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.
Resources from the same session
5650 - Tissue-based activation of mucosal-associated invariant T (MAIT) cells in combination ipilimumab and nivolumab checkpoint inhibitor (CI) colitis.
Presenter: Sarah Sasson
Session: Poster Display session 3
Resources:
Abstract
5944 - Significance of severe immune-related adverse effects (irAE) on patients with advanced tumors treated with immune checkpoint inhibitors being admitted for secondary toxicity: Clinical relevance and next steps
Presenter: Leyre Zubiri
Session: Poster Display session 3
Resources:
Abstract
5989 - Implementation of a dedicated immuno-oncology toxicity service reduces the acute impact of immune-related adverse events
Presenter: Anna Olsson-Brown
Session: Poster Display session 3
Resources:
Abstract
3267 - Cardiotoxic and pro-inflammatory effects induced by the association of immune checkpoint inhibitor Pembrolizumab and Trastuzumab in preclinical models
Presenter: Nicola Maurea
Session: Poster Display session 3
Resources:
Abstract
3417 - Interstitial lung disease associated with immune-checkpoint inhibitors in malignant diseases
Presenter: Akira Yamagata
Session: Poster Display session 3
Resources:
Abstract
2071 - A Phase 1 Study of Intraperitoneal MCY-M11 Anti-Mesothelin CAR for Women with Platinum Resistant High Grade Serous Adenocarcinoma of the Ovary, Primary Peritoneum, or Fallopian Tube, or Subjects with Peritoneal Mesothelioma with Recurrence after Prior Chemotherapy
Presenter: Christina Annunziata
Session: Poster Display session 3
Resources:
Abstract
4935 - Trial in progress: First-in-human study of a novel anti-NY-ESO-1–anti-CD3, TCR-based bispecific (IMCnyeso) as monotherapy in NY-ESO-1/LAGE-1A-positive advanced solid tumors (IMCnyeso-101)
Presenter: Juanita Lopez
Session: Poster Display session 3
Resources:
Abstract
5613 - Nimotuzumab-Cisplatin-Radiation versus Cisplatin-Radiation in HPV negative oropharyngeal cancer
Presenter: Kumar Prabhash
Session: Poster Display session 3
Resources:
Abstract
2576 - Interim analysis of a single arm phase 2 study of adjuvant nivolumab after salvage resection in head and neck squamous cell carcinoma patients previously treated with definitive therapy.
Presenter: Trisha Wise-draper
Session: Poster Display session 3
Resources:
Abstract
4758 - A Phase I Study of the CDK4/6 Inhibitor, Palbociclib in combination with Cetuximab and Intensity Modulated Radiation Therapy (IMRT) for Locally Advanced Squamous Cell Carcinoma of the Head and Neck (SCCHN); A Result of Dose Escalation Cohort
Presenter: Nuttapong Ngamphaiboon
Session: Poster Display session 3
Resources:
Abstract