Oops, you're using an old version of your browser so some of the features on this page may not be displaying properly.

MINIMAL Requirements: Google Chrome 24+Mozilla Firefox 20+Internet Explorer 11Opera 15–18Apple Safari 7SeaMonkey 2.15-2.23

Poster Display session 3

5664 - Analysis of circulating tumor DNA in paired plasma and sputum samples of EGFR-mutated NSCLC patients

Date

30 Sep 2019

Session

Poster Display session 3

Topics

Translational Research

Tumour Site

Non-Small Cell Lung Cancer

Presenters

Christina Grech

Citation

Annals of Oncology (2019) 30 (suppl_5): v574-v584. 10.1093/annonc/mdz257

Authors

C. Grech1, K. Hackner2, M. Strieder2, A. Buder1, M.J. Hochmair3, M. Filipits1, P. Errhalt2

Author affiliations

  • 1 Institute Of Cancer Research, Department Of Medicine I, Comprehensive Cancer Center, Medical University of Vienna, 1090 - Vienna/AT
  • 2 Department Of Pneumology, University Hospital Krems, Karl Landsteiner University of Health Sciences, 3500 - Krems/AT
  • 3 Department Of Respiratory And Critical Care Medicine, And Ludwig Boltzmann Institute Of Copd And Respiratory Epidemiology, Otto Wagner Hospital, 1140 - Vienna/AT

Resources

Login to access the resources on OncologyPRO.

If you do not have an ESMO account, please create one for free.

Abstract 5664

Background

Liquid biopsy is a minimally invasive strategy to detect genetic alterations in non-small cell lung cancer (NSCLC) patients. In particular, it is clinically useful for the detection of the EGFR T790M resistance mutation in advanced EGFR-mutated NSCLC patients who had progressed under treatment with an EGFR-TKI. While plasma analysis is commonly performed, sputum could be another potential source for circulating tumor DNA (ctDNA) in NSCLC, which has not yet been entirely evaluated.

Methods

Paired plasma and sputum samples from 23 patients with EGFR-mutated lung adenocarcinoma were analyzed for EGFR exon 19 deletions (del19), L858R, and T790M mutations by droplet digital PCR (ddPCR). All patients had histologically confirmed lung adenocarcinoma with EGFR mutations in their initial tissue biopsy at diagnosis.

Results

Tissue genotyping at diagnosis revealed 18 patients with EGFR del19 and 5 patients with L858R mutations. Among the 18 EGFR del19-positive patients, 8 showed concordant test results in plasma and sputum (2 positive, 6 negative), 6 had del19-positive plasma samples but del19-negative sputum samples, 4 were del19 negative in plasma and del19 positive in sputum. Among 5 L8585R-positive patients, 4 had concordant test results in plasma and sputum (3 positive, 1 negative), one patient was L858R positive in the plasma sample but L858R negative in sputum. In 10 out of 23 patients the T790M mutation was assessed in paired samples, 9 showed concordant test results in plasma and sputum (3 positive, 6 negative), one patient was T790M positive only in the sputum sample.

Conclusions

Our results show a high concordance between plasma and sputum for EGFR L858R and T790M mutation testing. A lower concordance was observed for EGFR del19. Thus liquid biopsy from sputum is a promising strategy that should be further evaluated.

Clinical trial identification

GS1-EK4/479-2017, 20.07.2017 EK-18-172-0918, 08.11.2018.

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.

This site uses cookies. Some of these cookies are essential, while others help us improve your experience by providing insights into how the site is being used.

For more detailed information on the cookies we use, please check our Privacy Policy.

Customise settings
  • Necessary cookies enable core functionality. The website cannot function properly without these cookies, and you can only disable them by changing your browser preferences.