Comparing the clinicopathological characteristics of combined hepatocellular-cholangiocarcinoma with those of other primary liver cancers by use of the updated World Health Organization classification.

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is an uncommon hepatic malignancy with a poor outcome. The 2019 World Health Organization (WHO) classification modified the definition and discarded the subtypes with stem cell features. However, the differences among cHCC-CCA, hepatocellular carcinoma (HCC), HCC with stem cell/progenitor features (HCCscf) and intrahepatic cholangiocarcinoma (iCCA) remain undetermined. The aim of this study was to investigate the characteristics of cHCC-CCA in comparison with those of other primary liver cancers by utilising the updated WHO classification. We retrospectively analysed 64 cHCC-CCA patients and 55 HCCscf patients from December 2007 to May 2018. Propensity score matching was conducted to compare these with HCC and iCCA patients. Clinicopathological characteristics, event-free survival and overall survival were evaluated with multivariate Cox proportional hazard regression. During a median follow-up of 55.9 months, cHCC-CCA patients had significantly poorer survival than HCCscf patients, and survival intermediate between that of HCC patients and that of iCCA patients. Hepatitis B virus (HBV) infection and high levels of tumour-infiltrating lymphocytes (TILs) were associated with favourable survival in cHCC-CCA patients. In the multivariate analysis, poor hepatic reserve, absence of HBV infection, stage IV disease and low levels of TILs were significant negative prognostic factors in cHCC-CCA patients. After being pooled with other primary liver cancers, cHCC-CCA and iCCA resulted in the worse survival. cHCC-CCA patients have survival intermediate between that of HCC patients and iCCA patients, and HBV infection and high levels of TILs predict favourable survival. Our study provides clinical correlations for the new 2019 WHO classification.

Yen CC ，Yen CJ ，Shan YS ，Lin YJ ，Liu IT ，Huang HY ，Yeh MM ，Chan SH ，Tsai HW ... -  《-》

Is nestin a diagnostic marker for combined hepatocellular-cholangiocarcinoma?

The type IV intermediate filament, nestin, may be a candidate diagnostic marker for combined hepatocellular-cholangiocarcinoma (cHCC-CCA). Therefore, the significance of nestin as a diagnostic marker for cHCC-CCA categorized by the World Health Organization (WHO) 2019 classification and its relationship with clinicopathological features were examined in the present study. Nestin expression was immunohistochemically assessed in the liver sections from 75 patients with cHCC-CCA, 22 with small duct-type intrahepatic cholangiocarcinoma (iCCA), 20 with large duct-type iCCA and 35 with hepatocellular carcinoma (HCC). Nestin expression and its relationship with clinicopathological features and genetic alterations were investigated in cHCC-CCA. Nestin expression was detected in significantly more patients with cHCC-CCA (66.7%) than in those with large duct-type iCCA (5%) (P < 0.01), HCC (2.9%) (P < 0.01) and small duct-type iCCA (40.9%) (P < 0.05). Nestin expression was partly associated with neural cell adhesion molecule (NCAM) and vimentin expression. Nestin expression was also observed in significantly more patients with small duct-type iCCA than in those with large duct-type iCCA and HCC (P < 0.01). Nestin-positive cHCC-CCA was characterized by a smaller tumour size, the more frequent presence of cholangiolocellular carcinoma (CLC) components, a higher rate of p53 overexpression and a higher rate of multiple genetic alterations (P < 0.05). Furthermore, p53 overexpression was associated with a higher histological grade and multiple genetic alterations (P < 0.05) in nestin-positive cHCC-CCA. Nestin may be a useful diagnostic marker for a specific subgroup of cHCC-CCA and small duct-type iCCA associated with CLC components, p53 mutations and multiple genetic alterations, which are related to stemness and multipotent differentiation.

Sasaki M ，Sato Y ，Nakanuma Y 《-》

The Dominant Component and Clinicopathological Characteristics of Combined Hepatocellular-cholangiocarcinoma After Radical Resection.

Combined hepatocellular cholangiocarcinoma (cHCC-CCA) is a rare subtype of primary liver carcinoma, characterized by the unequivocal presence of both hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). However, its clinicopathological characteristics have not yet been thoroughly elucidated. In particular, cholangiolocellular carcinoma (CLC) was classified as a subtype of cHCC-CCA according to the 2010 World Health Organization (WHO) classification. However, according to the 2019 WHO classification, tumors displaying histological features consistent with CLC but lacking evidence of hepatocellular differentiation should be regarded as a distinct subtype of iCCA. Nevertheless, there may be notable differences in prognosis between CLC and iCCA, indicating the necessity for refining the classification when devising clinical treatment strategies. This study aimed to determine the clinicopathological features and prognostic factors of cHCC-CCAs following radical resection. Between January 2010 and September 2020, based on the 2010 WHO classification, we retrospectively studied the clinicopathological features and prognoses of patients with cHCC-CCAs in relation to the pathological dominant classification. The patients were classified according to the pathological dominant components of cHCC-CCA as HCC-dominant (HCC-D), iCCA-dominant (iCCA-D), or CLC-dominant (CLC-D). Data of 55 patients who underwent primary radical hepatectomy for cHCC-CCA were analyzed. The prevalences of each dominant classification were HCC-D, 21 (38.2%); iCCA-D, 11 (20.0%); and CLC-D, 23 (41.8%). Multivariate analysis showed that dominant classification was an independent risk factor for recurrence and cancer-specific survival (CSS). The dominant classification of cHCC-CCA has the potential to predict recurrence and CSS.

Matsubara K ，Kobayashi T ，Tadokoro T ，Namba Y ，Fukuhara S ，Oshita KO ，Honmyo N ，Kuroda S ，Arihiro K ，Ohdan H ... -  《-》

Revealing the role of necroptosis microenvironment: FCGBP + tumor-associated macrophages drive primary liver cancer differentiation towards cHCC-CCA or iCCA.

Previous research has demonstrated that the conversion of hepatocellular carcinoma (HCC) to intrahepatic cholangiocarcinoma (iCCA) can be stimulated by manipulating the tumor microenvironment linked with necroptosis. However, the specific cells regulating the necroptosis microenvironment have not yet been identified. Additionally, further inquiry into the mechanism of how the tumor microenvironment regulates necroptosis and its impact on primary liver cancer(PLC) progression may be beneficial for precision therapy. We recruited a single-cell RNA sequencing dataset (scRNA-seq) with 34 samples from 4 HCC patients and 3 iCCA patients, and a Spatial Transcriptomic (ST) dataset including one each of HCC, iCCA, and combined hepatocellular-cholangiocarcinoma (cHCC-CCA). Quality control, dimensionality reduction and clustering were based on Seurat software (v4.2.2) process and batch effects were removed by harmony (v0.1.1) software. The pseudotime analysis (also known as cell trajectory) in the single cell dataset was performed by monocle2 software (v2.24.0). Calculation of necroptosis fraction was performed by AUCell (v1.16.0) software. Switch gene analysis was performed by geneSwitches(v0.1.0) software. Dimensionality reduction, clustering, and spatial image in ST dataset were performed by Seurat (v4.0.2). Tumor cell identification, tumor subtype characterization, and cell type deconvolution in spot were performed by SpaCET (v1.0.0) software. Immunofluorescence and immunohistochemistry experiments were used to prove our conclusions. Analysis of intercellular communication was performed using CellChat software (v1.4.0). ScRNA-seq analysis of HCC and iCCA revealed that necroptosis predominantly occurred in the myeloid cell subset, particularly in FCGBP + SPP1 + tumor-associated macrophages (TAMs), which had the highest likelihood of undergoing necroptosis. The existence of macrophages undergoing necroptosis cell death was further confirmed by immunofluorescence. Regions of HCC with poor differentiation, cHCC-CCA with more cholangiocarcinoma features, and the tumor region of iCCA shared spatial colocalization with FCGBP + macrophages, as confirmed by spatial transcriptomics, immunohistochemistry and immunofluorescence. Pseudotime analysis showed that premalignant cells could progress into two directions, one towards HCC and the other towards iCCA and cHCC-CCA. Immunofluorescence and immunohistochemistry experiments demonstrated that the number of macrophages undergoing necroptosis in cHCC-CCA was higher than in iCCA and HCC, the number of macrophages undergoing necroptosis in cHCC-CCA with cholangiocarcinoma features was more than in cHCC-CCA with hepatocellular carcinoma features. Further investigation showed that myeloid cells with the highest necroptosis score were derived from the HCC_4 case, which had a severe inflammatory background on pathological histology and was likely to progress towards iCCA and cHCC-CCA. Switchgene analysis indicated that S100A6 may play a significant role in the progression of premalignant cells towards iCCA and cHCC-CCA. Immunohistochemistry confirmed the expression of S100A6 in PLC, the more severe inflammatory background of the tumor area, the more cholangiocellular carcinoma features of the tumor area, S100A6 expression was higher. The emergence of necroptosis microenvironment was found to be significantly associated with FCGBP + SPP1 + TAMs in PLC. In the presence of necroptosis microenvironment, premalignant cells appeared to transform into iCCA or cHCC-CCA. In contrast, without a necroptosis microenvironment, premalignant cells tended to develop into HCC, exhibiting amplified stemness-related genes (SRGs) and heightened malignancy.

Wang C ，Chen C ，Hu W ，Tao L ，Chen J ... -  《-》

Component with abundant immune-related cells in combined hepatocellular cholangiocarcinoma identified by cluster analysis.

Combined hepatocellular cholangiocarcinoma (cHCC-CCA) is a heterogeneous tumor sharing histological features with hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (iCCA). The tumor immune microenvironment (TIME) of cHCC-CCA is unclear. We compared the TIME of cHCC-CCA with that of HCC and iCCA. Twenty-three patients with cHCC-CCA after hepatectomy were evaluated in this study. Twenty-three patients with iCCA and HCC were also included. iCCA was matched for size, and HCC was matched for size and hepatitis virus infection with cHCC-CCA. Immune-related cells among the iCCA-component of cHCC-CCA (C-com), HCC-component of cHCC-CCA (H-com), iCCA, and HCC were assessed using multiplex fluorescence immunohistochemistry. Among C-com, H-com, iCCA, and HCC, multiple comparisons and cluster analysis with k-nearest neighbor algorithms were performed using immunological variables. Although HCC had more T lymphocytes and lower PD-L1 expression than iCCA (P < 0.05), there were no significant differences in immunological variables between C-com and H-com. C-com tended to have more T lymphocytes than iCCA (P = 0.09), and C-com and H-com had fewer macrophages than HCC (P < 0.05). In cluster analysis, all samples were classified into two clusters: one cluster had more immune-related cells than the other, and 12 of 23 H-com and eight of 23 C-com were identified in this cluster. The TIME of C-com and H-com may be similar, and some immunological features in these components were different from those in HCC and some iCCA. Cluster analysis identified components with abundant immune-related cells in cHCC-iCCA.

Yagi N ，Suzuki T ，Mizuno S ，Kojima M ，Kudo M ，Sugimoto M ，Kobayashi S ，Gotohda N ，Ishii G ，Nakatsura T ... -  《-》