Anti-integrin αvβ6 autoantibodies in patients with primary sclerosing cholangitis

BACKGROUND

Patients with primary sclerosing cholangitis (PSC) possess autoantibodies against biliary epithelial cells. However, the target molecules remain unknown.

METHODS

The sera of patients with PSC and controls were subjected to enzyme-linked immunosorbent assays to detect autoantibodies using recombinant integrin proteins. Integrin αvβ6 expression in the bile duct tissues was examined using immunofluorescence. The blocking activity of the autoantibodies was examined using solid-phase binding assays.

RESULTS

Anti-integrin αvβ6 antibodies were detected in 49/55 (89.1%) patients with PSC and 5/150 (3.3%) controls (P < 0.001), with a sensitivity and specificity of 89.1% and 96.7%, respectively, for PSC diagnosis. When focusing on the presence or absence of IBD, the proportion of the positive antibodies in PSC with IBD was 97.2% (35/36) and that in PSC alone was 73.7% (14/19) (P = 0.008). Integrin αvβ6 was expressed in bile duct epithelial cells. Immunoglobulin (Ig)G from 15/33 patients with PSC blocked integrin αvβ6-fibronectin binding through an RGD (Arg-Gly-Asp) tripeptide motif.

CONCLUSIONS

Autoantibodies against integrin αvβ6 were detected in most patients with PSC; anti-integrin αvβ6 antibody may serve as a potential diagnostic biomarker for PSC.

Ultrasound-guided polidocanol foam sclerotherapy for symptomatic giant hepatic cyst: A single-center experience

AIM

Simple hepatic cysts are typically benign; however, when they are large and symptomatic, therapeutic intervention is required. We previously reported our initial experience with ultrasound (US)-guided polidocanol foam sclerotherapy in three patients with symptomatic giant hepatic cysts. In the present study, we examined the efficacy and safety of polidocanol foam sclerotherapy in a larger number of patients with long-term follow-up.

METHODS

Between May 2016 and April 2021, 15 patients with symptomatic giant hepatic cysts were referred to our hospital. All patients were prospectively included in the study and underwent US-guided polidocanol foam sclerotherapy.

RESULTS

The mean maximum diameter and estimated cyst volume were 128.4 mm (77-223 mm) and 922.3 ml (123.2-2797 ml), respectively. Polidocanol foam was successfully administered through an 8.5-Fr pigtail catheter in all patients. The percentages of cyst diameter/volume after 1-3 months, 3-6 months, 6 months-1 year, 1-2 years, and 2-4 years of sclerotherapy were 66.8%/36.5%, 48.1%/14.8%, 34.1%/6.9%, 28.2%/3.7%, and 26.2%/3.1%, respectively. During the follow-up period, there were no cases of symptom recurrence or need for additional treatment due to cyst re-growth. Six patients (40%) had fever, one had nausea, and one had right-sided chest pain, but none of these adverse events required prolonged hospitalization or readmission.

CONCLUSIONS

US-guided polidocanol foam sclerotherapy may be an effective and safe method for the treatment of symptomatic giant hepatic cysts.

Clinical and Molecular Basis of Hepatocellular Carcinoma after Hepatitis C Virus Eradication

Hepatocellular carcinoma (HCC) arises in the background of chronic liver diseases, including hepatitis and liver cirrhosis caused by hepatitis C virus (HCV) infection. It is well known that HCV eradication using antiviral drugs can efficiently inhibit hepatocarcinogenesis. Recent advances in and development of direct-acting antiviral (DAA) drugs has revolutionized the treatment of HCV infection, and the vast majority of HCV patients can achieve HCV eradication using DAAs. However, mounting evidence clearly indicates that HCC inevitably occurs in a subset of patients after successful viral eradication using DAA therapy. Cancer is a genetic disease, and the accumulation of genetic and epigenetic aberrations may cause hepatocarcinogenesis in chronically damaged liver, even after virus elimination. In this review, we highlight HCC development after HCV eradication and discuss the current understanding of the molecular mechanisms of tumorigenesis after virus elimination, focusing on the genetic and epigenetic background of chronically damaged liver tissues.

Expansion of gastric intestinal metaplasia with copy number aberrations contributes to field cancerization

Intestinal metaplasia (IM) is a risk factor for gastric cancer following infection with Helicobacter pylori. To explore the susceptibility of pure gastric IM to cancer development, we investigated genetic alterations in single IM gastric glands. We isolated 50 single IM or non-IM glands from the inflamed gastric mucosa of 11 patients with intramucosal gastric carcinoma (IGC) and 4 patients without IGC; nineteen single glands in the non-inflamed gastric mucosa of 11 individuals from our cohort and previous dataset were also included as controls. Whole exome sequencing of single glands revealed significantly higher accumulation of somatic mutations in various genes within IM glands compared with non-IM glands. Clonal ordering analysis showed that IM glands expanded to form clusters with shared mutations. Additionally, targeted-capture deep sequencing and copy number (CN) analyses were performed in 96 clustered IM or non-IM gastric glands from 26 patients with IGC. CN analyses were also performed on 41 IGC samples and the Cancer Genome Atlas-Stomach Adenocarcinoma datasets. These analyses revealed that polyclonally expanded IM commonly acquired copy number aberrations (CNA), including amplification of chromosomes 8, 20, and 2. A large portion of clustered IM glands typically consisted of common CNAs rather than other cancer-related mutations. Moreover, the CNA patterns of clustered IM glands were similar to those of IGC, indicative of precancerous conditions. Taken together, these findings suggest that, in the gastric mucosa inflamed with H. pylori infection, IM glands expand via acquisition of CNAs comparable to those of IGC, contributing to field cancerization.

Genetic Landscape of Multistep Hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is a major cause of cancer-related death worldwide. Although several targeted therapy agents are available for advanced HCC, their antitumor efficacy remains limited. As the complex genetic landscape of HCC would compromise the antitumor efficacy of targeted therapy, a deeper understanding of the genetic landscape of hepatocarcinogenesis is necessary. Recent comprehensive genetic analyses have revealed the driver genes of HCC, which accumulate during the multistage process of hepatocarcinogenesis, facilitating HCC genetic heterogeneity. In addition, as early genetic changes may represent key therapeutic targets, the genetic landscapes of early HCC and precancerous liver tissues have been characterized in recent years, in parallel with the advancement of next-generation sequencing analysis. In this review article, we first summarize the landscape of the liver cancer genome and its intratumor heterogeneity. We then introduce recent insight on early genetic alterations in hepatocarcinogenesis, especially those in early HCC and noncancerous liver tissues. Finally, we summarize the multistep accumulation of genetic aberrations throughout cancer progression and discuss the future perspective towards the clinical application of this genetic information.

Does immune checkpoint inhibitor exhibit limited efficacy against non-viral hepatocellular carcinoma?: A review of clinical trials

Immunotherapy with immune checkpoint inhibitors has been shown to be beneficial for cancers originating from various organs. In May 2020, combination therapy with anti-programmed death-ligand 1 antibody atezolizumab and anti-vascular endothelial growth factor (VEGF) antibody bevacizumab was approved as a novel first-line systemic therapy for hepatocellular carcinoma (HCC). The number of patients with HCC not caused by hepatitis virus infection (non-viral HCC), including non-alcoholic steatohepatitis (NASH)-related HCC, has been increasing in recent years. Recently, Pfister and colleagues reported that immune checkpoint inhibitors may exhibit limited efficacy against NASH-related HCC, based on basic research and clinical data. This review will discuss the mechanism of impaired tumor immune surveillance in NASH and analyze the results of previously published clinical trials of immune checkpoint inhibitors to investigate whether patients with non-viral HCC are less likely to benefit from immunotherapy with immune checkpoint inhibitors. Furthermore, we also discuss the possibility of enhancing the therapeutic effect of immune checkpoint inhibitors for NASH-related HCC by combining anti-VEGF agents.

Pretreatment Neutrophil-to-Lymphocyte Ratio as a Predictive Marker of Response to Atezolizumab Plus Bevacizumab for Hepatocellular Carcinoma

Background: Combination therapy with anti-programmed death-ligand 1 monoclonal antibody atezolizumab plus anti-vascular endothelial growth factor agent bevacizumab (Atezo/Bev) was approved in 2020 as a first-line treatment for unresectable hepatocellular carcinoma (HCC). Atezo/Bev therapy is relatively well tolerated; however, factors that can predict its response have not yet been reported. Thus, we aimed to investigate whether the pretreatment neutrophil-to-lymphocyte ratio (NLR) could predict the therapeutic response in patients with HCC treated with Atezo/Bev therapy. Methods: We analyzed the course of 40 patients with HCC who received Atezo/Bev therapy at our hospital and attempted to identify pretreatment factors that could predict response by comparing those who achieved disease control with those who did not. Results: The pretreatment NLR value in patients who achieved disease control was significantly lower than that in patients with disease progression (2.47 vs. 4.48, p = 0.013). Using the optimal NLR cut-off value for predicting response (3.21) determined by receiver operating characteristic curve analysis, patients with NLR ≤ 3.21 had significantly better progression-free survival than those with NLR > 3.21 (p < 0.0001), although there were no significant differences in liver function or tumor-related background factors between the two groups. Conclusions: The pretreatment NLR value may be a useful predictor of response to Atezo/Bev therapy for HCC.

A simplified method to quantitatively predict the effect of lenvatinib on hepatocellular carcinoma using contrast-enhanced ultrasound with perfluorobutane microbubbles

Contrast-enhanced computed tomography (CECT) is generally used to evaluate the response to treatment of hepatocellular carcinoma (HCC); however, CECT is unsuitable for the early prediction of therapeutic effects and frequent monitoring. We aimed to investigate the usefulness of our simplified method for the quantification of tumor vascularity using contrast-enhanced ultrasound (CEUS) with perfluorobutane microbubbles [Sonazoid^® (GE Healthcare, Oslo, Norway)] to predict the therapeutic effect of lenvatinib. Among the 13 patients studied, nine who had more than a 20% reduction in tumor vascularity within 2 weeks of starting treatment experienced complete response or partial response at 8-12 weeks as assessed by CECT. In contrast, three patients without reductions and one patient with only a slight decrease in tumor vascularity had a poor response to lenvatinib. Quantitative assessment of tumor vascularity by our simplified CEUS-based method could be a useful predictor of therapeutic responses to lenvatinib in patients with HCC.

Mac-2 binding protein glycosylation isomer predicts tolerability and clinical outcome of lenvatinib therapy for hepatocellular carcinoma

BACKGROUND

Many patients with hepatocellular carcinoma present with impaired hepatic function, which often requires interruption or withdrawal of lenvatinib due to associated adverse events. We aimed to identify pre-treatment predictors of tolerability and clinical outcome of lenvatinib therapy.

METHODS

Eighty patients who received lenvatinib at our institution between 2018 and 2020 were included in this study. We assessed essential factors associated with prolonged progression-free survival (PFS), using Cox proportional hazards model. We also investigated the correlation between the factor identified as contributing most to PFS and the relative dose intensity (RDI), response rate, and duration of treatment with lenvatinib.

RESULTS

Pre-treatment level of Mac-2-binding protein glycosylation isomer (M2BPGi) showed significant association with PFS (hazard ratio = 0.52, P = .0358). Low M2BPGi levels (<1.5) correlated significantly with longer PFS than higher levels (P = .0003). Patients with M2BPGi <1.5 achieved significantly higher RDI, objective response rate, and disease control rate, and maintained lenvatinib treatment for longer than those with baseline values ≥1.5. Patients with M2BPGi ≥1.5 had a higher incidence of adverse events such as fatigue and anorexia.

CONCLUSIONS

Baseline M2BPGi levels may predict the tolerability and treatment response to lenvatinib. Patients with high M2BPGi levels may less likely to benefit from lenvatinib therapy.

Laparoscopic liver resection versus percutaneous radiofrequency ablation for small hepatocellular carcinoma

BACKGROUND

Laparoscopic liver resection (LLR) and radiofrequency ablation (RFA) play central roles to treat early-stage hepatocellular carcinoma (HCC, ≤3 cm, 1-3 nodules, and no macrovascular involvement), although data are lacking regarding whether LLR or RFA is preferable. This study aimed to compare outcomes of both treatments for small HCCs.

METHODS

Treatment outcomes of small HCCs were compared between all the minor LLRs performed between 2005 and 2016 and RFAs performed between 2011 and 2016 at Kyoto University.

RESULTS

A total of 85 and 136 patients underwent LLR and RFA, respectively. Patients that underwent LLR had higher incidence of blood transfusions, complications, and longer hospital stay. Overall and disease-specific survival rates were similar between LLR and RFA; however, recurrence-free (49.2% vs. 22.1% at 3-year) and local recurrence-free survival rates (94.9% vs. 63.6% at 3-year) were higher after LLR. Multivariate analyses identified that multiple nodules and 65-year-old and above are predictors of disease-specific survival, and that RFA is a predictor of recurrence and local recurrence.

CONCLUSION

RFA is less invasive, although both LLR and RFA are safe and effective. LLR provides better local control with superior recurrence-free and local-recurrence free survival. These results help optimize treatment selection based on patient-specific factors.

Oncogenic transcriptomic profile is sustained in the liver after the eradication of the hepatitis C virus

Hepatocellular carcinoma (HCC) developing after hepatitis C virus (HCV) eradication is a serious clinical concern. However, molecular basis for the hepatocarcinogenesis after sustained virologic response (SVR) remains unclear. In this study, we aimed to unveil the transcriptomic profile of post-SVR liver tissues and explore the molecules associated with post-SVR carcinogenesis. We analysed 90 RNA sequencing datasets, consisting of non-cancerous liver tissues including 20 post-SVR, 40 HCV-positive and 7 normal livers, along with Huh7 cell line specimens before and after HCV infection and eradication. Comparative analysis demonstrated that cell cycle- and mitochondrial function-associated pathways were altered only in HCV-positive non-cancerous liver tissues, whereas some cancer-related pathways were up-regulated in the non-cancerous liver tissues of both post-SVR and HCV-positive cases. The persistent up-regulation of carcinogenesis-associated gene clusters after viral clearance was reconfirmed through in vitro experiments, of which, CYR61, associated with liver fibrosis and carcinogenesis in several cancer types, was the top enriched gene and co-expressed with cell proliferation-associated gene modules. To evaluate whether this molecule could be a predictor of hepatocarcinogenesis after cure of HCV infection, we also examined 127 sera from independent HCV-positive cohorts treated with direct-acting antivirals (DAAs), including 60 post-SVR-HCC patients, and found that the elevated serum Cyr61 was significantly associated with early carcinogenesis after receiving DAA therapy. In conclusion, some oncogenic transcriptomic profiles are sustained in liver tissues after HCV eradication, which might be a molecular basis for the liver cancer development even after viral clearance. Among them, up-regulated CYR61 could be a possible biomarker for post-SVR-HCC.

DNA methyltransferase 3B plays a protective role against hepatocarcinogenesis caused by chronic inflammation via maintaining mitochondrial homeostasis

Most hepatocellular carcinomas (HCCs) develop on the basis of chronic hepatitis, but the mechanism of epigenetic regulation in inflammatory hepatocarcinogenesis has yet to be elucidated. Among de novo DNA methyltransferases (DNMTs), DNMT3B has lately been reported to act specifically on actively transcribed genes, suggesting the possibility that it plays a role in the pathogenesis of cancer. We confirmed that DNMT3B isoforms lacking its catalytic domain were highly expressed in HCCs compared with non-tumorous liver tissue. To elucidate the role of DNMT3B in hepatocarcinogenesis, we generated a genetically engineered mouse model with hepatocyte-specific Dnmt3b deletion. The liver of the Dnmt3b-deficient mice exhibited an exacerbation of thioacetamide-induced hepatitis, progression of liver fibrosis and a higher incidence of HCC compared with the liver of the control mice. Whole-genome bisulfite sequencing verified a lower CG methylation level in the Dnmt3b-deficient liver, demonstrating differentially methylated regions throughout the genome. Transcriptome analysis revealed decreased expression of genes related to oxidative phosphorylation in the Dnmt3b-deficient liver. Moreover, primary hepatocytes isolated from the Dnmt3b-deficient mice showed reduced mitochondrial respiratory capacity, leading to the enhancement of oxidative stress in the liver tissue. Our findings suggest the protective role of DNMT3B against chronic inflammation and HCC development via maintaining mitochondrial homeostasis.

Current status of treatment with immune checkpoint inhibitors for gastrointestinal, hepatobiliary, and pancreatic cancers

The development of immune checkpoint inhibitors (ICIs) targeting cytotoxic T lymphocyte antigen 4 (CTLA-4), programmed cell death protein 1 (PD-1), or programmed cell death protein ligand 1 (PD-L1) has revolutionized the treatment strategy in various types of cancers. In addition, recent studies have revealed that tumor microsatellite instability (MSI) status and tumor mutation burden (TMB) contribute significantly to the therapeutic response to anti-PD-1 monoclonal antibody (mAb), which led to an accelerated approval to pembrolizumab for the treatment of MSI-high or mismatch-repair-deficient solid tumors after conventional chemotherapies in 2017 and for the treatment of TMB-high solid tumors in 2020 by the United States Food and Drug Administration (FDA). In the field of gastrointestinal cancers, many clinical trials evaluating the safety and efficacy of various regimens such as ICI monotherapy, the combination of anti-CTLA-4 mAb and anti-PD-1/PD-L1 mAb, and combination of ICI and conventional chemotherapy or tyrosine kinase inhibitor have been reported or are in progress. This review summarizes MSI status and TMB in gastrointestinal, hepatobiliary, and pancreatic cancers, and provides the results of most relevant clinical trials evaluating ICIs. We also discuss the development of biomarkers required for improving the selection of patients with a high probability of benefiting from treatment with ICIs, and potential therapeutic strategies that could help to enhance anticancer responses of ICIs.

Hepatitis-associated Aplastic Anemia with Rapid Progression of Liver Fibrosis Due to Repeated Hepatitis

Hepatitis-associated aplastic anemia (HAAA) is a variant of acquired aplastic anemia and characterized by bone marrow failure that follows the development of acute hepatitis. We herein report a rare case of HAAA with rapid progression of liver fibrosis due to repeated hepatitis. A pathological examination of liver specimens revealed liver fibrosis progression over a short period. Immunosuppressive therapy with cyclosporine effectively cured both the pancytopenia and hepatitis. Our case suggests that the pathological examination of the liver tissue is useful for determining a treatment plan and that immunosuppressive therapy is a promising treatment for both aplastic anemia and persistent hepatitis.

Microsatellite instability and immune checkpoint inhibitors: toward precision medicine against gastrointestinal and hepatobiliary cancers

Recent innovations in the next-generation sequencing technologies have unveiled that the accumulation of genetic alterations results in the transformation of normal cells into cancer cells. Accurate and timely repair of DNA is, therefore, essential for maintaining genetic stability. Among various DNA repair pathways, the mismatch repair (MMR) pathway plays a pivotal role. MMR deficiency leads to a molecular feature of microsatellite instability (MSI) and predisposes to cancer. Recent studies revealed that MSI-high (MSI-H) or mismatch repair-deficient (dMMR) tumors, regardless of their primary site, have a promising response to immune checkpoint inhibitors (ICIs), leading to the approval of the anti-programmed cell death protein 1 monoclonal antibody pembrolizumab for the treatment of advanced or recurrent MSI-H/dMMR solid tumors that continue to progress after conventional chemotherapies. This new indication marks a paradigm shift in the therapeutic strategy of cancers; however, when considering the optimum indication for ICIs and their safe and effective usage, it is important for clinicians to understand the genetic and immunologic features of each tumor. In this review, we describe the molecular basis of the MMR pathway, diagnostics of MSI status, and the clinical importance of MSI status and the tumor mutation burden in developing therapeutic strategies against gastrointestinal and hepatobiliary malignancies.

Dose Intensity/Body Surface Area Ratio is a Novel Marker Useful for Predicting Response to Lenvatinib against Hepatocellular Carcinoma

Lenvatinib was recently approved as a novel first-line molecular targeted agent (MTA) for treating hepatocellular carcinoma (HCC). The importance of relative dose intensity (RDI) has been shown in the treatment of various types of cancers. However, RDI may not accurately reflect the treatment intensity of lenvatinib, as it is the first oral MTA where the dose is based on the patient's weight. We aimed to evaluate the utility of 2M-DBR (the delivered dose intensity/body surface area ratio at 60 days) by comparing the relationship between 2M-DBR, 2M-RDI (RDI at 60 days), and the therapeutic response. The therapeutic response to lenvatinib was evaluated in 45 patients who underwent computed tomography 8-12 weeks after treatment initiation. We also investigated the clinical factors associated with high 2M-DBR. The area under the receiver operating characteristic of 2M-DBR that predicts the response to lenvatinib was higher than that of 2M-RDI (0.8004 vs. 0.7778). Patients with high 2M-DBR achieved significantly better objective responses and disease control rates than those with low 2M-DBR (p < 0.0001 and 0.0008). Patients with high 2M-DBR experienced significantly longer progression-free survival (PFS) than those with low 2M-DBR (p = 0.0001), while there was no significant correlation between 2M-RDI levels and PFS (p = 0.2198). Patients who achieved higher levels of 2M-DBR had a significantly better modified ALBI grade (p = 0.0437), better CONUT score (p = 0.0222), and higher BTR (p = 0.0281). Multivariate analysis revealed that high 2M-DBR was the only significant factor associated with longer PFS. In conclusion, 2M-DBR could be an important factor that reflects treatment intensity and useful for predicting the response to lenvatinib against HCC, instead of 2M-RDI.