Purpose Cytological endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) specimens of mediastinal
lymph node metastasis are frequently used to perform concomitant diagnosis, staging and genetic testing in non-smallcell
lung cancer (NSCLC). The purposes of this single-center retrospective study were to evaluate EBUS-TBNA samples’
adequacy for molecular testing of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK), and to
analyze the concordance between the cell block method and liquid-based cytology (LBC) in appraising the sample cellularity
and in detecting EGFR mutation.
Materials and Methods We retrospectively examined 82 patients who underwent EBUS-TBNA from October 2012 to September
2015 and received a confirmed diagnosis of lymph node metastasis of lung adenocarcinoma. Each sample was
processed using both cell block and LBC to carry out DNA analysis (adequacy criterion: tumor cell percentage > 25%) and
EGFR mutation testing.
Results Fifty-four patients were male, 66 were current or former-smokers, and the median age was 67 years. The median
size of sampled lymph nodes was 14.8 mm. Seventy-one and 66 samples were adequate to perform cell block and LBC,
respectively. The κ-statistic (0.78) showed an excellent concordance. EGFR mutation was detected in eight patients using cell
block and in seven using LBC, with a simple percentage agreement of 87.5%. ALK translocation was found in two patients.
Conclusions This study demonstrates the feasibility of EGFR mutation analysis with both cell block and LBC, with an excellent
concordance between the two methods. Considering that the majority of advanced NSCLCs are diagnosed on cytology
specimens, LBC is feasible and needs to be implemented for ancillary tests (immunocytochemistry, molecular analysis).
- Aged, 80 and over
- Anaplastic Lymphoma Kinase
- Carcinoma, Non-Small-Cell Lung
- ErbB Receptors
- Lung Neoplasms
- Lymphatic Metastasis
- Middle Aged
- Retrospective Studies