肺癌细胞学及血液标本表皮生长因子受体基因突变对比研究

Comparative study of epidermal growth factor receptor mutation analysis on cytology and blood specimens from lung carcinomas

目的:研究肺癌患者渗出液细胞学及血液标本中表皮生长因子受体(EGFR)第18、19、21外显子基因突变频率和类型以及与肿瘤组织学标本的关系。方法:收集肺癌患者渗出液细胞学标本53例及血液标本24例,提取DNA,聚合酶链反应扩增EGFR外显子18、19、21序列,用直接测序法检测基因序列,分析EGFR基因突变频率和类型以及与肿瘤组织学标本的关系。结果:53例细胞学标本检测到15例EGFR基因突变(28.3%,15/53),18外显子突变1例,19外显子突变5例,21外显子突变9例,细胞学标本与肺腺癌组织学标本突变率(32.2%)相比,差异没有显著性(P=0.624)。24例血液标本中检测到1例突变(4.2%,1/24),位于21外显子,血液标本与肿瘤组织学标本突变率相比,差异有显著性(P=0.006)。结论:肺癌患者渗出液细胞学标本适用于直接测序法检测EGFR突变,血液标本不适于用直接测序法检测肿瘤EGFR基因突变状态。

Objective：To determine the frequency and type of epidermal growth factor receptor（EGFR）exon 18, 19,21 exon mutations in cytology and blood specimens from lung carcinomas. To explore the relationship of EGFR mu-tation from cytology versus histology specimes. Methods：All 53 cytology specimens and 24 blood specimens were col-lected from patients with lung cancer. The tissue DNA was abstracted and the exons 18,19,21 in EGFR gene were subjected for PCR amplification and direct sequencing. Results：EGFR mutations were detected in 15 of 53 cytology specimens（28. 3% ）,the frequencies of EGFR mutations in exons 18,19 and 21 were 1. 9%（1 / 53）,9. 4%（5 / 53） and 16. 9%（9 / 53）,respectively. There were no signifiant differences in the EGFR mutation rate between cytology samples and histology samples（28. 3 % VS 32. 2% ,P = 0. 624）,but significant differences were found in the blood samples（4. 2% ,1 / 24,located in the exon 21）compared with histology samples（P = 0. 006）. Conclusion：The cur-rent results indicate that direct extraction and analysis of EGFR mutations from cytology samples can be performed successfully on a direct sequencing platform. Peripheral blood is not a suitable compartment for detection of tumor cells in lung cancer.