Abstract 3310
Background
Circulating tumor DNA (ctDNA) is a minimally-invasive technique to profile the tumor genome in different cancers but is still underexplored in squamous cell carcinoma of the head and neck (SCCHN). Our aim was to study the relevance of mutational profiling through liquid biopsy in SCCHN.
Methods
We collected plasma cell-free DNA from 39 patients (pts) with locoregional recurrent (LR) (n = 19) and/or metastatic (M) (n = 20) SCCHN. Targeted next-generation sequencing (Illumina, HiSeq4000) was performed on a custom panel of 604 genes (median coverage 1000x). When available (n = 18), a tumor biopsy was sequenced to evaluate the concordance of somatic mutations.
Results
M SCCHN pts had a higher probability of carrying ctDNA than LR pts (70% vs 31%, p = 0.0256). When ctDNA was detected, the quantity (estimated using the median of the allele frequencies (AF) of all the somatic plasma variants) did not differ between the two groups (median 2.3% vs 2.6%, p = 0.97). The concordance between liquid and solid biopsy showed that 26% of the plasma variants (14/54) were not detected in the matched tumors, reflecting some tumor heterogeneity. Conversely, 81% of the variants (168/208) identified in the solid tumors were not detected in the plasma. In a logistic regression model, the detection of the variant in the plasma was related to the metastatic status (Odds Ratio (OR) 4.50, p = 0.012), the variant AF in the tumor (OR = 5.31, p < 0.001) and the ctDNA quantity (OR = 4.13, p < 0.001). Classification of the variant as a driver or passenger based on TCGA and COSMIC was however not relevant (OR = 1.05, p = 0.948). As expected, TP53 was the most frequently mutated gene, both in liquid and solid biopsy. Of clinical interest, the plasma of 3 pts for whom no tumor was available carried 3 different potentially actionable PIK3CA mutations, including the hotspot E545K.
Conclusions
Detection of ctDNA using targeted NGS is feasible in pts with SCCHN, essentially for metastatic disease. Liquid biopsy alone can identify potentially actionable alterations but does not reflect the full landscape of the solid tumor. Presence of a solid tumor variant in the plasma is related to the variant AF, the metastatic status and the ctDNA quantity of the sample.
Clinical trial identification
NCT02139020.
Editorial acknowledgement
Legal entity responsible for the study
Cliniques Universitaires Saint-Luc - Université Catholique de Louvain, Brussels, Belgium.
Funding
Région Wallonne, Belgium - Fondation Louvain UCLouvain.
Disclosure
R. Galot: Advisory / Consultancy: Innate Pharma; Travel / Accommodation / Expenses: Astellas; Travel / Accommodation / Expenses: Amgen. J. Machiels: Honoraria (institution), Research grant / Funding (institution), Travel / Accommodation / Expenses: Pfizer; Advisory / Consultancy, Research grant / Funding (institution): Roche; Honoraria (institution), Research grant / Funding (institution): AstraZeneca; Advisory / Consultancy, Research grant / Funding (institution): Bayer; Advisory / Consultancy: Innate Pharma; Honoraria (institution), Research grant / Funding (institution): Merck Serono; Honoraria (institution), Advisory / Consultancy, Research grant / Funding (institution): Boehringer Ingelheim; Honoraria (institution), Research grant / Funding (institution), Travel / Accommodation / Expenses: BMS; Honoraria (institution), Research grant / Funding (institution): Novartis; Honoraria (institution), Research grant / Funding (institution): Janssen; Honoraria (institution), Research grant / Funding (institution): Incyte; Research grant / Funding (institution), Travel / Accommodation / Expenses: Amgen; Research grant / Funding (institution), Travel / Accommodation / Expenses, Uncompensated advisory role: MSD; Advisory / Consultancy, Data safety monitoring board with honoraria: Debio; Advisory / Consultancy, Data safety monitoring board with honoraria: Nanobiotix; Non-remunerated activity/ies, investigator and study coordinator: EORTC. All other authors have declared no conflicts of interest.
Resources from the same session
2494 - CAR-T Nursing Education at a UK Specialist Cancer Hospital
Presenter: Rose Ellard
Session: Poster Display session 3
Resources:
Abstract
2438 - Professional Quality of Life, Perceived Stress and Psychological Resistance Levels of Oncology-Hematology Nurses and the Factors Affecting
Presenter: Tugba Pehlivan
Session: Poster Display session 3
Resources:
Abstract
3541 - Representation of cancer survivors’ preferences in policies for supportive care: Implications for oncology nursing
Presenter: Samantha Mayo
Session: Poster Display session 3
Resources:
Abstract
5093 - Vaginal moisturizing post PDR-Pulse Dose Rate Brachytherapy.
Presenter: Pilar Fernández
Session: Poster Display session 3
Resources:
Abstract
1066 - The stomized, chemo and radiotreated patient vs untreated patient: complications and comparison with data literature
Presenter: Cristoforo Ferrero
Session: Poster Display session 3
Resources:
Abstract
1724 - Evaluating the role of clinical nurse specialist
Presenter: Anita Zeneli
Session: Poster Display session 3
Resources:
Abstract
3753 - Role of the Advanced Practice Nurse (APN) in a Functional Unit for Lung cancer at the Catalan Institute of Oncology
Presenter: Isabel Brao
Session: Poster Display session 3
Resources:
Abstract
2676 - A bottom-up approach for prioritising the scientific activities of the Italian Association of Cancer Nurses (AIIAO): rationale and topic identification
Presenter: Valentina Biagioli
Session: Poster Display session 3
Resources:
Abstract
575 - Investigating quality of care for people with cancer and dementia
Presenter: Naomi Farrington
Session: Poster Display session 3
Resources:
Abstract
5578 - Two years of BRCA1 and BRCA2 somatic External Quality Assessment with Gen&tiss Tiss scheme in France
Presenter: Kelly Dufraing
Session: Poster Display session 3
Resources:
Abstract