Epidermal growth factor receptor mutations in Chinese patients with adenocarcinoma of the lung

Objective:To analyze the incidence and profile of mutations in epidermal growth factor receptor(EGFR) in Chinese patients with adenocarcinoma of the lung.Methods:Sixty one cases of lung adenocarcinoma tissue were collected from Shanghai,Hangzhou,and Kunming.For each case the normal lung samples were also available.The tissue DNA was abstracted and the exons 19 to 21 in EGFR gene were subjected for PCR amplification and direct sequencing.Results:The exon 19 to 21 of EGFR gene was wildtype in all normal lung tissues detected.Mutations were found in 29 cases of 61 neoplastic samples,with the incidence of 47.5 %.Mutations were mainly detected in exon 19(16/29 cases,55.2%) and exon 21(13/29 cases,44.8 %).No mutation in exon 20 was found.There were 6 types of EGFR mutation in exon 19,resulting in the deletion of the codon 746 to 752.The mutation in exon 21 belonged to the single missense substitution in the codon 858.There was no statistically significant difference between the mutations with gender and age.However,a marked difference in the mutation profile was noticed among the patients from Kunming and Shanghai.Conclusion:The EGFR mutation is a tumor-specific somatic abnormality.Some half the Chinese lung adenocarcinomas harbor the EGFR mutations,especially in the exon 19 and 21.There is a regional difference for EGFR mutation in China.