the number of CTCs is correlated to TNM stage and EGFR gene mutation status.