Abstract 60P
Background
Using liquid-based next generation sequencing (NGS) to detect circulating tumor DNA (ctDNA) and understanding genetic profiling has become more accessible recently. However, there is still limited prospective data in Asian breast cancer patients. This study is using Guardant360 to identify the genetic landscape of patients with recurrent breast cancer (BC) and de novo stage IV metastatic BC in an Asian population and to demonstrate genetic profile changes at disease progression.
Methods
Patients with either recurrent BC or de novo stage IV BC underwent both tissue-based NGS and liquid-based NGS before systemic therapy, and had liquid-based NGS done at PD. All patients were recruited from MacKay Memorial hospital from Jan 2020 to Dec 2021. The study was suspended in Jan 2022 due to restructuring of the sponsor’s organisation. Oncomine Comprehensive Assay was used for tissue based NGS, and Guardant360 was used for liquid based NGS.
Results
There were 44 patients (age range: 37-90 years old) recruited in the study, with 55 liquid samples (44 baseline and 11 PD samples), and 46 primary tissue samples or metastatic tissue samples in total. All the 46 tissue samples and all the 55 liquid samples were successfully sequenced. Out of the 44 liquid samples prior systemic therapy, ctDNA were detected in 84% (n=37) of the samples. Among of these 37 ctDNA positive samples, 64% of them have targetable alterations detected, including PIK3CA (31.8%, n=14), BRCA2 (20.5%, n=9), BRCA1 (9.1%, n=4), ERBB2 (4.6%, n=2), ESR1 (4.6%, n=2), FGFR2 amplification (4.6%, n=2), AKT1 (2.3%, n=1), and FGFR1 amplification (2.3%, n=1). In the study, we observed that higher percentage BRCA2/BCRA1 mutation was detected by liquid biopsy. A total of 31 patients underwent liquid and tissue NGS. We observed a high concordance in ESR1 alteration with 100%. Of the 12 patients with PIK3CA mutation detected in liquid and/or tissue, 8 were detected in both tissue and liquid, 2 detected in tissue alone and 2 detected in liquid alone.
Conclusions
Liquid-based NGS can be applied in clinical practice to identified clinically important mutations in Asian patients with recurrent breast cancer (BC) and de novo stage IV metastatic BC.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
P-S. Yang.
Funding
Yonglin Foundation, Taipei, Taiwan.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
362P - Efficacy and safety of MCLA-129, an anti-EGFR/c-MET bispecific antibody, in head and neck squamous cell cancer (HNSCC)
Presenter: Irene Braña
Session: Poster Display
Resources:
Abstract
363P - Effect of financial distress and mental well-being of patients with early vs advanced oral cancer on informal caregiver's quality of life: A prospective real-world data from public health sector hospital
Presenter: Abhinav Thaduri
Session: Poster Display
Resources:
Abstract
364P - Artificial intelligence provides more accurately neck lymph nodes auto-segmentation in radiotherapy
Presenter: chiencheh Chen
Session: Poster Display
Resources:
Abstract
365P - Radiotherapy treatment outcomes and treatment compliance of nasopharyngeal cancer patients in Sabah: A retrospective analysis
Presenter: Anbarasan Anbazagan
Session: Poster Display
Resources:
Abstract
366P - Pre-treatment oral fungal microbiome and nasopharyngeal carcinoma prognosis: A population-based cohort study in southern China
Presenter: Yufeng Chen
Session: Poster Display
Resources:
Abstract
367P - Prevalence and association of sarcopenia with mortality in patients with head and neck cancer: A meta-analysis
Presenter: Claire Lim
Session: Poster Display
Resources:
Abstract
368P - Distinct gene expression profiling explored using nanostring tumor signalling 360 panel with validations in different clinical stages of oral submucous fibrosis patients: A first Indian study
Presenter: Yasasve Madhavan
Session: Poster Display
Resources:
Abstract
370P - Low-dose nivolumab with induction chemotherapy for inoperable HNSCC in 111 patients: Response rates, survival, and implications for LMICs
Presenter: Josh Thomas Georgy
Session: Poster Display
Resources:
Abstract
371P - The role of FDG-PET/CT in the assessment of response to radiation therapy in head and neck cancers: A systematic review and meta-analysis
Presenter: Felix Wijovi
Session: Poster Display
Resources:
Abstract
372P - Effectiveness of HAN-MI-RADS (head and neck molecular imaging-reporting and data system) criterion in head and neck squamous cell carcinoma post concurrent chemoradiotherapy
Presenter: Manoj Gupta
Session: Poster Display
Resources:
Abstract