RESUMO
<p><b>OBJECTIVE</b>To explore the impact of Line-1 methylation on clinical features of non-small cell lung cancer and its connection with smoking and other living habits.</p><p><b>METHODS</b>Pyrosequencing was used to determine the extent of Line-1 methylation in cancer and adjacent tissues derived from 197 patients with primary non-small cell lung cancer. Non-conditional logistic regression analysis was performed to correlate the level of Line-1 methylation with clinical features and living habits of the patients.</p><p><b>RESULTS</b>Line-1 methylation for cancer tissue and adjacent tissue has measured 68.20±11.63 and 78.90±2.09, respectively (P < 0.01), and has been associated with TNM staging, smoking history and histopathological types.</p><p><b>CONCLUSION</b>Lung cancer tissue Line-1 methylation level is closely related with clinical features and smoking. There is also a correlation between histopathological types of lung cancer and relative hypomethylation of Line-1.</p>