RT Journal Article SR Electronic T1 Inflamed and non-inflamed classes of HCC: a revised immunogenomic classification JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 129 OP 140 DO 10.1136/gutjnl-2021-325918 VO 72 IS 1 A1 Carla Montironi A1 Florian Castet A1 Philipp K Haber A1 Roser Pinyol A1 Miguel Torres-Martin A1 Laura Torrens A1 Agavni Mesropian A1 Huan Wang A1 Marc Puigvehi A1 Miho Maeda A1 Wei Qiang Leow A1 Elizabeth Harrod A1 Patricia Taik A1 Jigjidsuren Chinburen A1 Erdenebileg Taivanbaatar A1 Enkhbold Chinbold A1 Manel Solé Arqués A1 Michael Donovan A1 Swan Thung A1 Jaclyn Neely A1 Vincenzo Mazzaferro A1 Jeffrey Anderson A1 Sasan Roayaie A1 Myron Schwartz A1 Augusto Villanueva A1 Scott L Friedman A1 Andrew Uzilov A1 Daniela Sia A1 Josep M Llovet YR 2023 UL http://gut.bmj.com/content/72/1/129.abstract AB Objective We previously reported a characterisation of the hepatocellular carcinoma (HCC) immune contexture and described an immune-specific class. We now aim to further delineate the immunogenomic classification of HCC to incorporate features that explain responses/resistance to immunotherapy.Design We performed RNA and whole-exome sequencing, T-cell receptor (TCR)-sequencing, multiplex immunofluorescence and immunohistochemistry in a novel cohort of 240 HCC patients and validated our results in other cohorts comprising 660 patients.Results Our integrative analysis led to define: (1) the inflamed class of HCC (37%), which includes the previously reported immune subclass (22%) and a new immune-like subclass (15%) with high interferon signalling, cytolytic activity, expression of immune-effector cytokines and a more diverse T-cell repertoire. A 20-gene signature was able to capture ~90% of these tumours and is associated with response to immunotherapy. Proteins identified in liquid biopsies recapitulated the inflamed class with an area under the ROC curve (AUC) of 0.91; (2) The intermediate class, enriched in TP53 mutations (49% vs 29%, p=0.035), and chromosomal losses involving immune-related genes and; (3) the excluded class, enriched in CTNNB1 mutations (93% vs 27%, p<0.001) and PTK2 overexpression due to gene amplification and promoter hypomethylation. CTNNB1 mutations outside the excluded class led to weak activation of the Wnt-βcatenin pathway or occurred in HCCs dominated by high interferon signalling and type I antigen presenting genes.Conclusion We have characterised the immunogenomic contexture of HCC and defined inflamed and non-inflamed tumours. Two distinct CTNNB1 patterns associated with a differential role in immune evasion are described. These features may help predict immune response in HCC.Data are available in a public, open access repository. Data are available on reasonable request. The RNAseq and Whole-exome sequencing data for the primary cohort have been deposited at the European Genome-Phenome Archive (EGA), which is hosted by the European Bioinformatics Institute (EBI) and the Centre for Genomic Regulation (CRG) (Accession code EGAS00001005364). The TCRseq and any other relevant data can be obtained from the corresponding authors upon reasonable request. The data used for second cohort where the liquid-biopsy analysis was performed has been deposited at GEO with accession number GSE174570.