Abstract 433: Diagnostic targeted sequencing panel for hepatocellular carcinoma genomic screening

Abstract

Abstract Commercially available targeted or exome panels miss some genes and regions frequently mutated in hepatocellular carcinoma (HCC); we aim to design and benchmark an HCC-specific panel as a robust high-throughput and cost-effective panel for genomic screening in HCC. We designed an Ion AmpliSeq panel targeting all exons of 33 liver cancer protein-coding genes, recurrently mutated long non-coding RNA genes MALAT1 and NEAT1, the recurrently mutated promoter regions of TERT, WDR74, MED16 and TFPI2, as well as mutation hotspots in 7 additional cancer genes. We profiled DNA from fresh frozen tumor (FFT, n=10, median depth 1495x) and/or formalin-fixed paraffin-embedded (FFPE) tumor with low input DNA (n=36, median depth 530x), and their non-tumoral counterparts from 39 HCCs using the custom panel. We benchmarked the somatic mutations and copy number alterations (CNAs) identified against those from Illumina whole-exome sequencing (WES) of the equivalent FFT samples (median depth 112x). At least one somatic mutation was identified in 35/39 cases using the custom panel. Median of 2.5 (0-74) and 3 (0-76) mutations were identified in FFT and FFPE samples, respectively. 98% (61/62) of the mutations identified from WES of the 10 FFT samples were successfully recovered using the custom panel, with the identification of an additional 6 and 32 mutations in coding and non-coding regions, respectively. Similarly, all 104 mutations identified from WES were also found based on the analysis of our custom panel of the 36 FFPE biopsies. We identified an additional 18 and 70 somatic mutations in coding and non-coding genes, respectively, using our custom panel, including 2 CTNNB1 activating mutations. Furthermore, copy number analysis revealed high correlation (r = 0.8) in the identification of gains/ amplifications and losses/ homozygous deletions in the genes included in the custom-panel between our custom panel and the WES. Here, we develop a robust high-throughput and cost-effective tool for HCC genomic screening that allows the identification with high sensitivity and specificity of somatic mutations as well as copy number alterations in routine diagnostic tissue specimens. Citation Format: Viola Paradiso, Andrea Garofoli, Nadia Tosti, Valeria Perrina, Manuela Lanzafame, Luca Quagliata, Matthias S. Matter, Stefan Wieland, Markus H. Heim, Salvatore Piscuoglio, Charlotte K. Ng, Luigi M. Terracciano. Diagnostic targeted sequencing panel for hepatocellular carcinoma genomic screening [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 433.