Abstract 168P
Background
Routine genomic profiling in metastasic solid tumors has an impact on survival by selecting targeted therapies and montoring treatment response. Moreover, feasibility and efficiency of liquid biopsy (LB) in pancreatic cancer has been studied as tissue is not always available in these tumors given the frequent lack of tissue in these tumors.
Methods
We present an ambispective observational study in patients with locally advanced or metastatic pancreatic cancer who underwent LB before starting chemotherapy. The primary end point was to determine the prevalence of pathological molecular alterations in circulating tumor DNA (ctDNA) and their concordance with next generation sequencing in tumor tissue (TNGS). A secondary end point was the study of circulating tumor cells (CTCs) as a poor prognostic factor for survival.
Results
A total of 30 patients were included between May 2020 and September 2022. Women were 53.3% of them, and the median age was 65.5 years (37-85). At the time of LB, 86.7% had metastatic disease, 6.7% had stage III, and 6.7% had stage II. 83.4% were about to initiate a first-line chemotherapy. 86.7% of the patients had also undergone TNGS. In both LB and TNGS, one or more molecular alterations were found in 80% of patients. Fourteen different molecular alterations were found in LB, with the most prevalent mutations in TP53 (56.6%), KRAS (53.3%), ERBB2 (16.6%), MET (4%), and EGFR (4%). In TNGS, 12 alterations were found, with the most prevalent being TP53 (46.6%), KRAS (60%), MET (23.3%), and EGFR (13.3%). The concordance rate between BL and TNGS was > 70%. The median overall survival (OS) was 5.5 months (95%CI:3.6-7.4). In patients without CTCs, the OS was 6.3 months (95%CI:4.7-8.0), while patients with CTCs had an OS of 3.6 months (95%CI:1.6-5.6).
Conclusions
80% of patients presented molecular alterations in both LB and TNGS with a matching rate > 70%. The most prevalent mutations were TP53, KRAS, MET, EGFR and ERBBE in the two analyses. The presence of CTCs is a poor prognostic factor.
Editorial acknowledgement
Clinical trial identification
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
103P - MSI detection by NGS using tumor samples and liquid biopsy for patients with solid tumors: A single institution experience
Presenter: Alexandra Lebedeva
Session: Cocktail & Poster Display session
Resources:
Abstract
104P - Hypomethylated immune gene promoters as potential biomarkers in oral and oropharyngeal cancer
Presenter: Petra Anić
Session: Cocktail & Poster Display session
Resources:
Abstract
105P - Implementation of technical improvements in cfMeDIP-Seq library preparation
Presenter: Martina Dameri
Session: Cocktail & Poster Display session
Resources:
Abstract
106P - Clinical application of next-generation sequencing in metastatic colorectal cancer (mCRC): Experience from a comprehensive cancer centre
Presenter: David Lluís Garulo
Session: Cocktail & Poster Display session
Resources:
Abstract
107P - Unveiling mismatch repair deficiency (dMMR) and microsatellite-instability high (MSI-H) detection in cancer patients (pt) using a next-generation sequencing (NGS)-based molecular pre-screening program (MPP)
Presenter: Lucia Notario Rincon
Session: Cocktail & Poster Display session
Resources:
Abstract
108P - Validation and implementation of a large NGS panel to test liquid biopsies from patients with suspected advanced non-small cell lung cancer (NSCLC) in an NHS genomic laboratory for the QuicDNA biomarker study
Presenter: Rachel Dodds
Session: Cocktail & Poster Display session
Resources:
Abstract
109P - A multiomic, single-cell measurable residual disease (scMRD) assay for phasing DNA mutations and surface immunophenotypes
Presenter: Simone Formisano
Session: Cocktail & Poster Display session
Resources:
Abstract
110P - Multicellular three-dimensional tumor spheroid of nasopharyngeal carcinoma
Presenter: Shiau Chuen Cheah
Session: Cocktail & Poster Display session
Resources:
Abstract
111P - Development of digital PCR for accurate measurement of HER2 amplification in 184 gastric cancer patients
Presenter: So Young Kang
Session: Cocktail & Poster Display session
Resources:
Abstract
112P - A novel methylation-sensitive assay for early detection of hepatocellular carcinoma to improve surveillance
Presenter: Jeong Sil Ha
Session: Cocktail & Poster Display session
Resources:
Abstract