Comparative genomic analysis and its prognostic impact on survival between viral hepatitis-related and non-viral hepatitis intrahepatic cholangiocarcinoma.

Abstract

4120 Background: Intrahepatic cholangiocarcinoma (IHCC) is hard-to-treat cancer with a high mortality rate worldwide. Hepatitis B virus (HBV) or hepatitis C virus (HCV) is involved in the development of IHCC, especially in Asian countries. Despite rapidly growing genomic profiling studies of IHCC in Western and Eastern populations in recent years, less on genomic heterogeneity of viral hepatitis-related and non-viral hepatitis IHCC been reported. This study aims to provide a comprehensive genomic analysis of IHCC and its prognostic value in IHCC populations with or without viral hepatitis infection. Methods: FFPE tissues from 157 patients with IHCC were subject to next-generation sequencing using the FoundationOne CDx (n = 52) or ACTOnco + comprehensive genomic profiling panels (n = 105). Genomic alterations and features, including single nucleotide variations (SNVs), short insertions and deletions (InDels), copy-number variations (CNVs), fusion genes (only FoundationOne CDx), tumor mutations burden (TMB), and microsatellite instability (MSI) status, were analyzed. The prevalence of genetic mutations and their prognostic values were compared between patients with a history of hepatitis B/C infection (BC; n = 71, 45.2%) and those without hepatitis B/C infection (NBNC; n = 79, 50.3%). Seven patients had no medical record of HBV or HCV infection. Results: The most frequently mutated genes in BC- and NBNC-related IHCC populations were TP53, KRAS, and IDH1. The genetic alternations related to PI3K/AKT/mTOR signaling pathway and copy number gain of receptor tyrosine kinase were relatively dominant in BC-related IHCC. In contrast, the Ras/Raf/MAPK pathway alterations were frequently common in NBNC-related IHCC. In addition, we investigated the correlation between commonly altered genes or pathways and overall survival (OS). Interestingly, the prognostic biomarkers in BC- and NBNC-related IHCC were significantly different. The results showed that TP53 DNA-binding domain (DBD) and TET2 mutations were associated with poor prognosis in BC-related IHCC. On the contrary, CDKN2A deletion and Ras/Raf/MAPK pathway alteration were associated with inferior prognosis in NBNC-related IHCC. However, neither the PI3K/AKT/mTOR signaling alteration nor IDH1/2 mutation affected the OS in BC- or NBNC-related IHCC. Notably, we found that SWI/ SNF complex involved in ARID1A, ARID1B, ARID2, PBRM1, and SMARCA4 alterations exhibited a beneficial prognosis in BC-related IHCC patients, which has not been discussed in previous studies. Conclusions: This study provides comparative genomic profiling between BC- and NBNC-related IHCC and shows genomic heterogeneity and different dominant prognostic biomarkers and activated signaling pathways. Different treatment strategies should be considered in these two subpopulations based on these results.