RESUMO
<p><b>OBJECTIVE</b>To study the mutation patterns of epithelial growth factor receptor (EGFR) exon 18, 19 and 21 in Chinese non-small-cell lung cancers (NSCLC).</p><p><b>METHODS</b>Somatic mutation in samples of 32 cases without Iressa-treatment were compared with that in 10 volunteers blood control. The mutations were identified for the forward and reverse sequence chains for the tyrosine kinase domain of the EGFR gene, followed by DNA template abstraction and Touchdown PCR.</p><p><b>RESULTS</b>Nine types of mutation were found in sequences of 7 cases among the 32 non-small cell lung carcinoma tissues, namely, five reported mutation within exon 19, and two new heterozygous mutations, L833V and H835L within exon 21, and two intron polymorphism. These results showed a mutation rate of 9/32 (28.1%) in Chinese with NSCLC, and of 31.6% in lung adenocarcinomas.</p><p><b>CONCLUSION</b>EGFR mutation rate in Chinese with NSCLC is consistent with those of Asian women reported in the literature but new mutation points in Chinese were presented as L833V and H835L. The mutation rate is in concordance with release rate of NSCLC obtained by Gefitinib treatment in Chinese.</p>