Determination of epidermal growth factor receptor gene mutation of lung cancer specimen obtained by CT-guided transthoracic needle aspiration: its clinical value

Objective: To evaluate CT-guided transthoracic needle biopsy specimens in assessing epidermal growth factor receptor (EGFR) gene mutation in lung cancer. Methods: Twenty-one patients (9 males and 12 females, with a mean age of 62 years) with advanced lung cancer were enrolled in this study. Before treatment all patients underwent CT-guided transthoracic needle biopsy of the lung tumor. The biopsy specimens were sent for histopathological study and EGFR gene mutation was determined with PCR method. A 18-gauge needle or 20-gauge needle was used for the procedures. The results were analyzed. Results: The mean largest diameter of the lung masses was 4.5 cm (ranged from 1.5 to 13 cm) on CT scans. The 18-gauge puncturing needle was used in 9 cases and the 20-gauge puncturing needle was used in 12 cases. Histological diagnoses included adenocarcinoma (n=12), squamous carcinoma (n=3), poorly differentiated carcinomas (n=5) and small cell lung cancer (n=1). EGFR mutations were detected in 10 of the 21 lung tumors (47.6%). Of 12 adenocarcinoma lesions, EGFR gene mutations were detected in 8. Among 12 females patients, EGFR gene mutations were seen in 8. Conclusion: The presence of EGFR gene mutation detected in biopsy specimens provides laboratory basis for the clinical targeted therapy with drug molecules. (authors)