A phenotypical map of disseminated hepatocellular carcinoma suggests clonal constraints in metastatic sites

Histopathology. 2019 Apr;74(5):718-730. doi: 10.1111/his.13809. Epub 2019 Feb 21.

Abstract

Aims: Access to tissue in patients with hepatocellular carcinoma (HCC) is limited compared to other malignancies, particularly at advanced stages. This has precluded a thorough characterisation of molecular drivers of HCC dissemination, particularly in relation to distant metastases. Biomarker assessment is restricted to early stages, and paired primary-metastatic comparisons between samples from the same patient are difficult.

Methods and results: We report the evaluation of 88 patients with HCC who underwent autopsy, including multiregional sampling of primary and metastatic sites totalling 230 nodules analysed. The study included morphological assessment, immunohistochemistry and mutation status of the TERT promoter, the most frequently mutated gene in HCC. We confirm a strong predilection of HCC for lung dissemination, including subclinical micrometastases (unrecognised during imaging and macroscopic examinations) in 30% of patients with disseminated disease. Size of dominant tumour nodule; multinodularity; macrovascular invasion; high histological, nuclear and architectural grades; and cellular crowding were associated with the presence of extrahepatic metastasis. Among the immunohistochemistry markers tested, metastatic nodules had significantly higher K19 and EpCAM expression than primary liver tumours. Morphological and immunohistochemical features showed that metastatic HCC could be traced back to the primary tumour, sometimes to a specific hepatic nodule.

Conclusions: This study suggests limited heterogeneity in metastatic sites compared to primary tumour sites.

Keywords: extra-hepatic metastasis; hepatocellular carcinoma; tumor heterogeneity.

MeSH terms

  • Aged
  • Autopsy
  • Biomarkers, Tumor / analysis
  • Brazil
  • Carcinoma, Hepatocellular / genetics*
  • Carcinoma, Hepatocellular / secondary*
  • Cell Differentiation
  • Cohort Studies
  • Epithelial Cell Adhesion Molecule / biosynthesis
  • Female
  • Fluorescent Antibody Technique
  • Genetic Heterogeneity*
  • Humans
  • Liver Neoplasms / genetics*
  • Liver Neoplasms / pathology*
  • Logistic Models
  • Lung Neoplasms / secondary
  • Male
  • Middle Aged
  • Mutation
  • Neoplasm Metastasis
  • Phenotype
  • Telomerase / genetics

Substances

  • Biomarkers, Tumor
  • EPCAM protein, human
  • Epithelial Cell Adhesion Molecule
  • TERT protein, human
  • Telomerase