Abstract 3663
Background
Although liquid biopsy has been reported in detecting actionable mutations, and is becoming standard of care in non-small cell lung cancer (NSCLC) under certain circumstances, the relationship between plasma mutant allele fractions (MAFs) and treatment responsiveness remains unclear.
Methods
This study enrolled 134 patients with advanced NSCLC. Tumor tissue specimens were collected after surgery, and peripheral blood samples were collected at baseline (before surgery) and during treatments. Amplification-refractory mutation system (ARMS) was performed for EGFR mutation screening in all tumor tissues. Circulating single-molecule amplification and resequencing technology (cSMART) was performed in all cfDNA samples using a panel of nine genes including EGFR. EGFR status were compared between tumor tissue and matched cfDNA samples. Moreover, the association between MAFs of EGFR mutations in cfDNA and the responsiveness to tyrosine-kinase inhibitor (TKI) treatment was analyzed.
Results
EGFR mutations were detected in 56 tumor samples (56/134, ∼41.8%) and 67 matched baseline plasma cfDNA samples (67/134, 50.0%), the concordance rate between tumor and cfDNA samples is 82.8%. Specifically, EGFR exon19 non-frameshift deletions were detected in 24 tumor tissue and 23 matched cfDNA samples (concordance rate 97.8%), EGFR p.L858R mutations were detected in 24 tumor tissue and 22 matched cfDNA samples (concordance rate 97.0%). The overall response rate (ORR) and disease control rate (DCR) for EGFR mutation positive patients (TKI sensitive mutations only) were 47.6% and 73.8%, respectively. More importantly, for TKI-treated patients with original plasma EGFR MAFs higher than 0.1% and lower than 0.1%, the ORRs were 58.6% and 23.1% (17/29 versus 3/13 patients, P = 0.047), respectively.
Conclusions
In this study we confirmed that liquid biopsy based screening is reliable for actionable somatic mutation detection. The plasma mutant allele fraction of EGFR driver mutation tend to associate with the responsiveness to TKI targeted treatment. Larger cohorts are needed to clarify the impact of plasma MAFs in predicting treatment responsiveness.
Clinical trial identification
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
4242 - HIV, HBV and HCV screening practices in oncology: a cross-sectional interregional survey
Presenter: Isabelle Poizot-Martin
Session: Poster Display session 1
Resources:
Abstract
1267 - Genetic landscape of KEAP1 and NFE2L2 mutated cancers from the AACR GENIE database
Presenter: Mark Zaki
Session: Poster Display session 1
Resources:
Abstract
878 - β-arrestin1 is involved in the Ras-induced malignant transformation
Presenter: Takashi Shibano
Session: Poster Display session 1
Resources:
Abstract
4143 - Incidence of second cancer among PLWHIV: retrospective observational study of a series of 601 patients in the French CANCERVIH network
Presenter: Jean-Philippe Spano
Session: Poster Display session 1
Resources:
Abstract
5145 - A challenging task – Identifying carcinoma of unknown primary (CUP) patients according to ESMO guidelines: the CUPISCO trial experience
Presenter: Chantal Pauli
Session: Poster Display session 1
Resources:
Abstract
1737 - Incidence and Outcome of chronic lymphocytic leukemia with Deletion 17p: An Indian experience; challenges and opportunities
Presenter: Ajay Gogia
Session: Poster Display session 1
Resources:
Abstract
2596 - Driving solo? Investigation into collaborating mutations in SDH-deficient neoplasia
Presenter: Jonathan Killian
Session: Poster Display session 1
Resources:
Abstract
1499 - The potential of a novel antiangiogenic VEGFR1-D2 binding peptide in oncology therapeutics
Presenter: Afsaneh Sadre Momtaz
Session: Poster Display session 1
Resources:
Abstract
1775 - First-in-human phase I study of TAS-117, an allosteric AKT inhibitor, in patients with advanced solid tumors
Presenter: Mayu Yunokawa
Session: Poster Display session 1
Resources:
Abstract
4584 - First-in-human study of ABBV-621 in patients (pts) with previously treated sold tumors: Dose-optimization cohorts
Presenter: Emiliano Calvo
Session: Poster Display session 1
Resources:
Abstract