ESTRO 2025 - Abstract Book

S404

Clinical - Biomarkers

ESTRO 2025

10

Digital Poster Performance and Clinical Utility of Next Generation Sequencing in Head and Neck Cancer and Thyroid Cancer Pathways Ian S Boon 1,2 , Nimesh Patel 3 , Karwan Moutasim 4 1 Department of Clinical Oncology, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom. 2 Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom. 3 Department of ENT and Head and Neck Surgery, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom. 4 Department of Pathology, University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom Purpose/Objective: Cancer genomics with next generation sequencing (NGS) offers utility in improving diagnostics, prognostic, and predictive value in cancer patients (1) . Major head and neck and thyroid cancer guidelines are recommending NGS in specific indications (2), (3) .We investigated the real-world performance and impact of NGS adoption in local head and neck and thyroid cancer pathways in a tertiary cancer referral centre. Material/Methods: Patient included between January 2023 to Feb 2024. NGS performed using the Illumina TruSightOncology 500HT according to the UK National Genomic Test Directory (4) . Samples were processed within the UK NHS genomics laboratory hubs. Efficacy and throughput turnaround time were assessed. Clinical impacts were evaluated. 80 patients were included head and neck (n=53) and 27 thyroid ( n=27). 131 NGS reports were issued with quality control fail of 27% due to poor quality RNA/DNA (n=26) and insufficient quantity (n=5). Average number of days to report first authorised 13.5 days. Diagnostics NGS assisted diagnostics in 32% (17/53) head and neck cases. PLAG1 gene rearrangement (n=3) and HMGA2 (n=1) detected in pleomorphic adenoma. DICER-1 mutation (n=1) in thyroblastoma, EWSR1:ERG rearrangement(n=1) in Ewing’s sarcoma., CTNNB1 (n=2); and GNAS gene (n=1). NGS had diagnostic impact in 33% (9/27) of thyroid cases, BRAF mutation favours papillary thyroid cancer and NRAS favours NIFTP diagnosis. Prognostic value NGS added prognostic value in 29% (8/27) thyroid cases. BRAF presence indicated poorer prognostic in papillary thyroid and concurrent TERT mutation confers 40% risks of recurrence (n=1). In head and neck cancer, TP53 (n=2) indicates poorer prognosis in metastatic squamous cell cancers. Predictive value Potentially clinically actionable mutation detected in 29% of thyroid cases, BRAF(n=7) and RET (n=1). RET mutation allows the use of selpercatinib targeted therapy. No clinically actionable mutation detected in head and neck cohort. Conclusion: NGS provided clinical utility impacting diagnostics in 1 of out 3 head and neck and thyroid cancer patients. In head and neck cancer, NGS offers less predictive value as compared to thyroid cancers. Timely turnaround of NGS report for clinician increasingly essential for treatment decision-making. NGS has a clear role in head and neck and thyroid cancer pathways and multi-disciplinary oncology team should familiarise with roles of NGS in patient management. Results: Performance

Keywords: head and neck, next generation sequencing, thyroid