Endobronchial ultrasound-guided fine-needle aspiration for pulmonary carcinomas genotyping: experience with 398 cases including rapid analysis in 43 cases.

BACKGROUND

Endobronchial ultrasound-guided fine-needle aspiration (EBUS-FNA) of mediastinal lymph nodes is a minimally invasive and efficient tool for both diagnosis and staging of lung cancer. EBUS-FNA also permits tumor genotyping. However this critical datum for the therapeutic management is often long to obtain for metastatic patients with short life expectancy.

METHODS

From May 2011 to December 2017, 398 lung cancer patients underwent a genetic analysis based on EBUS-FNA samples. EBUS-FNAs were performed with rapid on-site evaluation. Mutations were studied with Sanger or new generation sequencing. Forty-three cases were also tested with a fully automated real-time PCR rapid technique. abnormalities were assessed by immunohistochemistry and/or in situ hybridization.

RESULTS

A genotypic result could be obtained in 316 cases (79.4%) and in 180 of the 198 more recent cases (90.9%). Genetic abnormalities were observed in 191 cases (48.0%). Using the rapid technique, mutational status was obtained within a few hours following the histological diagnosis and on the same day of the EBUS-FNA by analyzing fresh specimens after intra-operative cytological diagnosis.

CONCLUSIONS

In term of molecular diagnosis, EBUS-FNA provides high-quality biological material similar to that of other clinical sampling methods. Furthermore, our study suggests that a rapid molecular diagnostic method could lead to a prompt and appropriate therapeutic management for many advanced stage patients.