EGFR Methylation in Peripheral Blood of Driver Gene-Positive Lung Cancer and its Clinical Correlation / 医学研究杂志

ABSTRACT

Objective To explore the methylation status of EGFR promoter region in peripheral blood of EGFR driver gene-positive lung adenocarcinoma patients and its clinical significance.Methods The methylation of EGFR promoter region in peripheral blood DNA of 32 EGFR driver gene-positive lung adenocarcinoma patients and 24healthy controls were detected by(matrix-assisted laser desorp-tion/ionisation,time-of-flight mass spectrometry,MALDI-TOF MS)technique to screen the differential methylation of CpG sites with lung cancer and analyze its correlation with clinicopathological characteristics and EGFR mutant subtype.Results The methylation levels of EGFR were significantly lower in the lung cancer group than in the normal control,EGFR#29 CpG_2,EGFR#30 CpG_8.9.10.11,CpG_25,CpG_40.41.42methylation of lung cancer group(25.7％±2.1％,4.6％±0.4％,2.8％±0.7％,4.40±0.4％)were low-er than the normal control(36.5％±4.6％,6.0％±0.6％,4.8％±0.9％,7.1％±0.4％),the difference was statistically signifi-cant(P＜0.05).No significant differences in the methylation levels within EGFR CpGs were associated with age,cancer differentiation,disease location,TNM stage with lung cancer(P＞0.05).The methylation level of EGFR#30 CpG_25 in the female group was signifi-cantly lower than that in the male group(P＜0.05),and the methylation level of EGFR#30 CpG_25 in the smoking group was higher than that in the non-smoking group(P＜0.05),the methylation level of EGFR#30 CpG_8.9.10.11 in the lymph node metastasis group was significantly lower than that in the non-lymph node metastasis(P＜0.01).There was no significant difference in methylation of EGFR between EGFR 19del and 21 L858R mutant subtypes.Conclusion Our findings suggest that EGFR methylation may be associated with the occurrence,development,gender,and smoking history of patients with EGFR driving gene-positive lung cancer,which may serve as a biomarker for the diagnosis and prognosis prediction of lung cancer.