Detection of epidermal growth factor receptor in tracheal adenoid cystic carcinoma

Objective To investigate the status of epidermal growth factor receptor (EGFR) gene mutations in exon 18,19,20,and 21 in tracheal adenoid cystic carcinoma,to experimentally explore the potentiality of molecularly targeted therapy in this disease.Methods The tumor cell DNA was harvested for EGFR gene mutation detection in exon 18,19,20,and 21 by ARMS method,which was extracted from paraffin embedded bronchoscopic biopsy specimens in 36 patients with adenoid cystic carcinoma at Meitan General Hospital from 2004 to 2013.The difference of mutation rate between groups was compared using Fisher's exact probability test.P ＜0.05 was considered as statistical significance.Results The gene mutation rate of EGFR was 31％ (11/36) in the 36 paraffin embedded specimens of tracheal adenoid cystic carcinoma.Among them,14％ (5/36) expressed double mutation (deletion in exon 19 and exon 21 mutation),0％ (0/36) expressed mutation in exon 20.The EGFR gene mutation rate in stage Ⅳ group was 63％ (5/8),while 21％ (6/28) in stage Ⅱ-Ⅲ group.There was statistical significance between the two groups (P ＜0.05).Conclusions The EGFR gene mutation rate in tracheal adenoid cystic carcinoma may lie between that in lung adenocarcinoma and squamous cell carcinoma,which is slightly higher than that in squamous cell carcinoma.The EGFR mutation rate in patients with hematogenous metastatic tumors is significantly higher than that in non-metastatic individuals.Patients with advanced tracheal adenoid cystic carcinoma may benefit from EGFR-tyrosine kinase inhibitor treatment. Key words: Tracheal adenoid cystic carcinoma;  Epidermal growth factor receptor mutation;  Epidermal growth factor receptor-tyrosine kinase inhibitor