Current Trends and Characteristics of Hepatocellular Carcinoma in Patients with Autoimmune Liver Diseases

Does autoimmune disease impair the survival of hepatocellular carcinoma patients undergoing liver resection? A multi-institutional observational study

BACKGROUND

Patients with autoimmune diseases (AD) generally carry an increased risk of developing cancer. However, the effect of AD in hepatocellular carcinoma (HCC) patients receiving surgical treatment is uncertain. The present study aimed to investigate the potential influence of AD on the survival of HCC patients undergoing hepatectomies.

METHODS

Operated HCC patients were identified from the Chang Gung Research Database, and the survival outcomes of HCC patients with or without AD were analyzed ad compared. Cox regression model was performed to identify significant risk factors associated with disease recurrence and mortality.

RESULTS

From 2002 to 2018, a total of 5532 patients underwent hepatectomy for their HCC. Among them, 229 patients were identified to have AD and 5303 were not. After excluding cases who died within 30 days of surgery, the estimated median overall survival (OS) was 43.8 months in the AD (+) group and 47.4 months in the AD (-) group (P = 0.367). The median liver-specific survival and disease-free survival (DFS) were also comparable between the two groups. After Cox regression multivariate analysis, the presence of AD did not lead to a higher risk of all-cause mortality, liver-specific mortality, or disease recurrence.

CONCLUSION

Our study demonstrated that autoimmune disease does not impair the OS and DFS of HCC patients undergoing liver resections. AD itself is not a risk factor for tumor recurrence after surgery. Patients eligible for liver resections, as a result, should be considered for surgery irrespective of the presence of AD. Further studies are mandatory to validate our findings.

Management of hepatocellular carcinoma, an important cause of death in Japanese autoimmune hepatitis patients

BACKGROUND

Hepatocellular carcinoma (HCC) in autoimmune hepatitis (AIH) was considered rare but is increasing with prolonged prognosis. Its impact on the overall prognosis of AIH is unknown, and treatment has not been established.

AIM

To investigate the risk factors and prognosis of HCC in patients with AIH and identify appropriate management strategies.

METHODS

We studied patients with AIH including background liver disease, sex, age, complications, treatment, response to treatment, liver fibrosis, prognosis, and treatment.

RESULTS

In 131 patients, deaths due to liver failure were more common early after the onset of AIH; however, deaths due to HCC increased gradually. HCC was observed in 12 patients (median age, 70 years; male/female, 4/8; cirrhosis at onset, 11; median time to carcinogenesis, 7 years). Cirrhosis at diagnosis was identified as a risk factor for carcinogenesis in the multivariate analysis (odds ratio, 41.36; p < 0.0001) and cumulative cancer rates were high. Multidisciplinary therapy other than immune checkpoint inhibitors was administered as treatment for HCC. Two of the three patients who used molecular-targeted drugs discontinued the treatment because of adverse events.

CONCLUSION

HCC is an important cause of death in patients with AIH. Currently available drug therapies are limited and early detection is desirable.

TRIAL REGISTRATION

This trial was retrospectively registered in the Ethics Committee of Kagawa University School of Medicine under the identifier 2019 - 238, registered on 4 Feb 2020.

Current Perspectives on the Molecular and Clinical Relationships between Primary Biliary Cholangitis and Hepatocellular Carcinoma

Primary biliary cholangitis (PBC) is an autoimmune liver disease characterised by the immune-mediated destruction of small and medium intrahepatic bile ducts, with variable outcomes and progression. This review summarises the state of the art regarding the risk of neoplastic progression in PBC patients, with a particular focus on the molecular alterations present in PBC and in hepatocellular carcinoma (HCC), which is the most frequent liver cancer in these patients. Major risk factors are male gender, viral infections, e.g., HBV and HCV, non-response to UDCA, and high alcohol intake, as well as some metabolic-associated factors. Overall, HCC development is significantly more frequent in patients with advanced histological stages, being related to liver cirrhosis. It seems to be of fundamental importance to unravel eventual dysfunctional molecular pathways in PBC patients that may be used as biomarkers for HCC development. In the near future, this will possibly take advantage of artificial intelligence-designed algorithms.

PD-1/PD-L1 immune checkpoint therapy demonstrates favorable safety profile in patients with autoimmune and cholestatic liver disease

Introduction

Immune checkpoint inhibitors (ICI) have revolutionized the treatment of many malignancies in recent years. However, immune-related adverse events (irAE) are a frequent concern in clinical practice. The safety profile of ICI for the treatment of malignancies in patients diagnosed with autoimmune and cholestatic liver disease (AILD) remains unclear. Due to this uncertainty, these patients were excluded from ICI clinical trials and ICI are withheld from this patient group. In this retrospective multicenter study, we assessed the safety of ICI in patients with AILD.

Methods

We contacted tertiary referral hospitals for the identification of AILD patients under ICI treatment in Europe via the European Reference Network on Hepatological Diseases (ERN RARE-LIVER). Fourteen centers contributed data on AILD patients with malignancies being treated with ICI, another three centers did not treat these patients with ICI due to fear of irAEs.

Results

In this study, 22 AILD patients under ICI treatment could be identified. Among these patients, 12 had primary biliary cholangitis (PBC), five had primary sclerosing cholangitis (PSC), four had autoimmune hepatitis (AIH), and one patient had an AIH-PSC variant syndrome. Eleven patients had hepatobiliary cancers and the other 11 patients presented with non-hepatic tumors. The applied ICIs were atezolizumab (n=7), durvalumab (n=5), pembrolizumab (n=4), nivolumab (n=4), spartalizumab (n=1), and in one case combined immunotherapy with nivolumab plus ipilimumab. Among eight patients who presented with grade 1 or 2 irAEs, three demonstrated liver irAEs. Cases with grades ≥ 3 irAEs were not reported. No significant changes in liver tests were observed during the first year after the start of ICI.

Discussion

This European multicenter study demonstrates that PD-1/PD-L1 inhibitors appear to be safe in patients with AILD. Further studies on the safety of more potent dual immune checkpoint therapy are needed. We conclude that immunotherapy should not categorically be withheld from patients with AILD.

IL-17 Imbalance Promotes the Pyroptosis in Immune-Mediated Liver Injury Through STAT3-IFI16 Axis

Autoimmune hepatitis (AIH) affects all age group and occurs mainly in women. Pyroptosis is a novel programmed cell death featured with cell bursting and release of proinflammatory cytokines. A deeper understanding of AIH pathogenesis will contribute to novel therapy for AIH patients. Here, we aimed to investigate the role of IL-17 in immune-mediated liver injury. The levels of cytokines were measured by ELISA, and mRNA levels of STAT3 and IFN gamma-inducible protein 16 (IFI16) were detected by PCR. Expressions of STAT3, IFI16, gasdermin D and cleaved caspase-1 were measured by western-blotting. Immunohistochemical staining and transmission electron microscopy were applied to evaluate liver histopathological changes of the treated mice. Our results showed that the levels of IFI16 was increased in hepatocytes treated with IL-17 protein, and further elevated after STAT3-overexpressed (STAT3-OE) lentivirus treatment. The levels of IFI16 were reduced in hepatocytes treated with IL-17 neutralizing Ab (nAb), but were significantly increased after STAT3-OE treatment. Pyroptosis was observed in hepatocytes treated with IL-17 protein, and further cell damage was observed after STAT3-OE lentivirus treatment. Liver damage was alleviated in mice treated with IL-17 nAb, however sever damage was experienced after STAT3-OE lentivirus treatment. A binding interaction between IFI16 and STAT3 was detected in IL-17 treated hepatocytes. Glutathione transaminase activity was enhanced in concanavalin A-induced AIH mice compared to the control group (p<0.01). IL-17 plays an important role in activating STAT3 and up-regulating IFI16, which may promote the pyroptosis in AIH-related liver injury through STAT3-IFI16 axis.

Hepatocellular Carcinoma in Non-Fibrotic Liver: A Narrative Review

Hepatocellular carcinoma (HCC) in a non-fibrotic liver (F0) is considered to be rare, and there is a marked paucity of studies in the literature on this HCC type. A review of the literature shows some important clinical and tumor characteristics: (a) it occurs mainly in young female and elder male patients; (b) clinically, under normal hepatic function, alpha-fetoprotein level is often normal, and there are no risk factors; (c) associated with metabolic disease; (d) macroscopically, single large lesions are noted; and (e) microscopically, the lesions are well-differentiated and encapsulated. Radiological imaging results are straightforward, showing arterial hyperenhancement and later wash-out. The combined use of B-mode and contrast-enhanced (CE) ultrasound (US) is the most reliable and cost-effective diagnostic method. Few peri-and post-operative complications are noted and 5-year survival is not inferior to patients with HCC on fibrosis liver despite the lesion's large size. Most clinicians believe that HCC is unlikely to occur if patients have no symptoms and normal hepatic function. Although detailed clinical data are very limited, we expect that this review will help to improve the clinical management of HCC in non-fibrotic livers.

[Sex-specific differences in gastroenterological diseases]

Diseases of the gastrointestinal tract present with substantial sex differences that have a potential impact on patient outcome. This fact is not sufficiently addressed either in basic research or in clinical studies. For example, most animal studies utilize male animals. Despite differences in incidence, sex may affect complication rates, prognosis, or therapeutic response. The incidence of gastrointestinal cancers is frequently higher in males, but this observation cannot solely rely on a distinct risk behaviour. Here, differences in immune response and p53 signalling may be factors responsible for this finding. Nevertheless, taking sex differences into account and improving our understanding of relevant mechanisms is crucial and will most likely have a substantial impact on disease outcome. This overview aims to highlight sex differences in the context of various gastroenterological diseases, primarily to enhance awareness. Attention to sex-specific differences is essential to improve individualized treatment.

Overlap syndrome of autoimmune hepatitis and primary biliary cholangitis complicated with atypical hepatocellular carcinoma: a case report

BACKGROUND

Hepatocellular carcinoma (HCC) is a primary tumor of the liver. The majority of HCCs are associated most frequently with chronic B or C viral hepatitis, alcohol intake or aflatoxin exposure. Cirrhosis is a strong risk factor associated with HCC. The causes of liver cirrhosis are chronic viral hepatitis, alcohol intake, metabolic diseases (NAFLD), hemocromathosis, alfa 1 antitrypsisn deficiency. All aetiologic forms of cirrhosis are at risk to be complicated by HCC development, but the risk is higher for patients diagnosed with chronic viral hepatitis. Comparing to the above-mentioned causes, PBC and AIH are less associated with the risk of HCC development. A 71-year old Caucasian female previously diagnosed with overlap syndrome (AIH type 1 and PBC-ANA, SMA and AMA antibodies positive), liver cirrhosis, a nodule in the VI/VIIth hepatic segment, systemic sclerosis sine scleroderma, Hashimoto's thyroiditis, antiphospholipid syndrome, gastric antral vascular ectasia (GAVE) (with 2 previous sessions of argon plasma coagulation), cholecystectomy, arterial hypertension and nephro-angiosclerosis presented to the 2nd Department of Internal Medicine in Cluj-Napoca for a follow-up. The patient was following treatment with UDCA (Ursodeoxycholic acid), azathioprine, Plaquenil, calcium channel blockers, angiotensin-converting-enzyme inhibitor, calcium and vitamin D supplementation. The abdominal ultrasound showed a subcapsular hypoechoic nodule with a diameter of 29 mm (at the moment of the diagnosis the diameter was 9/10 mm) in the VI/VIIth hepatic segment. The contrast-enhanced ultrasound (CEUS) characterised the nodule as specific for hepatocellular carcinoma (LI-RADS 5). On MRI with gadoxetate disodium the nodule was hypovascular, non-specific, being classified as LI-RADS 3. An atypical resection of the VIIth hepatic segment was performed and the histohistological examination and imunohistochemistry (Hep Par-a positive, Glypican3 positive, CD34 positive) revealed a moderately differentiated hepatocellular carcinoma (G2), pT2 N0 M0 L0 V1 R0.

CONCLUSION

Autoimmune hepatitis, PBC and the overlap syndrome are less associated with the development of liver cirrhosis and HCC than other chronic liver diseases, especially if other risk factors are not associated. This case highlights the importance of a proper surveillance of cirrhotic patients every 6 months including abdominal ultrasound and AFP levels is crucial for an early diagnosis of a HCC.

Population-Attributable Fractions of Personal Comorbidities for Liver, Gallbladder, and Bile Duct Cancers

BACKGROUND

We aim to estimate population-attributable fractions (PAF) for 13 comorbidities potentially predisposing to hepatobiliary cancer of hepatocellular carcinoma (HCC), gallbladder cancer (GBC), cancers of the intrahepatic and extrahepatic bile ducts (ICC and ECC), and ampullary cancer.

METHODS

Patients were identified from the Swedish Inpatient Register from 1987 to 2018 and cancers from the Swedish Cancer Registry from 1997 through 2018. PAFs were calculated for each comorbidity-associated cancer using a cohort study design.

RESULTS

For male HCC, the major individual comorbidities (PAF > 10) were diabetes, alcohol-related liver disease, and hepatitis C virus infection. For female HCC, diabetes and autoimmune diseases were important contributors. For female GBC, gallstone disease was an overwhelming contributor, with a PAF of 30.57%, which was also important for men. The overall PAF for male ICC was almost two times higher than the female one. For ECC and ampullary cancer, infection of bile ducts was associated with the highest PAF.

CONCLUSIONS

The 13 comorbidities accounted for 50% or more of the potential etiological pathways of each hepatobiliary cancer except female ICC. The underlying convergent mechanism for these cancers may be chronic inflammation lasting for decades and thus offering possibilities for intervention and disease monitoring.

Primary biliary cholangitis: Epidemiology, prognosis, and treatment

Primary biliary cholangitis (PBC) is a chronic cholestatic autoimmune liver disease characterized by a destructive, small duct, and lymphocytic cholangitis, and marked by the presence of antimitochondrial antibodies. The incidence and prevalence of PBC vary widely in different regions and time periods, and although disproportionally more common among White non-Hispanic females, contemporary data show a higher prevalence in males and racial minorities than previously described. Outcomes largely depend on early recognition of the disease and prompt institution of treatment, which, in turn, are directly influenced by provider bias and socioeconomic factors. Ursodeoxycholic acid remains the initial treatment of choice for PBC, with obeticholic acid and fibrates (off-label therapy) reserved as add-on therapy for the management of inadequate responders or those with ursodeoxycholic acid intolerance. Novel and repurposed drugs are currently at different stages of clinical development not only for the treatment of PBC but also for its symptomatic management. Here, we summarize the most up-to-date data regarding the epidemiology, prognosis, and treatment of PBC, providing clinically useful information for its holistic management.

Personal comorbidities and their subsequent risks for liver, gallbladder and bile duct cancers

Many environmental risk factors for hepatobiliary cancers are known but whether they are associated with specific cancer types is unclear. We present here a novel approach of assessing standardized incidence ratios (SIRs) of previously diagnosed comorbidities for hepatocellular carcinoma (HCC), gallbladder cancer (GBC), cholangiocarcinoma (CCA) and ampullary cancer. The 13 comorbidities included alcohol and nonalcohol related liver disease, chronic obstructive pulmonary disease, gallstone disease, viral and other kinds of hepatitis, infection of bile ducts, hepatic and other autoimmune diseases, obesity and diabetes. Patients were identified from the Swedish Inpatient Register from 1987 to 2018, and their cancers were followed from 1997 onwards. SIRs for HCC were 80 to 100 in men and women diagnosed with hepatitis C virus and they were also >10 in patients diagnosed with hepatitis B virus, other kind of hepatitis, hepatic autoimmune disease and nonalcohol related liver disease. Many of these risks, as well as alcohol related liver disease, were either specific to HCC or were shared with intrahepatic CCA. For GBC, CCA and ampullary cancer infection of bile ducts was the main risk factor. Gallstone disease, nonhepatic autoimmune diseases and diabetes were associated with all hepatobiliary cancers. The limitations of the study include inability to cover some rare risk factors and limited follow-up time. Many of the considered comorbidities are characterized by chronic inflammation and/or overt immune disturbance in autoimmune diseases. The results suggest that local chronic inflammation and a related immune disturbance is the carcinogenic trigger for all these cancers.

[Treatment of Autoimmune Hepatitis]

Autoimmune hepatitis (AIH) is a chronic liver disease, characterized by elevated levels of transaminases, immunoglobulin G, and positive autoantibodies. The disease course is dynamic and presents heterogeneous disease manifestations at diagnosis. This review summarizes the issues regarding the treatment and monitoring of AIH in adult patients. Glucocorticoids and azathioprine are the first line of treatment. Alternative first-line treatments include budesonide or mycophenolate mofetil (MMF). Although no randomized controlled trials have been performed, MMF, cyclosporine, tacrolimus, 6-mercaptopurine, 6-thioguanine, allopurinol, sirolimus, everolimus, infliximab, or rituximab have been attempted in patients not responding to or intolerant to first-line treatments. Most patients require life-long special monitoring, with or without maintenance treatment.

Autoimmune diseases as comorbidities for liver, gallbladder, and biliary duct cancers in Sweden

BACKGROUND

Autoimmune diseases are associated with many cancers but there is a lack of population-based studies with different autoimmune diseases that have a long follow-up. This is also true of hepatobiliary cancers, which include hepatocellular cancer (HCC) and rarer entities of gallbladder cancer (GBC), intra- and extrahepatic cholangiocarcinoma (iCCA and eCCA), and ampullary cancer.

METHODS

Diagnostic data on 43 autoimmune diseases were collected from the Swedish Inpatient Register from 1987 to 2018, and cancer data were derived from the national cancer registry from 1997 onward. Relative risks were expressed as standardized incidence ratios (SIRs).

RESULTS

In a population of 13.6 million, 1.1 million autoimmune diseases were diagnosed and subsequent hepatobiliary cancer was diagnosed in 3191 patients (17.2% of cancers). SIRs for HCC were 2.73 (men) and 2.86 (women), 3.74/1.96 for iCCA, 2.65/1.37 for GBC, 2.38/1.64 for eCCA, and 1.80/1.85 for ampullary cancer. Significant associations between autoimmune disease and HCC were observed for 13 autoimmune diseases, with the highest risks being for autoimmune hepatitis (48.92/73.53, men/women) and primary biliary cirrhosis (38.03/54.48). GBC was increased after six autoimmune diseases, with high SIRs for ulcerative colitis (12.22/3.24) and men with Crohn disease (9.16). These autoimmune diseases were also associated with a high risk of iCCA, which had seven other associations, and eCCA, which had five other associations. Ampullary cancer occurrence was increased after four autoimmune diseases.

CONCLUSION

An autoimmune disease is a common precursor condition for hepatobiliary cancers. This calls for careful control of autoimmune disease symptoms in each patient and encouragement to practice a healthy lifestyle.

The unhealthy lifestyle in primary biliary cholangitis: An enemy to fight

BACKGROUND AND AIM

Metabolic dysfunctions, particularly hyperlipidemia, are a common finding in Primary Biliary Cholangitis (PBC). In presence of metabolic components of fatty-liver-disease (MAFLD), the liver fibrosis progression risk is higher. The aim of this study was to evaluate lifestyle of PBC patients compared to controls.

METHODS

In a prospective, multicenter study 107 PBC patients were enrolled; among these, 54 subjects were age-and sex-matched with 54 controls with a propensity-score-matching-analysis. Eating habits and physical activity were evaluated, respectively, with a food-frequency-questionnaire and with a short pre-validated-questionnaire. The adherence to Mediterranean diet was assessed with the alternate Mediterranean diet score.

RESULTS

The total fat intake was higher in controls than in PBC (p=0.004), unless above the national recommendations in both groups. Moreover, in PBC monounsaturated-fat and polyunsaturated-fatty-acid intakes and the adherence to Mediterranean diet were significantly lower than in controls (p<0.001, p=0.005 and p<0.001 respectively). Regarding physical activity, PBC subjects had a sedentary behavior as well as controls.

CONCLUSIONS

The lifestyle of both PBC and controls is at high risk of developing MAFLD. Therefore, hepatologists should regularly evaluate eating habits and physical activity in PBC patients and promote a lifestyle change to reduce liver disease progression risk.

Systemic Treatment of Advanced Unresectable Hepatocellular Carcinoma after First-Line Therapy: Expert Recommendations from Hong Kong, Singapore, and Taiwan

BACKGROUND

Asia has a high burden of hepatocellular carcinoma (HCC) due to the high rates of chronic hepatitis B infection and accounts for 70% of HCC cases globally. In the past 20 years, the systemic treatment landscape of advanced HCC has evolved substantially - from tyrosine kinase inhibitors to immune-oncology agents plus anti-vascular endothelial growth factor agents. The appropriate sequence of therapies has become critical in optimizing patient outcomes given the increase in systemic therapeutic options. This article evaluates the evidence and provides expert recommendations for the use of systemic therapies after first-line treatment in patients with advanced HCC.

SUMMARY

Based on three virtual meetings held in early 2021, a team of 17 experts comprising oncologists, a hepatologist, and a hepatobiliary surgeon from Hong Kong, Singapore, and Taiwan reviewed available data about systemic treatments for HCC after first line and formulated 28 statements. These statements aimed to provide expert guidance on selecting first and subsequent lines of therapies as well as recommending therapies in special circumstances, such as poor liver function, posttransplantation, recent gastrointestinal bleeding, or autoimmune diseases. Data supporting the statements were drawn from clinical trials and real-world studies. The 28 statements were then evaluated anonymously using a 5-point Likert scale, and 24 reached consensus, predefined as achieving 75% agreement. Statements generated covered the selection of first-line systemic therapy, considerations and goals of second-line systemic therapies, treatment selection following first-line therapy, and treatment recommendations following first-line tyrosine kinase inhibitors, immune-oncology monotherapy, or immune-oncology combination therapy. The authors also shared expert opinion on the use of second-line systemic therapy in patients with liver dysfunction, liver transplantation, and recent gastrointestinal or autoimmune disease.

KEY MESSAGES

These expert statements summarize the latest data and expert opinion on selecting systemic treatment following first-line therapy in patients with unresectable advanced or metastatic HCC.

Familiarity Breeds Strategy: In Silico Untangling of the Molecular Complexity on Course of Autoimmune Liver Disease-to-Hepatocellular Carcinoma Transition Predicts Novel Transcriptional Signatures

Autoimmune liver diseases (AILD) often lead to transformation of the liver tissues into hepatocellular carcinoma (HCC). Considering the drawbacks of surgical procedures in such cases, need of successful non-invasive therapeutic strategies and treatment modalities for AILD-associated-HCC still exists. Due to the lack of clear, sufficient knowledge about factors mediating AILD-to-HCC transition, an in silico approach was adopted to delineate the underlying molecular deterministic factors. Parallel enrichment analyses on two different public microarray datasets (GSE159676 and GSE62232) pinpointed the core transcriptional regulators as key players. Correlation between the expression kinetics of these transcriptional modules in AILD and HCC was found to be positive primarily with the advancement of hepatic fibrosis. Most of the regulatory interactions were operative during early (F0-F1) and intermediate fibrotic stages (F2-F3), while the extent of activity in the regulatory network considerably diminished at late stage of fibrosis/cirrhosis (F4). Additionally, most of the transcriptional targets with higher degrees of connectivity in the regulatory network (namely DCAF11, PKM2, DGAT2 and BCAT1) may be considered as potential candidates for biomarkers or clinical targets compared to their low-connectivity counterparts. In summary, this study uncovers new possibilities in the designing of novel prognostic and therapeutic regimen for autoimmunity-associated malignancy of liver in a disease progression-dependent fashion.

Autoimmunity as an Etiological Factor of Cancer: The Transformative Potential of Chronic Type 2 Inflammation

Recent epidemiological studies have found an alarming trend of increased cancer incidence in adults younger than 50 years of age and projected a substantial rise in cancer incidence over the next 10 years in this age group. This trend was exemplified in the incidence of non-cardia gastric cancer and its disproportionate impact on non-Hispanic white females under the age of 50. The trend is concurrent with the increasing incidence of autoimmune diseases in industrialized countries, suggesting a causal link between the two. While autoimmunity has been suspected to be a risk factor for some cancers, the exact mechanisms underlying the connection between autoimmunity and cancer remain unclear and are often controversial. The link has been attributed to several mediators such as immune suppression, infection, diet, environment, or, perhaps most plausibly, chronic inflammation because of its well-recognized role in tumorigenesis. In that regard, autoimmune conditions are common causes of chronic inflammation and may trigger repetitive cycles of antigen-specific cell damage, tissue regeneration, and wound healing. Illustrating the connection between autoimmune diseases and cancer are patients who have an increased risk of cancer development associated with genetically predisposed insufficiency of cytotoxic T lymphocyte-associated protein 4 (CTLA4), a prototypical immune checkpoint against autoimmunity and one of the main targets of cancer immune therapy. The tumorigenic process triggered by CTLA4 insufficiency has been shown in a mouse model to be dependent on the type 2 cytokines interleukin-4 (IL4) and interleukin-13 (IL13). In this type 2 inflammatory milieu, crosstalk with type 2 immune cells may initiate epigenetic reprogramming of epithelial cells, leading to a metaplastic differentiation and eventually malignant transformation even in the absence of classical oncogenic mutations. Those findings complement a large body of evidence for type 1, type 3, or other inflammatory mediators in inflammatory tumorigenesis. This review addresses the potential of autoimmunity as a causal factor for tumorigenesis, the underlying inflammatory mechanisms that may vary depending on host-environment variations, and implications to cancer prevention and immunotherapy.

Hepatocellular carcinoma in viral and autoimmune liver diseases: Role of CD4+ CD25+ Foxp3+ regulatory T cells in the immune microenvironment

More than 90% of cases of hepatocellular carcinoma (HCC) occurs in patients with cirrhosis, of which hepatitis B virus and hepatitis C virus are the leading causes, while the tumor less frequently arises in autoimmune liver diseases. Advances in understanding tumor immunity have led to a major shift in the treatment of HCC, with the emergence of immunotherapy where therapeutic agents are used to target immune cells rather than cancer cells. Regulatory T cells (Tregs) are the most abundant suppressive cells in the tumor microenvironment and their presence has been correlated with tumor progression, invasiveness, as well as metastasis. Tregs are characterized by the expression of the transcription factor Foxp3 and various mechanisms ranging from cell-to-cell contact to secretion of inhibitory molecules have been implicated in their function. Notably, Tregs amply express checkpoint molecules such as cytotoxic T lymphocyte-associated antigen 4 and programmed cell-death 1 receptor and therefore represent a direct target of immune checkpoint inhibitor (ICI) immunotherapy. Taking into consideration the critical role of Tregs in maintenance of immune homeostasis as well as avoidance of autoimmunity, it is plausible that targeting of Tregs by ICI immunotherapy results in the development of immune-related adverse events (irAEs). Since the use of ICI becomes common in oncology, with an increasing number of new ICI currently under clinical trials for cancer treatment, the occurrence of irAEs is expected to dramatically rise. Herein, we review the current literature focusing on the role of Tregs in HCC evolution taking into account their opposite etiological function in viral and autoimmune chronic liver disease, and we discuss their involvement in irAEs due to the new immunotherapies.