RESUMO
<p><b>OBJECTIVE</b>To investigate gene mutations of the epidermal growth factor receptor (EGFR) and K-RAS in Chinese non-small cell lung cancers (NSCLCs).</p><p><b>METHODS</b>Mutations of exons 18, 19 and 21 of the EGFR and codons 12, 13 of the K-RAS in 101 NSCLCs were detected by PCR-amplifying and gene sequencing, and the relationship between mutations and clinical characters of NSCLCs and response to gefitinib were analyzed.</p><p><b>RESULTS</b>Overall, 26 EGFR mutations (25.7%), 3 K-RAS mutations (2.9%) were detected, and EGFR mutation frequencies in adenocarcinomas, nonsmoker and female were found to be high (44.2%, 65.7% and 48.3% respectively). Nine out of 10 gefitinib treated patients with disease control was found with EGFR mutation.</p><p><b>CONCLUSION</b>The data suggest that mutation frequency of EGFR in NSCLCs from Chinese patients is higher than that of western ethnicities, such mutations are well correlated with tumor response to gefitinib, and gefitinib is more fit for Chinese NSCLC patients.</p>