An exon 19 mutation of EGFR gene in the serum circulating DNA from patients with advanced lung cancer

Objective:To analyze the incidence and profile of the exon 19 mutations of the epidermal growth factor receptor (EGFR) in patients with advanced lung cancer. Methods:The circulating DNA isolated from serum was subjected for the EGFR exon 19-specific PCR amplification and direct sequencing. Results: The wild type exon 19 of EGFR was identified in 24 cases of patients with benign pulmonary diseases. Mutations were detected in 55 cases of 130 patients with lung cancer, with the incidence of 42.3%. The mutations in exon 19 were all in frame deletion of the codon 746 to 753, consisting of 7 different types. Mutations occurred predominantly in samples of patients with adenocarcinoma and small cell lung cancer, with the incidence of 58.9% and 57.1%, respectively. The mutation was not closely related with age and gender. The profile of mutations varied among the different histological types of lung cancer and the mutation pattern in adenocarcinoma was quite different from lung squamous carcinoma,adeno-squamous carcinoma, and small cell lung cancer. Conclusion:The EGFR mutation exists in the serum circulating DNA from patients with advanced lung cancer. These mutations can be detected with suitable methods that will enable us to get a potential implication in the diagnosis and targeted therapy of this disease at late stage.