Two Distinct Characteristics of Immune Microenvironment in Human Hepatocellular Carcinoma with Wnt/ß-Catenin Mutations.

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/ß-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/ß-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/ß-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/ß-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/ß-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/ß-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/ß-catenin signaling pathway.

Liver Imaging Reporting and Data System Contrast-Enhanced US Nonradiation Treatment Response Assessment Version 2024.

The American College of Radiology Liver Imaging Reporting and Data System (LI-RADS) standardizes the imaging technique, reporting lexicon, disease categorization, and management for patients with or at risk for hepatocellular carcinoma (HCC). LI-RADS encompasses HCC surveillance with US; HCC diagnosis with CT, MRI, or contrast-enhanced US (CEUS); and treatment response assessment (TRA) with CT or MRI. LI-RADS was recently expanded to include CEUS TRA after nonradiation locoregional therapy or surgical resection. This report provides an overview of LI-RADS CEUS Nonradiation TRA v2024, including a lexicon of imaging findings, techniques, and imaging criteria for posttreatment tumor viability assessment. LI-RADS CEUS Nonradiation TRA v2024 takes into consideration differences in the CEUS appearance of viable tumor and posttreatment changes within and in close proximity to a treated lesion. Due to the high sensitivity of CEUS to vascular flow, posttreatment reactive changes commonly manifest as areas of abnormal perilesional enhancement without washout, especially in the first 3 months after treatment. To improve the accuracy of CEUS for nonradiation TRA, different diagnostic criteria are used to evaluate tumor viability within and outside of the treated lesion margin. Broader criteria for intralesional enhancement increase sensitivity for tumor viability detection. Stricter criteria for perilesional enhancement limit miscategorization of posttreatment reactive changes as viable tumor. Finally, the TRA algorithm reconciles intralesional and perilesional tumor viability assessment and assigns a single LI-RADS treatment response (LR-TR) category: LR-TR nonviable, LR-TR equivocal, or LR-TR viable.

Incidence of Hyper Progressive Disease in Combination Immunotherapy and Anti-Programmed Cell Death Protein 1/Programmed Death-Ligand 1 Monotherapy for Unresectable Hepatocellular Carcinoma.

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 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% confidence interval [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.

Catalytic thiolation-depolymerization-like decomposition of oxyphenylene-type super engineering plastics via selective carbon-oxygen main chain cleavages.

As the effective use of carbon resources has become a pressing societal issue, the importance of chemical recycling of plastics has increased. The catalytic chemical decomposition for plastics is a promising approach for creating valuable products under efficient and mild conditions. Although several commodity and engineering plastics have been applied, the decompositions of stable resins composed of strong main chains such as polyamides, thermoset resins, and super engineering plastics are underdeveloped. Especially, super engineering plastics that have high heat resistance, chemical resistance, and low solubility are nearly unexplored. In addition, many super engineering plastics are composed of robust aromatic ethers, which are difficult to cleave. Herein, we report the catalytic depolymerization-like chemical decomposition of oxyphenylene-based super engineering plastics such as polyetheretherketone and polysulfone using thiols via selective carbon-oxygen main chain cleavage to form electron-deficient arenes with sulfur functional groups and bisphenols. The catalyst combination of a bulky phosphazene base P4-tBu with inorganic bases such as tripotassium phosphate enabled smooth decomposition. This method could be utilized with carbon- or glass fiber-enforced polyetheretherketone materials and a consumer resin. The sulfur functional groups in one product could be transformed to amino and sulfonium groups and fluorine by using suitable catalysts.

Achievement of Complete Response and Drug-Free Status by Atezolizumab plus Bevacizumab Combined with or without Curative Conversion in Patients with Transarterial Chemoembolization-Unsuitable, Intermediate-Stage Hepatocellular Carcinoma: A Multicenter Proof-Of-Concept Study.

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 superselective 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, superselective 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 3 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. 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.

Tips for Preparing and Practicing Thermal Ablation Therapy of Hepatocellular Carcinoma.

Thermal ablation therapy, including radiofrequency ablation (RFA) and microwave ablation (MWA), is considered the optimal locoregional treatment for unresectable early-stage hepatocellular carcinomas (HCCs). Percutaneous image-guided ablation is a minimally invasive treatment that is being increasingly performed because it achieves good clinical outcomes with a lower risk of complications. However, the physics and principles of RFA and MWA markedly differ. Although percutaneous thermal ablation under image guidance may be challenging in HCC cases with limited access or a risk of thermal injury, a number of ablative techniques, each of which may be advantageous and disadvantageous for individual cases, are available. Furthermore, even when a HCC is eligible for ablation based on tumor selection and technical factors, additional patient factors may have an impact on whether it is the appropriate treatment choice. Therefore, a basic understanding of the advantages and limitations of each ablation device and imaging guidance technique, respectively, is important. We herein provide an overview of the basic principles of tissue heating in thermal ablation, clinical and laboratory parameters for ablation therapy, preprocedural management, imaging assessments of responses, and early adverse events. We also discuss associated challenges and how they may be overcome using optimized imaging techniques.

Hydroxylation-Depolymerization of Oxyphenylene-Based Super Engineering Plastics To Regenerate Arenols.

Super engineering plastics, high-performance thermoplastic resins, show high thermal stability and mechanical strength as well as chemical resistance. On the other hand, chemical recycling for these plastics has not been developed due to their stability. This study describes depolymerization of oxyphenylene super engineering plastics via carbon-oxygen main chain cleaving hydroxylation reaction with an alkali hydroxide nucleophile. This method is conducted with cesium hydroxide as a hydroxy source and calcium hydride as a dehydration agent in 1,3-dimethyl-2-imidazolidinone, which provides hydroxylated monomers effectively. In the case of polysulfone, both 4,4'-sulfonyldiphenol (bisphenol S) and 4,4'-(propane-2,2-diyl)diphenol (bisphenol A) were obtained in high yields. Other super engineering plastics such as polyethersulfone, polyphenylsulfone, and polyetheretherketone were also applicable to this depolymerization.

Imaging Diagnosis of Various Hepatocellular Carcinoma Subtypes and Its Hypervascular Mimics: Differential Diagnosis Based on Conventional Interpretation and Artificial Intelligence.

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 adopts a combination of major features including arterial phase hyper-enhancement (APHE) and the washout pattern. Summary: Specific HCCs such as well or poorly differentiated type, subtypes including fibrolamellar or sarcomatoid and combined hepatocellular-cholangiocarcinoma do not often demonstrate APHE and washout appearance. Meanwhile, hypervascular liver metastases and hypervascular intrahepatic cholangiocarcinoma 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 research studies have demonstrated high accuracy (over 90% accuracy) for classifying lesions with typical imaging features from some hepatic lesions. The AI system has a potential to be implemented in clinical routine as decision support tools. However, for the differential diagnosis of many types of hypervascular liver lesions, further large-scale clinical validation is still 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 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 learn a large number of typical and atypical cases.

Role of ß-Catenin Activation in the Tumor Immune Microenvironment and Immunotherapy of Hepatocellular Carcinoma.

Recently, the therapeutic combination of atezolizumab and bevacizumab was widely used to treat advanced hepatocellular carcinoma (HCC). According to recent clinical trials, immune checkpoint inhibitors (ICIs) and molecular target agents are expected to be key therapeutic strategies in the future. Nonetheless, the mechanisms underlying molecular immune responses and immune evasion remain unclear. The tumor immune microenvironment plays a vital role in HCC progression. The infiltration of CD8-positive cells into tumors and the expression of immune checkpoint molecules are key factors in this immune microenvironment. Specifically, Wnt/ß catenin pathway activation causes "immune exclusion", associated with poor infiltration of CD8-positive cells. Some clinical studies suggested an association between ICI resistance and ß-catenin activation in HCC. Additionally, several subclassifications of the tumor immune microenvironment were proposed. The HCC immune microenvironment can be broadly divided into inflamed class and non-inflamed class, with several subclasses. ß-catenin mutations are important factors in immune subclasses; this may be useful when considering therapeutic strategies as ß-catenin activation may serve as a biomarker for ICI. Various types of ß-catenin modulators were developed. Several kinases may also be involved in the ß-catenin pathway. Therefore, combinations of ß-catenin modulators, kinase inhibitors, and ICIs may exert synergistic effects.

Non-Inflamed Tumor Microenvironment and Methylation/Downregulation of Antigen-Presenting Machineries in Cholangiocarcinoma.

Cholangiocarcinoma (CCA) is a refractory cancer; a majority of CCAs represents a non-inflamed tumor phenotype that should be resistant to treatment, including immune checkpoint inhibitors (ICIs). In this study, we aimed to understand the molecular characteristics associated with non-inflamed CCAs. The genetic/epigenetic status of 36 CCAs was obtained from the Cancer Genome Atlas (PanCancerAtlas). CCAs were classified based on immune class using hierarchical clustering analysis of gene expressions related to tumor-infiltrating lymphocytes. The associations between immune class and genetic/epigenetic events were analyzed. We found that the tumors with alterations in FGFR2 and IDH1/2 had a "non-inflamed" tumor phenotype. A significant association was observed between the non-inflamed group and the downregulation of genes involved in antigen presentation (p = 0.0015). The expression of antigen-presenting machineries was inversely correlated with their DNA methylation levels, where 33.3% of tumors had an upregulation/low-methylation pattern, and 66.7% of tumors had a downregulation/high-methylation pattern. All tumors in the "inflamed" group exhibited an upregulation/low-methylation pattern. In contrast, 24 of 30 tumors in the non-inflamed group represent the downregulation/high-methylation pattern (p = 0.0005). Methylation with downregulation of antigen-presenting machineries is associated with the "non-inflamed" tumor phenotype of CCAs. This evidence provides important insights for developing new strategies for treating CCA.

Depolymerization of robust polyetheretherketone to regenerate monomer units using sulfur reagents.

Super engineering plastics, high-performance thermoplastic resins such as polyetheretherketone, and polyphenylene sulfide have been utilized in industries, owing to their high thermal stability and mechanical strength. However, their robustness hinders their depolymerization to produce monomers and low-weight molecules. Presently, chemical recycling for most super engineering plastics remains relatively unexplored. Herein, we report the depolymerization of insoluble polyetheretherketone using sulfur nucleophiles via carbon-oxygen bond cleavages to form benzophenone dithiolate and hydroquinone. Treatment with organic halides converted only the former products to afford various dithiofunctionalized benzophenones. The depolymerization proceeded as a solid-liquid reaction in the initial phase. Therefore, this method was not affected by the shape of polyetheretherketone, e.g., pellets or films. Moreover, this depolymerization method was applicable to carbon- or glass fiber-enforced polyetheretherketone material. The depolymerized product, dithiofunctionalized benzophenones, could be converted into diiodobenzophenone, which was applicable to the polymerization.

Prognostic Factors for Overall Survival in Patients with HCV-Related HCC Undergoing Molecular Targeted Therapies: Beyond a Sustained Virological Response.

Background: The treatment of the hepatitis C virus (HCV) has reduced the risk of hepatocellular carcinoma (HCC)-related mortality. Many patients with advanced HCC have achieved longer survival through systemic chemotherapy. However, survivors of HCC may develop liver cancer during and after treatment. Therefore, the present study investigated prognostic factors for survival in patients with HCV-related HCC in the new era of molecular targeted therapy. Methods: A total of 359 patients with HCV-related HCC treated with first-line chemotherapy were reviewed. A Cox proportional hazards model and Kaplan−Meier curve were used to identify prognostic factors associated with survival outcomes. Results: The median follow-up duration was 16.0 months (range, 1.0−115.7) and the median duration of first-line systemic therapy was 3.73 months (range, 0.7−86.9). The achievement of a sustained virological response (SVR) (p < 0.001), albumin−bilirubin (ALBI) grade II/III (p < 0.001), Barcelona Clinic Liver Cancer (BCLC) stage C (p = 0.005), extrahepatic spread (p < 0.001), baseline AFP (alpha-fetoprotein) level ≥ 90 (p = 0.038), baseline DCP (des-γ-carboxy prothrombin) level ≥ 500 (p < 0.001), and a fibrosis-4 (FIB-4) index ≥ 4 (p = 0.003) were identified as prognostic factors for overall survival. Conclusions: The achievement of SVR was most strongly associated with overall survival. Other factors, such as the BCLC stage, extrahepatic spread, baseline tumor marker (AFP/DCP) levels, ALBI grade, and FIB-4 index need to be considered in the management of patients with HCV-related HCC.

Progression from early to advanced stage of immune-related cholangitis.

AIM: We report a rare case of immune-related cholangitis in which the natural course could be demonstrated. CASE PRESENTATION: Eight courses of pembrolizumab maintenance therapy were given as first-line treatment for squamous cell lung cancer; however, the patient was subsequently hospitalized due to a rapid increase in hepatobiliary enzymes. On endoscopic ultrasound, the common bile duct was dilated to 11 mm, and the wall, throughout its length from the papilla, was thickened. Endoscopic retrograde cholangiopancreatography showed no obvious stenosis in the lower bile duct; however, a parapapillary diverticulum was found, and papillary incision and bile duct plastic stent insertion were carried out. However, the liver disorder did not improve and overt jaundice appeared subsequently; therefore, an immune-related cholangitis was suspected, and prednisolone (PSL) 35 mg/day was introduced from day 59 of admission. Following PSL initiation, a decrease in serum bilirubin level was observed; however, significant decrease was not observed in alkaline phosphatase. Given the history of recurrent infectious cholangitis, magnetic resonance cholangiopancreatography was carried out on day 70 of admission. The intrahepatic bile duct showed stenosis and dilated findings, which was considered to be a factor for repeated infectious cholangitis. CONCLUSION: No previous case reports have described the changes and progression in bile duct images in immune-related adverse events. Therefore, this case is noteworthy for considering the progression of immune-related cholangitis.

Clinical implication of immune checkpoint inhibitor on the chronic hepatitis B virus infection.

AIM: The risk of hepatitis B virus (HBV) reactivation with immune checkpoint inhibitors (ICIs) is an important issue that has not yet been fully investigated. ICI is also expected to have an antiviral effect on HBV due to its immune tolerance inhibitory effect. We herein investigated the risk of HBV reactivation and the antiviral effect of ICI administration. METHODS: This study included 892 patients on ICIs between September 2014 and May 2021 at our hospital. The frequency of HBV reactivation and antiviral effects were investigated. RESULTS: Among the 892 patients who underwent ICI, 27 were hepatitis B surface antigen (HBsAg) positive. HBV reactivation was evaluated in 24 cases, among which 4.1% (1/24) had HBV reactivation. Nucleic acid analog prophylaxis was not administered to patients with reactivation. In a study of 15 cases, the amount of HBsAg decreased from baseline; 2.18 ± 0.77 log to 48 weeks later; 1.61 ± 1.38 log (p = 0.17). Forty-eight weeks after the start of ICI, disappearance of HBsAg was observed in two out of 15 cases (13.3%), and one case each with and without nucleic acid analog. CONCLUSION: In rare cases, HBsAg-positive patients may be reactivated by ICI administration. On the other hand, when ICI is administered, it is expected to have an antiviral effect on HBV due to its immune tolerance inhibitory effect, and future drug development is expected.

How Compatible Are Immune Checkpoint Inhibitors and Thermal Ablation for Liver Metastases?

Cancer immunotherapy, which reactivates the weakened immune cells of cancer patients, has achieved great success, and several immune checkpoint inhibitors (ICIs) are now available in clinical practice. Despite promising clinical outcomes, favorable responses are only observed in a fraction of patients, and resistance mechanisms, including the absence of tumor antigens, have been reported. Thermal ablation involves the induction of irreversible damage to cancer cells by localized heat and may result in the release of tumor antigens. The combination of immunotherapy and thermal ablation is an emerging therapeutic option with enhanced efficacy. Since thermal ablation-induced inflammation and increases in tumor antigens have been suggested to promote the cancer-immunity cycle, the combination of immuno-oncology (IO) therapy and thermal ablation may be mutually beneficial. In preclinical and clinical studies, the combination of ICI and thermal ablation significantly inhibited tumor growth, and synergistic antitumor effects appeared to prolong the survival of patients with secondary liver cancer. However, evidence for the efficacy of ICI monotherapy combined with thermal ablation is currently insufficient. Therefore, the clinical feasibility of immune response activation by ICI monotherapy combined with thermal ablation may be limited, and thermal ablation may be more compatible with dual ICIs (the IO-IO combination) to induce strong immune responses.

Role of phlebotomy in the treatment of liver damage related to erythropoietic porphyria.

Liver damage affects the prognosis of patients with erythropoietic protoporphyria (EPP). However, there is no radical cure for EPP patients with severe liver damage. This study aims to investigate the effectiveness of phlebotomy in patients with severe liver damage. We examined seven patients diagnosed with EPP and liver damage between 2010 and 2020. Of the 7 cases, phlebotomy was performed in 3 cases with severe hepatic disorder, and the improvement effect of hepatic disorder was observed in all cases. In addition, as an additional study, we also investigated the mechanism by which liver damage becomes more severe. Liver biopsy samples were stained with hematoxylin and eosin and immunohistochemistry was used to examine the expression of adenosine triphosphate-binding transporter G2 (ABCG2). Liver biopsies were performed in 3 of 7 patients with EPP. Of these three patients, ABCG2 expression was low in two patients, especially in the protoporphyrin (PP) deposition area. Two patients with reduced ABCG2 expression subsequently developed severe liver damage. However, the causal relationship between the decreased expression of ABCG2 and the exacerbation of liver damage has not been directly proved, and further investigation is required in the future. This study demonstrated the effectiveness of phlebotomy in EPP patients with severe liver damage.

Higher Enhancement Intrahepatic Nodules on the Hepatobiliary Phase of Gd-EOB-DTPA-Enhanced MRI as a Poor Responsive Marker of Anti-PD-1/PD-L1 Monotherapy for Unresectable Hepatocellular Carcinoma.

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/ß-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.

Accumulation of Genetic and Epigenetic Alterations in the Background Liver and Emergence of Hepatocellular Carcinoma in Patients with Non-Alcoholic Fatty Liver Disease.

The incidence of hepatocellular carcinoma (HCC) related to non-alcoholic fatty liver disease (NAFLD) is increasing worldwide. We analyzed 16 surgically resected HCC cases in which the background liver was pathologically diagnosed as NAFLD. Specimens with Brunt classification grade 3 or higher were assigned as the fibrotic progression group (n = 8), and those with grade 1 or lower were classified as the non-fibrosis progression group (n = 8). Comprehensive mutational and methylome analysis was performed in cancerous and noncancerous tissues. The target gene mutation analysis with deep sequencing revealed that CTNNB1 and TP53 mutation was observed in 37.5% and TERT promoter mutation was detected in 50% of cancerous samples. Furthermore, somatic mutations in non-cancerous samples were less frequent, but were observed regardless of the progression of fibrosis. Similarly, on cluster analysis of methylome data, status for methylation events involving non-cancerous liver was similar regardless of the progression of fibrosis. It was found that, even in cases of non-progressive fibrosis, accumulation of gene mutations and abnormal methylation within non-cancerous areas were observed. Patients with NAFLD require a rigorous liver cancer surveillance due to the high risk of HCC emergence based on the accumulation of genetic and epigenetic abnormalities, even when fibrosis is not advanced.

Immunological Microenvironment Predicts the Survival of the Patients with Hepatocellular Carcinoma Treated with Anti-PD-1 Antibody.

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 ß-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 ß-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 ß-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 ß-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/ß-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 ß-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.