Detection of EGFR gene mutations using the wash fluid of CT-guided biopsy needle in NSCLC patients.
BACKGROUND
In this study, we examined whether epidermal growth factor receptor (EGFR) mutations were detectable using a polymerase chain reaction-based assay and wash fluid of computed tomography (CT)-guided lung biopsy needles.


METHODS
DNA was extracted from wash fluid of CT-guided biopsy needles of 53 lung tumors (as diagnosed according to the results of the CT-guided biopsies). EGFR mutations, specifically exon19 deletions and exon21 L858R mutations, were examined using a mutant-enriched polymerase chain reaction assay. We also examined the presence of EGFR mutations in 26 surgically resected tumor specimens and compared the results with those obtained for the corresponding wash fluid samples.


RESULTS
The amount of DNA obtained for the wash fluid of the CT-guided biopsy needles ranged from 35 to 2360 ng. There were no significant differences in the amount of extracted DNA according to the tumor characteristics, including tumor size and the percentage of ground glass opacity. Thirty-four of the 53 lung tumor samples were histologically diagnosed as non-small cell lung cancer (NSCLC). Exon19 deletions and exon21 L858R mutations in EGFR were detected in 4 (12%) and 13 (38%) of 34 NSCLC cases, respectively. No EGFR mutations were found in the non-NSCLC cases. The EGFR mutation status in the wash fluid samples was consistent with those obtained for all 26 corresponding surgical specimens.


CONCLUSIONS
Our results indicate that EGFR mutations can be detected using wash fluid of CT-guided biopsy needles. In this manner, the DNA genotype can be determined even in extremely small clinical specimens using highly sensitive assays.
Otani
Hiroki
H
Department of Cancer and Thoracic Surgery, Oncology and Respiratory Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Toyooka
Shinichi
S
Soh
Junichi
J
Yamamoto
Hiromasa
H
Suehisa
Hiroshi
H
Kobayashi
Naruyuki
N
Gobara
Hideo
H
Mimura
Hidefumi
H
Kiura
Katsuyuki
K
Sano
Yoshifumi
Y
Kanazawa
Susumu
S
Date
Hiroshi
H
D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000473:pathology; D016009:Chi-Square Distribution; D004252:DNA Mutational Analysis; D066246:ErbB Receptors / Q000235:genetics*; D005260:Female; D005820:Genetic Testing; D005838:Genotype; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016066:Pleural Effusion, Malignant / Q000235:genetics*; D016133:Polymerase Chain Reaction; D015641:Radiography, Interventional; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed
D066246:ErbB Receptors