Search

Background: Traditional tumor classifications have relied on cellular origin, pathological morphological features, gene expression profiles, and more recently, the tumor immune microenvironment. While these classifications provide valuable insights, incorporating physiological classifications focusing on liver metabolic functions may lead to new discoveries. Summary: We proposed to reclassify benign and malignant hepatocellular neoplasms based on their physiological functions such as albumin production, bile acid production, glycolysis, glycogenesis, and adipogenesis. We further demonstrated the homology between signal pathways activated by the differentiation program of the normal hepatobiliary cells and those activated by genetic abnormalities in tumors. Specifically, Wnt/β-catenin, RAS, NOTCH, and TGF-β signaling not only contribute to cell differentiation via activation of liver-enriched transcription factors but also determine the tumor traits. Examining the distinctions between hepatocellular carcinomas (HCCs) that maintain or lose metabolic functions can yield valuable insights into the drivers of biological malignancy and tumor plasticity. Key Messages: To confirm the homology between the differentiation programs of normal hepatobiliary cells, hepatocellular adenomas (HCA), and HCC we identify liver-specific functions such as catabolism and anabolism within tumors. HCCs and HCAs that have lost these metabolic functions exhibit characteristics such as dedifferentiation, resemblance to biliary cells, or increased glycolysis. Focusing on this underexplored area will likely stimulate active research into new tumor characteristics.

Introduction The impact of etiology on response to immunotherapy in advanced hepatocellular carcinoma (HCC) is being debated, with contrasting findings between early and recent post-hoc analyses of IMbrave-150 and metanalyses of clinical trials of PD-1/PD-L1 blockers. As a results, it is not clear whether the first-line systemic treatment atezolizumab plus bevacizumab is equally effective in viral and non-viral patients. Methods We retrospectively analyzed 885 HCC patients treated with first-line A + B from multiple centers from Eastern and Western countries, 53.9% having viral and 46.1% non-viral etiology. Baseline clinical and laboratory characteristics were analyzed with uni- and multi-variate models to explore potential differences on overall survival (OS), time to progression (TTP), disease control rates based on etiology and to identify putative prognostic factors in etiology subgroups. Treatment toxicities and access to second-line treatments and outcomes were also reported and compared between etiologies. Results Overall, no statistically significant differences were found in OS (mOS: viral 15.9 months; non-viral 16.3 months), TTP (mTTP: viral 8.3 months; non-viral 7.2 months), and disease control rates (DCR: viral 78.1%; non-viral 80.8%) based on etiology. Prognostic factors of survival and progression were mainly shared between viral and non-viral etiologies, including alpha-fetoprotein, aspartate transaminase, neutrophil-to-lymphocyte ratio (NLR) and ALBI score. Exploratory analyses highlighted a possible stronger association of immunological factors, i.e. NLR and eosinophil count, to treatment outcomes in viral patients. The toxicity profile, the access to and type of second-line treatments and their outcome in terms of OS almost overlap in the two etiology subgroups. Conclusion Atezolizumab plus bevacizumab efficacy does not vary according to underlying etiology of HCC in a multicenter, real-world population, matching recent post-hoc findings from the IMbrave-150 trial. Preliminary analyses suggest that some prognostic factors differ between viral and non-viral patients, potentially due to biological and immunological differences. Prospective and comparative trials stratifying by etiology are warranted to validate these findings and guide clinical practice.

Introduction: Immunotherapy is becoming a promising approach for unresectable-hepatocellular carcinoma (HCC); the anti-tumor response is affected by the tumor microenvironment (TME). Although Wnt/β-catenin mutations are reported to cause non-inflamed phenotype, their role on TME remains controversial. We aimed to clarify the heterogeneity of immunophenotype in HCC with Wnt/β-catenin mutations. Methods: This study includes 152 resected HCCs; mutations in the catenin beta-1, adenomatous polyposis coli, or AXIN1, or AXIN2 genes were defined as Wnt/β-catenin mutations. With hierarchical cluster analyses, TME was classified into inflamed or non-inflamed classes based on the gene expressions associated with T-cell activation. Expression profiles of molecules related to cell differentiation and biliary-stem cell markers were compared between the TME classes to investigate whether differences in tumor traits were associated with TME. Results: Forty of 152 (26.3%) HCCs carried the Wnt/β-catenin mutations. Of these, 33 were classified as non-inflamed (33/40, 82.5%) and 7 as inflamed (7/40, 17.5%). Non-inflamed class was characterized by low number of CD3+, CD4+, and CD8+ cells on immunostaining, and high mRNA expressions of AXIN2 and GLUL, which are involved in the canonical Wnt/β-catenin signaling and hepatocyte differentiation, respectively. Non-inflamed tumors showed higher enhancement on the hepatobiliary-phase of gadolinium-ethoxybenzyl-diethylenetriamine (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) compared to inflamed tumors. HCCs classified as inflamed class are revealed to have high numbers of CD3+, CD4+, and CD8+ tumor infiltrating lymphocytes on immunostaining. This class is associated with increased expression of anti-epithelial cell adhesion molecule and FOXM1 accompanied by upregulation of genes related to interferon-gamma signaling, dendritic cell migration, regulatory T cells, and myeloid-derived suppressor cell activation and recognized as low enhancement nodule on Gd-EOB-DTPA-enhanced MRI. Conclusion: Heterogeneity of tumor traits and TME was observed in HCC with Wnt/β-catenin mutation. The potential was indicated that tumor traits and TME are determined not only by the activation of the HNF4A but also by FOXM1, both of which are downstream transcription factor of the Wnt/β-catenin signaling pathway.

Background: Intrahepatic cholangiocarcinoma (iCCA) is often diagnosed at an advanced stage, leading to limited treatment options and a poor prognosis. So far, standard systemic therapy for advanced iCCA has been a combination of gemcitabine and cisplatin. However, recent advancements in the understanding of the molecular characteristics of iCCA have opened new possibilities for molecular-targeted therapies and immunotherapy. Summary: Reportedly, 9–36% of iCCA cases have an inflamed tumor immune microenvironment (TME) based on the immune gene expression signature, which is characterized by the presence of immune cells involved in anti-tumor immune responses. The majority of iCCA cases have a non-inflamed TME with a lack of effector T cells, rendering immune checkpoint inhibitors (ICIs) ineffective in these cases. Interestingly, alterations in the fibroblast growth factor receptor (FGFR2) gene and IDH1/2 gene mutations are often observed in the non-inflamed TME in iCCA. Several mechanisms have been reported for the role of driver mutations on the establishment of TME unique for iCCA. For example, IDH1/2 mutations, which cause an increase in DNA methylation, are associated with the downregulation and hypermethylation of antigen processing and presentation machinery, which may contribute to the establishment of a non-inflamed TME. Therefore, inhibitors targeting IDH1/2 may restore the DNA methylation and expression status of molecules involved in antigen presentation, potentially improving the efficacy of ICIs. FGFR inhibitors may also have the potential to modulate immunosuppressive TME by inhibitingthe suppressor of cytokine signaling 1 and activating the interferon-γ signaling as a consequence of inhibition of the FGFR signal. From this perspective, understanding the molecular characteristics of iCCA, including the TME and driver mutations, is essential for the effective application of ICIs and molecular-targeted therapies. Key Messages: Combination approaches that target both the tumor and immune system hold promise for improving the outcomes of patients with iCCA. Further research and clinical trials are needed to validate these approaches and optimize the treatment strategies for iCCA.

Introduction Programmed cell death protein 1 (PD-1)/ programmed death-ligand 1 (PD-L1) signaling blockade is the most effective strategy for the treatment of immune evading hepatocellular carcinoma (HCC). While immune checkpoint inhibitor (ICI) has revolutionized the concept of cancer treatment, it has also led to unexpected tumor growth. Regulatory T cells express PD-1 and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) receptors, which are proliferated and activated by antibody binding, and their ratio to CD8+ T cells is altered, which is one of the causes for hyper progressive disease (HPD). We examined the frequency of HPD in anti-PD-1/PD-L1 monotherapy and combination therapy with vascular endothelial growth factor (VEGF) antibody and anti-CTLA-4 antibodies. Methods This was a prospective and retrospective cohort study which enrolled 198 patients with unresectable HCC from January, 2015 to December, 2021 at the Kindai University Hospital. Fifty-eight patients received anti-PD-1/PD-L1 monotherapy, 119 patients combination with VEGF antibody, and 21 patients combination with anti-CTLA-4 antibody. We defined HPD as tumor growth rate (TGR) ratio ≥4, ΔTGR ≥40% and tumor growth kinetics ratio ≥4. Results The HPD rate was 10.3% (6/58) in anti-PD-1/PD-L1 monotherapy, 1.7% (2/119) in combination with VEGF antibody, and 4.8% (1/21) in combination with anti-CTLA-4 antibody (P=0.034). The odds ratio for HPD in the combined anti-CTLA-4 antibody group was 0.433 (95% CI: 0.05-3.83) when compared to the anti-PD-1/PD-L1 monotherapy group, and 2.93 (95% CI: 0.25-33.79) when compared to the combined VEGF antibody group. Conclusion The frequency of HPD in unresectable HCC compared to anti-PD-1/PD-L1 monotherapy was decreased with the combination with anti-VEGF antibody, and not increased with anti-CTLA-4 antibody. Anti-PD-1/PD-L1 combined with anti-CTLA-4 antibody is now available in real-world and needs to be further validated with accumulated clinical practice.

Introduction: Atezolizumab plus bevacizumab therapy is extremely effective in the treatment of intermediate-stage hepatocellular carcinoma (HCC), with a response rate of 44%, as reported in the IMbrave150 trial. When tumor shrinkage is obtained, achieving complete response (CR) is possible in many cases using curative conversion with resection, ablation, or super selective transarterial chemoembolization (TACE) with curative intent. This concept, i.e., curative conversion by combining systemic therapy and locoregional therapy, has not been reported before. This multicenter proof-of-concept study was conducted to show the value of curative conversion in immunotherapy-treated intermediate-stage HCC meeting TACE-unsuitable criteria. Methods: This study included 110 consecutive Child-Pugh A patients who received atezolizumab plus bevacizumab as first-line treatment for unresectable and TACE-unsuitable intermediate-stage HCC at seven centers in Japan. CR rate, drug-free rate, time to CR, change in liver function, efficacy in positron emission tomography (PET)-positive HCC, progression-free survival (PFS), and overall survival (OS) were assessed in patients who achieved CR using resection, ablation, super selective TACE with curative intent following atezolizumab plus bevacizumab or atezolizumab plus bevacizumab alone. Results: Clinical or pathological CR was achieved in 38 patients (35%) (median observation period: 21.2 months). The modalities of curative conversion in 35 patients were as follows: resection, 7; ablation, 13; and superselective TACE, 15. Three patients achieved clinical CR with atezolizumab plus bevacizumab therapy alone. Among the 38 CR patients, 25 achieved drug-free status. PFS was not reached, and three patients experienced recurrence after reaching CR. Regarding OS, there were no deaths in any of the CR patients. The albumin-bilirubin score did not deteriorate after locoregional therapy or resection. Of seven PET-positive patients who achieved CR with atezolizumab plus bevacizumab followed by curative conversion, five achieved drug-free status. Discussion/Conclusion: The achievement of CR rate by curative conversion in patients treated with atezolizumab plus bevacizumab as the preceding therapy for unresectable and TACE-unsuitable intermediate-stage HCC was 35%. Overall, 23% of patients achieved drug-free status and no recurrence was observed from this patient subgroup with CR and drug free status. Thus, achieving CR and/or drug-free status should be a therapeutic goal for patients with intermediate-stage HCC without vascular invasion or extrahepatic spread.

Background. Hepatocellular carcinoma (HCC) is unique among malignancies, and its characteristics on contrast imaging modalities allow for a highly accurate diagnosis. The radiological differentiation of focal liver lesions is playing an increasingly important role, and the Liver Imaging Reporting and Data System (LI-RADS) adopts a combination of major features including arterial phase hyperenhancement (APHE) and washout pattern. Summary. Specific HCCs such as well or poorly differentiated type, subtypes including fibrolamellar or sarcomatoid and combined hepatocellular-cholangiocarcinoma does not often demonstrate APHE and washout appearance. Meanwhile, hypervascular liver metastases and hypervascular intrahepatic cholangiocarcinoma (ICC) can demonstrate APHE and washout. There are still other hypervascular malignant liver tumors (i.e., angiosarcoma, epithelioid hemangioendothelioma) and hypervascular benign liver lesions (i.e., adenoma, focal nodular hyperplasia, angiomyolipoma, flash filling hemangioma, reactive lymphoid hyperplasia, inflammatory lesion, arterioportal shunt), which need to be distinguished from HCC. When a patient has chronic liver disease, differential diagnosis of hypervascular liver lesions can be even more complicated. Meanwhile, artificial intelligence (AI) in medicine has been widely explored, and recent advancement in the field of deep learning has provided promising performance for the analysis of medical images. Especially, radiological imaging data contain diagnostic, prognostic, and predictive information which AI can extract. The AI researches have demonstrated high accuracy (over 90% accuracy) for classifying lesions with typical imaging features from some hepatic lesions. AI system has a potential to implement in clinical routine as decision support tools. However, for the differential diagnosis of many types of hypervascular liver lesions, further large-scale clinical validation still is required. Key Messages. Clinicians should be aware of the histopathological features, imaging characteristics and differential diagnoses of hypervascular liver lesions to a precise diagnosis and the more valuable treatment plan. We need to be familiar with such atypical cases to prevent a diagnostic delay, but AI based tools also need to lean a large number of typical and atypical cases.

Background and Rationale: Immune checkpoint inhibitor (ICI) therapy is an expanding therapeutic option for hepatocellular carcinoma (HCC). Antibiotics (ATB) taken prior to or early during ICI therapy can impact immunotherapy efficacy across indications; however, the effect of ATB is undefined in HCC. Methods: In a large international cohort of 450 ICI recipients from Europe, North America, and Asia, we categorized patients according to timing of ATB focusing on exposure within −30 to +30 days from ICI (early immunotherapy period [EIOP]). EIOP was evaluated in association with overall survival (OS), progression-free survival (PFS), and best radiologic response using RECIST 1.1 criteria. Results: Our study comprised mostly cirrhotic (329, 73.3%) males (355, 79.1%) with a Child-Turcotte Pugh class of A (332, 73.9%), receiving ICI after 1 therapy line (251, 55.9%) for HCC of Barcelona clinic liver cancer stage C (325, 72.4%). EIOP (n = 170, 37.9%) was independent of baseline clinicopathologic features of HCC and correlated with longer PFS (6.1 vs. 3.7 months, log-rank p = 0.0135). EIOP+ patients had similar OS, overall response, and disease control rates (DCRs) compared to EIOP. The effect of EIOP persisted in landmark time analyses and in multivariable models, confirming the independent predictive role of EIOP in influencing PFS following adjustment for covariates reflective of tumor burden, liver function, and ICI regimen administered. In patients receiving programmed cell death-1 receptor/ligand inhibitors monotherapy, EIOP was also associated with higher DCRs (61.4% vs. 50.9%, p = 0.0494). Conclusions: Unlike other oncological indications, ATB in the 30 days before or after ICI initiation is associated with improved benefit from immunotherapy, independent of disease and treatment-related features. Evaluation of the immune microbiologic determinants of response to ICI in HCC warrants further investigation.

Introduction: Immune checkpoint inhibitors (ICIs) are promising agents for the treatment of hepatocellular carcinoma (HCC). However, the establishment of noninvasive measure that could predict the response to ICIs is challenging. This study aimed to evaluate tumor responses to ICIs using the hepatobiliary phase of gadolinium-ethoxybenzyl-diethylenetriamine (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI), which was shown to reflect Wnt/β-catenin activating mutation. Methods: A total of 68 intrahepatic HCC nodules from 18 patients with unresectable HCC and Child-Pugh class A liver function who received anti-programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1) monotherapy were enrolled in this study. All patients had viable intrahepatic lesions evaluable using the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI within the 6 months prior to the treatment. The relative enhancement ratio was calculated, and the time to nodular progression (TTnP) defined as 20% or more increase in each nodule was compared between higher or hypo-enhancement HCC nodules. Then, the progression-free survival (PFS) and objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1) were compared between patients with and without HCC nodules with higher enhancement on hepatobiliary phase images. Results: The median PFS was 2.7 (95% confidence interval [CI]: 1.4–4.0) months in patients with HCC nodules with higher enhancement (n = 8) and 5.8 (95% CI: 0.0–18.9) months in patients with hypointense HCC nodules (n = 10) (p = 0.007). The median TTnP of HCC nodules with higher enhancement (n = 23) was 1.97 (95% CI: 1.86–2.07) months and that of hypointense HCC nodules (n = 45) was not reached (p = 0.003). The ORR was 12.5% (1/8) versus 30.0% (3/10); the disease control rate was 37.5% (3/8) versus 70.0% (7/10), respectively, in patients with or without higher enhancement intrahepatic HCC nodules. Conclusion: The TTnP on HCC nodules with higher enhancement and the median PFS in patients who carried higher enhancement intrahepatic HCC nodules were significantly shorter than those in hypointense HCC nodules with anti-PD-1/PD-L1 monotherapy. The intensity of the nodule on the hepatobiliary phase of Gd-EOB-DTPA-enhanced MRI is a promising imaging biomarker for predicting unfavorable response with anti-PD-1/PD-L1 monotherapy in patients with HCC.

Introduction: Although immune checkpoint inhibitors (ICIs) have been considered as promising agents for the treatment of advanced hepatocellular carcinoma (HCC), previous clinical trials revealed that the response to anti-programmed cell death protein 1 (anti-PD-1) monotherapy was as low as 20%. Identifying subgroups that respond well to ICIs is clinically important. Here, we studied the prognostic factors for anti-PD-1 antibody treatment based on the molecular and immunological features of HCC. Methods: Patients who were administered anti-PD1 antibody for advanced HCC at Kindai University Hospital were included. Clinicopathological backgrounds and antitumor responses were examined in 34 cases where tumor tissues before treatment were available. Transcriptome analysis was performed using 40 HCC samples obtained from surgical resection, and immune status was compared between 20 HCCs with activating mutations in β-catenin and those without the mutations using transcriptome-based immunogram. Results: Univariate analysis showed that the disease control rate was significantly better in patients with α-fetoprotein < 400 ng/mL, negative for β-catenin/glutamate synthetase (GS) staining, high combined positive score (CPS) of programmed death-ligand 1 (PD-L1), and increased infiltration of CD8+ cells in tumor tissues. Among them, negative staining of β-catenin/GS, CPS of PD-L1 ≥ 1, and high degree of CD8+ tumor-infiltrating lymphocytes (TILs) were significantly associated with longer survival in both progression-free survival (PFS) and overall survival (OS). The combination of these factors well stratified the survival of the patients on anti-PD-1 antibody in both PFS and OS (p < 0.0001 and p = 0.0048 for PFS and OS, respectively). In addition, the immunogram revealed that tumor-carrying mutations in β-catenin showed downregulation of immune-related genes, especially in those related to priming and activation by dendritic cells, interferon-γ response, inhibitory molecules, and regulatory T cells. Discussion/Conclusion: The combined score including Wnt/β-catenin activation, CPS of PD-L1, and degree of CD8+ TILs in HCC is informative for predicting the response to ICI in HCC cases. Constitutive activation of β-catenin can induce an immune cold phenotype with downregulation of immune-related genes, and immunohistochemistry-based evaluation is beneficial for identifying the subgroup that shows a good response to ICI.

Background and Aim: Immune checkpoint inhibitors are promising agents for the treatment of hepatocellular carcinomas (HCC) refractory to conventional therapies. To enhance the efficacy of this treatment, immunological and molecular characteristics of HCC with programmed cell death ligand 1 (PD-L1) should be explored. Methods: Clinical backgrounds, PD-L1 expression, and the amount of CD8+ tumor-infiltrating mononuclear cells (TIMCs) were analyzed in 154 HCCs. The expression of 3 stem cell markers and co-inhibitory receptors on tumor cells and TIMCs, respectively, were examined by immunohistochemical analysis. Somatic mutations in the 409 cancer-associated genes and TERT promoter were determined; HCCs were classified based on the presence of gene alterations affecting the 8 oncogenic pathways. The results were validated using the dataset from the Cancer Genome Atlas. Results: The expression of PD-L1 in the HCCs was positively correlated with progressive tumor features, the presence of cytokeratin 19 (CK19), Sal-like protein 4 (SALL4), and the mutations of genes involving the phosphatidyl inositol 3-kinase (PI3K)-Akt pathway. Although CD8+ cells were densely infiltrated in PD-L1-positive tumors, these TIMCs frequently expressed multiple co-inhibitory receptors. However, a subset of PD-L1-positive tumors characterized by activating mutations of the PI3K-Akt pathway showed a low degree of TIMCs. Conversely, PD-L1-negative HCCs were associated with mutations in the β-catenin pathway and a small number of TIMCs, although the expression of co-inhibitory receptors was rare. Conclusions: PD-L1-positive HCCs frequently showed an inflamed phenotype with stem cell features; a subset of PD-L1-positive HCCs with mutations in the PI3K-Akt pathway showed a non-inflamed phenotype. In HCCs with dense infiltration of TIMCs, CD8+ cells expressed multiple co-inhibitory receptors, suggesting T cell exhaustion. On the other hand, PD-L1-negative HCCs showed mutations leading to β-catenin activation and exhibited a non-inflamed background. These characteristics should be taken into consideration for developing novel combination therapies using immune checkpoint inhibitors.