Polyploidy Spectrum Correlates with Immunophenotype and Shapes Hepatocellular Carcinoma Recurrence Following Liver Transplantation

PURPOSE: Patients receiving liver transplantation (LT) for hepatocellular carcinoma (HCC) are at high risk of tumor recurrence. Polyploidy is a fascinating characteristic of the liver and correlates with HCC development and progression. This study aims to investigate the association between hepatocyte polyploidy spectrum and HCC recurrence after LT. PATIENTS AND METHODS: Thirty-two paired HCC, peritumoral, cirrhotic, and normal liver specimens were employed to examine the hepatocyte polyploidization pattern during liver tumorigenesis. Clinicopathological implications of polyploidy spectrum for LT recipients with HCC were investigated in 205 patients from two transplant centers. Immunofluorescence staining was performed on paraffin-embedded tissue sections to determine the ploidy profiles in situ. Expression levels of CD4, CD8, forkhead box protein 3 (Foxp3) and programmed death-ligand 1 (PD-L1) were measured using immunohistochemistry. An array-based multiplex ELISA system was used for the quantitative measurement of 40 unique inflammatory cytokines. RESULTS: The fraction of mononuclear polyploidy increased, whereas that of binuclear polyploidy reduced during hepatocarcinogenesis. Recipients with highly mononuclear polyploid HCC (HMP–HCC) had inferior recurrence-free survival and HCC-specific survival than poorly mononuclear polyploid HCC recipients. These two groups differed in abundance of infiltrative CD8(+) cytotoxic T cells and FoxP3(+) Treg cells, and PD-L1 expression, as well as circulating granulocyte–macrophage colony-stimulating factor, interferon-γ and interleukin-10 levels. HMP–HCC constituted an independent recurrence predictor and could improve the discriminative efficacy of clinical prediction models (Milan criteria, AFP model, and Metroticket 2.0 criteria). A scoring system incorporating the ploidy signature was developed and validated, allowing for an improved risk prediction relative to the RETREAT score and post-MORAL score. CONCLUSION: Polyploid spectra are associated with tumor immunophenotype and provide supplementary prognostic information in LT for HCC.