Abstract: ObjectiveTo investigate telomerase activity in lung cancerand adjacent peritumoral tissues,and possible association with expression of p53,C-myc,K-ras.MethodsThitry six cases of lung cancerand adjacent peritumoral tissues,20 lung benign lesion and normal lung tissues and A549,were examined for telomerase activity by TRAP-SYBR Green assay.p53,Cmyc,K-ras were examined by immunohistochemical staining in 36 cases of lung cancer tissue specimens.ResultsEighty three point three percent lung cancer specimens,25% adjacent peritumoral tissues,15% lung benign lesion were positive for telomeras activity.Telomerase activity was negative in normal lung tissues.Telo merase activity of lung cancer did not correlate with patho logic type,tumor size and clinical stage.In 30 cases of lung cancer tissue specimens with telomerase activity,p53 was overexpression in 24 cases(80%),C-myc was overexpression in 18 cases(60%),K-ras was overexpression in 22 cases(73%).Correlation was found between telomerase activity and accumulation of p53,Cmyc and K-ras by Spearman assay,and the rank correlation coefficient respectively was 0.60,0.335,0.427,P<0.01.ConclusionQualitative analysis telo merase activity is useful in diagnosis lung neoplasms.There was correlation between telomerase activity and accumulation of p53,C-myc and K-ras in lung cancer.