2024 World Conference on Lung Cancer (WCLC) - Posters-P3.06D.13 Patterns of Tissue NGS Alterations are Associated with ctDNA Shedding in Non Small Cell Lung Cancer Tumors Harboring EGFR Mutations

P3.06D.13 Patterns of Tissue NGS Alterations are Associated with ctDNA Shedding in Non Small Cell Lung Cancer Tumors Harboring EGFR Mutations

Back to course

Pdf Summary

This study investigated the relationship between tumor characteristics and circulating tumor DNA (ctDNA) in patients with Non-Small Cell Lung Cancer (NSCLC) harboring EGFR mutations. The presence of detectable plasma EGFR mutations is linked to worse prognosis in NSCLC. The researchers aimed to understand if ctDNA shedding in patients is associated with specific molecular alterations in tumors and overall tumor burden.<br /><br />The retrospective study analyzed 83 patients treated at the University of Chicago with NSCLC harboring EGFR exon 19 or 21 mutations. Both tissue and liquid biopsy samples underwent Next-Generation Sequencing (NGS) to identify mutations. Liquid biopsy was analyzed using the Guardant360 assay, and tissue biopsies used the Oncoplus assay covering 168 genes.<br /><br />Patients were categorized as "concordant" if the same EGFR mutation was detected in both tissue and blood. "Shedders" referred to patients with detectable ctDNA in plasma.<br /><br />Results revealed that high tumor burden is often associated with the presence of ctDNA. There was a significant correlation between a higher number of detected mutations and concordant tumor mutations (p=0.038), suggesting aggressiveness in tumors that shed ctDNA. Additionally, a higher variant allele frequency (VAF), indicative of greater ctDNA levels, was significantly associated with larger tumor size (r=0.409, p=0.001).<br /><br />The study confirmed the connection between high tumor burden and ctDNA presence and suggested that tumors with a high mutational burden might be more likely to shed ctDNA, reflecting aggressive tumor biology. The authors propose that while the findings are promising, a larger patient cohort is necessary to validate the conclusions. The analysis emphasizes the potential of ctDNA as a non-invasive biomarker for evaluating tumor dynamics and prognosis in EGFR-mutant NSCLC.

Asset Subtitle

Anna Di Lello

Meta Tag

Speaker Anna Di Lello

Topic Pathology & Biomarkers

Keywords

Non-Small Cell Lung Cancer

EGFR mutations

circulating tumor DNA

tumor burden

liquid biopsy

Next-Generation Sequencing

Guardant360 assay

Oncoplus assay

variant allele frequency

biomarker