Objective:To investigate the diagnostic value of telomerase activity and p16 gene methylation from exfoliated cells of sputum in 55 cases of solitary nodules and of being suspected of early peripheral lung cancer(T1N0M0).Methods:The sputum specimens from 34 cases of cancer nodes and 21 cases of benign lung lesion were detected for telomerase activity and p16 gene methylation by methylation analysis.Results:The qualitative diagnosis accuracy of CT scan was 61.8%(34/55) for peripheral lung cancer.Telomerase activity was positive in 29 cases:Sensitivity was 79.4%;Specificity was 90.5%;and accuracy was 83.6%.p16 gene methylation was in 11 cases:Sensitivity was 32.4%;specificity was 100%

and veracity was 58.2%.The sensitivity was increased to 86.1% by the combination of telomerase activity and p16 gene methylatiion.Conclusion:The results suggest that combining CT scan with telomerase activity and p16 gene methylation detection in sputum for patients with lung cancer may enhance the diagnostic value of conventional cytology.It is a promising approach to early diagnosis of lung cancer and massive screening in terms of its rapidity

economy and simplicity.