title: Mixed hepatocellular cholangiocarcinoma tumors: Cholangiolocellular carcinoma is a distinct molecular entity.
abstract: Mixed hepatocellular cholangiocarcinoma (HCC-CCA) is a rare and poorly understood type of primary liver cancer. We aimed to perform a comprehensive molecular characterization of this malignancy.
  
  
  
  Gene expression profiling, DNA copy number detection, and exome sequencing using formalin-fixed samples from 18 patients with mixed HCC-CCA were performed, encompassing the whole histological spectrum of the disease. Comparative genomic analysis was carried out, using independent datasets of HCC (n=164) and intrahepatic cholangiocarcinoma (iCCA) (n=149).
  
  
  
  Integrative genomic analysis of HCC-CCAs revealed that cholangiolocellular carcinoma (CLC) represents a distinct biliary-derived entity compared with the stem-cell and classical types. CLC tumors were neural cell adhesion molecule (NCAM) positive (6/6 vs. 1/12, p<0.001), chromosomally stable (mean chromosomal aberrations 5.7 vs. 14.1, p=0.008), showed significant upregulation of transforming growth factor (TGF)-β signaling and enrichment of inflammation-related and immune response signatures (p<0.001). Stem-cell tumors were characterized by spalt-like transcription factor 4 (SALL4) positivity (6/8 vs. 0/10, p<0.001), enrichment of progenitor-like signatures, activation of specific oncogenic pathways (i.e., MYC and insulin-like growth factor [IGF]), and signatures related to poor clinical outcome. In the classical type, there was a significant correlation in the copy number variation of the iCCA and HCC components, suggesting a clonal origin. Exome sequencing revealed an average of 63 non-synonymous mutations per tumor (2 mean driver mutations per tumor). Among those, TP53 was the most frequently mutated gene (6/21, 29%) in HCC-CCAs.
  
  
  
  Mixed HCC-CCA represents a heterogeneous group of tumors, with the stem-cell type characterized by features of poor prognosis, and the classical type with common lineage for HCC and iCCA components. CLC stands alone as a distinct biliary-derived entity associated with chromosomal stability and active TGF-β signaling.
  
  
  
  Molecular analysis of mixed hepatocellular cholangiocarcinoma (HCC-CCA) showed that cholangiolocellular carcinoma (CLC) is distinct and biliary in origin. It has none of the traits of hepatocellular carcinoma (HCC). However, within mixed HCC-CCA, stem-cell type tumors shared an aggressive nature and poor outcome, whereas the classic type showed a common cell lineage for both the HCC and the intrahepatic CCA component. The pathological classification of mixed HCC-CCA should be redefined because of the new molecular data provided.
authors.affiliation: Liver Cancer Translational Research Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Catalonia, Spain; Mount Sinai Liver Cancer Program, (Divisions of Liver Diseases, Hematology and Medical Oncology, Department of Medicine, Department of Pathology, Recanati Miller Transplantation Institute), Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Agrin
authors.initials: A
authors.lastname: Moeini
authors.affiliation: Mount Sinai Liver Cancer Program, (Divisions of Liver Diseases, Hematology and Medical Oncology, Department of Medicine, Department of Pathology, Recanati Miller Transplantation Institute), Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Daniela
authors.initials: D
authors.lastname: Sia
authors.affiliation: Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, USA; Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Zhongyang
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Mount Sinai Liver Cancer Program, (Divisions of Liver Diseases, Hematology and Medical Oncology, Department of Medicine, Department of Pathology, Recanati Miller Transplantation Institute), Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Genis
authors.initials: G
authors.lastname: Camprecios
authors.affiliation: Mount Sinai Liver Cancer Program, (Divisions of Liver Diseases, Hematology and Medical Oncology, Department of Medicine, Department of Pathology, Recanati Miller Transplantation Institute), Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Ashley
authors.initials: A
authors.lastname: Stueck
authors.affiliation: Liver Cancer Translational Research Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Catalonia, Spain.
authors.forename: Hui
authors.initials: H
authors.lastname: Dong
authors.affiliation: Liver Cancer Translational Research Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Catalonia, Spain.
authors.forename: Robert
authors.initials: R
authors.lastname: Montal
authors.affiliation: Liver Cancer Translational Research Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Catalonia, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Torrens
authors.affiliation: Liver Cancer Translational Research Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Catalonia, Spain.
authors.forename: Iris
authors.initials: I
authors.lastname: Martinez-Quetglas
authors.affiliation: Mount Sinai Liver Cancer Program, (Divisions of Liver Diseases, Hematology and Medical Oncology, Department of Medicine, Department of Pathology, Recanati Miller Transplantation Institute), Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: M Isabel
authors.initials: MI
authors.lastname: Fiel
authors.affiliation: Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, USA; Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Ke
authors.initials: K
authors.lastname: Hao
authors.affiliation: Mount Sinai Liver Cancer Program, (Divisions of Liver Diseases, Hematology and Medical Oncology, Department of Medicine, Department of Pathology, Recanati Miller Transplantation Institute), Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Augusto
authors.initials: A
authors.lastname: Villanueva
authors.affiliation: Mount Sinai Liver Cancer Program, (Divisions of Liver Diseases, Hematology and Medical Oncology, Department of Medicine, Department of Pathology, Recanati Miller Transplantation Institute), Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Swan N
authors.initials: SN
authors.lastname: Thung
authors.affiliation: Mount Sinai Liver Cancer Program, (Divisions of Liver Diseases, Hematology and Medical Oncology, Department of Medicine, Department of Pathology, Recanati Miller Transplantation Institute), Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA.
authors.forename: Myron E
authors.initials: ME
authors.lastname: Schwartz
authors.affiliation: Liver Cancer Translational Research Laboratory, Liver Unit, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Hospital Clínic, CIBERehd, Universitat de Barcelona, Barcelona, Catalonia, Spain; Mount Sinai Liver Cancer Program, (Divisions of Liver Diseases, Hematology and Medical Oncology, Department of Medicine, Department of Pathology, Recanati Miller Transplantation Institute), Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, USA; Institució Catalana de Recerca i Estudis Avançats, Barcelona, Catalonia, Spain. Electronic address: Josep.Llovet@mssm.edu.
authors.forename: Josep M
authors.initials: JM
authors.lastname: Llovet
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000145:classification / Q000235:genetics* / Q000473:pathology; D006528:Carcinoma, Hepatocellular / Q000145:classification / Q000235:genetics* / Q000473:pathology; D018281:Cholangiocarcinoma / Q000145:classification / Q000235:genetics* / Q000473:pathology; D043171:Chromosomal Instability; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000145:classification / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D015398:Signal Transduction; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D055815:Young Adult
chemical_list: D016212:Transforming Growth Factor beta
keywords: Liver cancer; Molecular subclass; Progenitor-like origin; TGF-β signaling