Virtual Library
Start Your Search
In Ae Kim
Author of
-
+
P2.01 - Advanced NSCLC (Not CME Accredited Session) (ID 950)
- Event: WCLC 2018
- Type: Poster Viewing in the Exhibit Hall
- Track:
- Presentations: 1
- Moderators:
- Coordinates: 9/25/2018, 16:45 - 18:00, Exhibit Hall
-
+
P2.01-62 - Extracellular Vesicle-Based Egfr Genotyping in Bronchoalveolar Lavage Fluid from Non-Small Cell Lung Cancer Patients (ID 13435)
16:45 - 18:00 | Author(s): In Ae Kim
- Abstract
Background
Liquid biopsies for EGFR genotyping using plasma cell-free DNA (cfDNA) have limited value due to low sensitivity. Extracellular vesicles (EV) have been proven to contain mutant EGFR DNA in bronchoalveolar lavage fluid (BALF) from non-small cell lung cancer (NSCLC) patients. As an alternative to plasma liquid biopsies using cfDNA, we investigated the feasibility of EV-based liquid biopsy for EGFR genotyping using BALF from NSCLC patients, prospectively.
a9ded1e5ce5d75814730bb4caaf49419 Method
EV DNA was extracted from the BALF of NSCLC patients with confirmed tissue/cytology-based EGFR genotyping at initial diagnostic work-up stage. (N=137) The number of patients with stage I, II, III, and IV are 37 (27%), 6 (4.4%), 23 (16.8%), 71 (51.8%), respectively. The patients were selected by favorable demographic data for EGFR mutation. EGFR mutation testing was done by peptide nucleic acid (PNA) clamping-assisted fluorescence melting curve analysis.
4c3880bb027f159e801041b1021e88e8 Result
The overall sensitivity and specificity of EGFR genotyping using BALF EV DNA were 69.5% and 83.3% and the concordance rate was 77.4%. (Kappa=0.534, P=0.000) The sensitivity was significantly increased along with the stage (42.1% in stage I, II, 60.0% in stage III, and 100% in stage IV). Especially, in stage IV disease, BALF EV-based EGFR typing did not miss all of tissue-proven 30 EGFR mutant cases and detected 9 additional mutant cases. Detection of EGFR mutation becomes significantly more sensitive as T stage increases. (T1 = 43.8%, T2 = 75%, T3 and T4 = 100%) Turn-around time (TAT) for EGFR genotyping using BALF EV DNA was 1-2 days, while it takes usually 2 weeks for tissue typing.
8eea62084ca7e541d918e823422bd82e Conclusion
BALF EV-based EGFR genotyping is a novel and highly promising method with rapid TAT and incredible accuracy in stage IV NSCLC patients. Further research in early stage disease is necessary and the matter of over-detection should be clinically validated by evaluating EGFR-TKI drug response.
6f8b794f3246b0c1e1780bb4d4d5dc53