Search tips
Search criteria 


Logo of transbThe Royal Society PublishingPhilosophical Transactions BAboutBrowse By SubjectAlertsFree Trial
Philos Trans R Soc Lond B Biol Sci. 2017 October 19; 372(1732): 20160274.
Published online 2017 September 11. doi:  10.1098/rstb.2016.0274
PMCID: PMC5597741

Viral hepatitis and liver cancer


Hepatitis B and C viruses are a global health problem causing acute and chronic infections that can lead to liver cirrhosis and hepatocellular carcinoma (HCC). These infections are the leading cause for HCC worldwide and are associated with significant mortality, accounting for more than 1.3 million deaths per year. Owing to its high incidence and resistance to treatment, liver cancer is the second leading cause of cancer-related death worldwide, with HCC representing approximately 90% of all primary liver cancer cases. The majority of viral-associated HCC cases develop in subjects with liver cirrhosis; however, hepatitis B virus infection can promote HCC development without prior end-stage liver disease. Thus, understanding the role of hepatitis B and C viral infections in HCC development is essential for the future design of treatments and therapies for this cancer. In this review, we summarize the current knowledge on hepatitis B and C virus hepatocarcinogenesis and highlight direct and indirect risk factors.

This article is part of the themed issue ‘Human oncogenic viruses’.

Keywords: hepatitis B, hepatitis C, chronic viral hepatitis, hepatocellular carcinoma, hepatocarcinogenesis, virus-induced cancer

1. Hepatitis B virus infection

Hepatitis B virus (HBV) is one of the most common chronic infections worldwide, with an estimated 257 million chronically infected subjects, and the leading cause for hepatocellular carcinoma (HCC) worldwide [1]. Owing to the high risk of developing end-stage liver disease or HCC, chronic hepatitis B (CHB) is associated with high mortality (15–40% in 10–25 years) [2], with about 880 000 deaths per year due to complications of CHB (WHO 2017). The occurrence of symptoms in the context of acute infection is age-dependent. Most infections in children are clinically silent. In adults, up to 70% of cases show subclinical hepatitis with an increase in transaminases, and in up to 30% of cases a transient jaundice and flu-like prodromal stage [1]. Acute HBV infection can also result in fulminant hepatitis with liver failure (less than 1% of cases); however, acute symptoms are usually transient and self-limiting. The clinical course of CHB is often inapparent until late-stage liver disease is evident.

The prevalence of HBV infections varies in different geographical regions, with highest rates in sub-Saharan Africa and East Asia, where 5–10% of the adult population is chronically infected. High rates of infection are reported in the Amazon and southern parts of eastern and central Europe. In the Middle East and the Indian subcontinent, an estimated 2–5% of the population is chronically infected. Less than 1% of the Western European and North American population is chronically infected (WHO 2016). This risk of acquiring HBV infection was drastically reduced by increased hygiene standards, screening of blood products and introduction of a prophylactic vaccine [3]. Despite the availability of this vaccine for more than 40 years, the number of infections remains high, owing in part to the failure to implement vaccination programmes and also to a high number of perinatal infections in endemic areas [1,3]. To reduce perinatal infection, nucelos(t)ide analogue treatment of highly viraemic mothers may be necessary, in addition to postnatal treatment with hepatitis B immunoglobulin and HBV vaccination [4]. Despite these treatments, more than 10% of infants born to highly viraemic mothers acquire HBV infection despite active and passive vaccination [46]. Lamivudine, telbivudine and tenofovir have been shown to be safe and to reduce the risk of intrauterine and perinatal HBV transmission when given in concert with passive and active vaccination [4,6].

HBV is a partially double-stranded DNA virus that replicates via reverse transcription. In contrast with retroviruses, such as human immunodeficiency virus (HIV), integration of the viral DNA is not an essential step in the virus life cycle. HBV is characterized by its narrow host range and tissue tropism to replicate in hepatocytes. The virus persists via an episomal transcription template within the nucleus of infected hepatocytes that is defined as covalently closed circular DNA (cccDNA) [7]. The viral genome has four overlapping open reading frames encoding the structural core (HBc) and envelope proteins, the viral polymerase/reverse transcriptase and regulatory X protein (HBx), which is regarded as an oncoprotein. Three envelope proteins of different sizes (small (S), medium (M) and large (L)) are encoded by the same open reading frame with M and L carrying N-terminal extensions. Although regarded to be irrelevant for the virus life cycle, non-circularized HBV genomes have been reported to integrate into the hepatocellular genome [8].

A limited number of HBV virions (1–10) are sufficient to initiate infection, and the virus is transmitted via contact with blood or body fluids during sexual intercourse and vertically from mother to child. The latter accounts for the high number of chronic carriers because infection around birth and during early childhood results in high chronicity rates of greater than 90%. By contrast, infection of adolescents or adults largely results in acute infections with only 1–5% of subjects developing chronic infection [1]. The ‘natural’ history of chronic HBV infection is classified in specific stages that are defined by hepatic inflammatory activity and viral replication rates [9]. High viraemia is associated with the expression of pre-core antigen (HBeAg), while anti-HBe serum reactivity is observed in low-replicating infection or when viral mutants emerge. Traditionally, the HBeAg status has been used as a parameter to assess viral replicative fitness and disease prognosis [2]. However, current studies support the predictive value of HBV-DNA levels to estimate HCC risk and disease prognosis [9].

2. Hepatitis C virus infection

Worldwide, 140 million infections with hepatitis C virus (HCV) are estimated [10,11]. The lack of proof-reading capacity of the HCV-encoded polymerase along with high replication rates results in a high mutation rate and genesis of a heterogeneous but closely related quasi-species [12]. HCV is transmitted via parenteral routes, occurs in industrialized countries via intravenous drug abuse or by invasive sexual practices and is rarely transmitted from mother to child. Transmission has been limited by improving hygienic standards. In contrast with HBV, the risk of viral persistence and the development of chronic HCV infection in children are lower than those in adults. HCV has a very different prevalence depending on demographic factors: approximately 1.6% in the USA, less than 0.5% in Northern Europe and up to 3% in rural regions of Romania [11]; the most-affected regions are Central and East Asia and North Africa.

Acute HCV infection is asymptomatic in most cases, and only 15% of cases are symptomatic with symptoms such as fatigue, nausea, joint pain or signs of liver damage (jaundice and increased liver enzymes). The majority of adults develop chronic infection (55–85%), with 15–45% resolving infection within the first six months. It has been reported that 350 000–500 000 people die each year from HCV-related liver diseases such as liver cirrhosis or HCC (WHO 2016). Chronic hepatitis C (CHC) shows a variable clinical course, ranging from mild histopathological changes to highly active hepatitis and the development of liver fibrosis, cirrhosis and HCC over several decades.

CHC is a slowly progressive disease characterized by persistent hepatic inflammation resulting in liver fibrosis and liver cirrhosis. Since fibrosis progression is not linear, estimating its prognosis is difficult. Persistent hepatic inflammation leads to the development of cirrhosis in approximately 10–20% of patients over 20 years, while other studies report a 40% cirrhosis risk over 30 years [11,13]. Once high-grade fibrosis (Ishak grade 3 or 4) or cirrhosis has developed, there is a 1–5% annual risk of developing HCC. However, only a minority of HCV-infected individuals develop cancer, suggesting a complex interplay between viral gene expression and host and environmental factors to promote hepatocyte transformation and carcinogenesis. Transgenic mice engineered to express the HCV genome show an increased risk for HCC [14]; however, the lack of small animal models supporting HCV infection and associated pathologies limits our understanding of pathways underlying HCV-associated HCC.

HCV is a single-stranded, positive-sense RNA virus that encodes a single polyprotein that is post-translationally cleaved into structural (S) and non-structural (NS) proteins. Structural proteins include core protein, envelope E1 and E2 glycoproteins and p7 protein, and constitute the viral particle. Non-structural proteins (NS1, NS2, NS3, NS4A/B and NS5A/B) support viral genome replication and particle assembly. HCV replicates in the cytoplasm of hepatocytes and is unique among cancer-causing viruses in not encoding oncoproteins or integrating its genome into the host chromosomal DNA. The mechanisms underlying HCV-associated carcinogenesis are mainly indirect effects of virus de-regulating host cellular processes, including (i) increased hepatocyte proliferation and steatosis, (ii) virus-induced inflammation and oxidative stress inducing genomic mutations and genome instability, (iii) mitochondrial damage and induction of reactive oxygen species (ROS) and (iv) effects of virus-induced host immune responses.

3. Hepatitis delta virus infection

The hepatitis delta virus (HDV) is a satellite virus that depends on HBV for generation of progeny virus and propagation. The HDV genome comprises a circular single-stranded RNA of around 1700 bases. The antigenomic open reading frame encodes the only viral protein, hepatitis delta antigen (HDAg), that exists in two forms, the small- and the large-HDAg, and HDV particle assembly is dependent on the HBV envelope glycoprotein. Thus, HDV can only establish infection in the presence of HBV co-infection. HDV infects 15–20 million subjects worldwide and causes the most severe form of viral hepatitis. Several studies (reviewed in [15]) have shown that chronic HDV co-infection leads to a more pronounced inflammation and severe liver disease than HBV mono-infection. In addition, HDV accelerates the course of progression to fibrosis and cirrhosis, and increases the risk for HCC development and early decompensation of cirrhosis [16]. HDV accounts for almost half of all cases of cirrhosis and HCC in high-epidemic regions such as southeast Turkey, Italy or Mongolia. To date, no specific antiviral treatment is available for HDV.

HDV infection is not cytopathic and HDAg is not directly oncogenic, but high-level expression and nuclear translocation can activate NFκB- and STAT3-mediated inflammatory response and oxidative stress, which promote HBV oncogenesis [17]. HDV infection is characterized by a markedly increased inflammatory liver disease with necro-inflammation and increased hepatocyte turn-over compared with HBV mono-infection, rendering active hepatitis as the lead course why HDV accelerates HCC development.

4. Hepatocellular carcinoma epidemiology, risk factors and treatment options

Worldwide, liver cancer is the second leading cause of cancer-related death in men, with 745 000 deaths per year, and the sixth most common cancer, with rising incidence (approx. 800 000 new cases each year) [18]. HCC represents approximately 90% of all primary liver cancer cases, shows a clear gender disparity towards males and is a major cancer in less developed regions, with a correlation to HBV surface antigen prevalence. Chronic HBV and HCV infections represent the leading cause for HCC (60–70%), with a total incidence of 16/100 000 globally. In most of Africa and Asia, HBV is the single leading risk factor for HCC, whereas in Japan, northern Europe and the USA HCV is the major risk factor [19]. The risk of developing HCC is 10- to 25-fold higher in CHB [20] compared with non-infected controls, and up to 17-fold increased in HCV-associated liver cirrhosis [19]. While HCC in HCV infection rarely occurs without liver cirrhosis, CHB without any obvious liver inflammation per se confers a risk for HCC development. The highest risk for HCC development is associated with co-infection of HBV with HDV, HCV or HIV.

A reduction of HCC incidence in some high-risk countries can be attributed to HBV vaccination programmes and increased hygienic standards mainly because aflatoxins are known to increase HCC risk [18,21]. This is as well mirrored by HCC attributable to HBV being far less common in northwestern Europe (18%) and the USA (20% of cases) when compared with 51% in eastern/southern Europe and 65% in the Far East and China [21,22]. Nevertheless, liver cancer incidence steadily increased in areas with historically low rates, including parts of Oceania, Western Europe and North America. For example, a rise from 2.6 to 8.6 per 100 000 was observed in the USA between 1975 and 2011, which was partially attributable to the increase in HCV-associated liver cirrhosis 20–40 years after infection and high prevalence of metabolic syndrome as an independent risk and cofactor [21].

HCC high mortality is most likely due to the resistance of this tumour to chemotherapy along with concomitant complications of end-stage liver disease and frequent diagnosis at late stages when limited treatment options are available. Thus, in contrast with other cancer types, HCC classification is not based on the ‘classical’ TNM tumour-staging/grading but on a clinical score based on the number of HCC nodules, size, vascular invasion, stage of cirrhosis and the Eastern Cooperative Oncology Group Performance Status: the Barcelona Clinic Liver Cancer (BCLC) staging classification [2325]. While in the early stages (BCLC 0/A) patients are eligible for potentially curative therapies (i.e. surgical resection and liver transplantation (within MILAN criteria [26]) and radiofrequency ablation and median survival rates of 60 months and beyond can be reached. However, fewer than 40% of patients are diagnosed at early stages, and in advanced HCC only palliative treatment options are available, with poor overall survival [2325].

Thus, there is an urgent need for effective and tolerable treatments for HCC. However, besides the multikinase inhibitors sorafenib and regarofenib, which improve median overall survival by only approximately three months [27], more than 100 trials evaluating chemotherapy or targeted therapies in HCC failed to show survival advantages [28,29]. New promising approaches include immune checkpoint inhibitors [30] and adoptive T-cell transfer approaches [31]. The poor outcome of targeted therapies in late-stage HCC is a result of a diverse spectrum of HCC subtypes, without common growth addiction loops. Thus, it is of the utmost importance to understand the causes of HCC development and to find novel approaches.

Substantial progress has been made in understanding the molecular mechanisms of hepatocarcinogenesis. In chronic viral hepatitis as well as in other aetiologies of HCC (i.e. alcoholic liver disease, non-alcoholic fatty liver disease and certain rare metabolic, autoimmune or hereditary liver diseases) chronic inflammation, cell death and compensatory hepatocyte proliferation referred to as necro-inflammation is an important driver of liver fibrosis. The single most evident risk factor for HCC is liver cirrhosis. Well-known cofactors for HCC development are increasing age (greater than 40 years), duration of infection, male gender, alcohol consumption, cigarette smoking, co-infection with HBV/HCV, HDV or HIV and exposure to aflatoxin B1 [32].

The risk for HCC in CHB and CHC is closely linked to liver inflammation during chronic infection. Both viral infections are non-cytopathic and liver damage is thought to be induced by viral-specific CD8+ T- and natural killer (NK) cells rather than by the viruses themselves [33,34]. Events driving hepatocyte transformation include DNA damage, epigenetic modifications, mitochondrial alteration, senescence and chromosomal aberrations [35]. ROS or nitrogen compounds are produced by macrophages and neutrophils in inflammation, which can attack DNA, leading to adducts that impair base-pairing and/or block DNA replication and transcription, and to base loss or DNA-strand breaks [36].

5. Clinical features of hepatitis B virus-associated hepatocellular carcinoma

While in CHC HCC almost exclusively develops in liver cirrhosis, up to 20% of HBV-driven HCC cases occur in the absence of cirrhosis [27,37]. The levels of HBV replication reflected by HBV-DNA serum titres, concomitant liver inflammation and necroinflammatory tissue damage have been confirmed as the most important predictors of disease progression and HCC development. The risk for HCC correlates with HBV viraemia [38]. This was first described in the REVEAL-HBV study, where mortality increased with baseline HBV-DNA levels from 9 (fewer than 300 copies ml−1) to 267 (more than 106 copies ml−1) deaths due to chronic liver disease and cirrhosis, and 73–816 deaths per 100 000 person-years due to HCC, respectively [38]. Multivariate Cox regression analyses of risk factors predicting progression to mortality identified increasing HBV-DNA levels as the strongest independent predictor of death from chronic liver disease and cirrhosis, and this was second to cirrhosis in predicting death from HCC [39]. This effect was specific because there was no association between serum HBV-DNA levels and non-liver-related mortality.

A study with 2946 HBsAg seropositive individuals during the natural course of disease showed a reduced risk of developing HCC after seroclearance of HBeAg and in particular after resolving HBV-DNA and HBsAg expression during follow-up [40]. Among HBeAg seronegative participants with detectable serum HBV-DNA at study entry, the lifetime cumulative incidence of HCC was 14.2% if patients remained HBV-DNA and HBsAg positive, 6.6% after clearance of HBV-DNA without loss of HBsAg and 4.0% even after seroconversion to anti-HBs [40]. Importantly, patients cured of CHB remain at risk of developing HCC.

6. The role of hepatitis B virus in promoting hepatocarcinogenesis

CHB-associated inflammation and liver damage foster the accumulation of genetic and epigenetic defects that lead to the onset of HCC. However, a direct and specific contribution of the virus is supported by clinical observations and experimental data. Thus, HCC develops in 10–20% of HBV-infected individuals who lack any sign of cirrhosis. HCC can even develop in the absence of inflammation, which is in stark contrast with most other aetiologies associated with HCC [20]. HBV has a number of features that are known to contribute to HCC development independently of inflammation [11,41,42]. HBV genomes can integrate into the host genome and induce chromosomal alterations and insertional mutagenesis of cancer genes [41]. High-throughput next-generation sequencing approaches identified some recurrent sites for integration in biopsies taken from HCC but at low incidence (i.e. telomerase reverse transcriptase (TERT), myeloid/lymphoid or mixed-lineage leukemia 4 (MLL4), cyclin E1 (CCNE1), neurotrophic tyrosine kinase receptor type 2 (NTRK2), interleukin-1 receptor-associated kinase-like 2 (IRAK2), mitogen-activated protein kinase 1 (MAPK1)) [43,44]. In addition, viral promoter-driven human transcripts have been reported within or close to repetitive, non-coding sequences, such as LINEs (long interspersed nuclear elements) or SINEs (short interspersed nuclear elements) [45]. Although, taken together, HBV integration is random and rarely leads to direct oncogene activation or inactivation of a common tumour suppressor [46], it is widely accepted that integration contributes to the genetic instability of the hepatocyte and marks clonally growing hepatocytes.

Hepatocytes are self-renewing cells [47] that can proliferate to maintain liver mass during injury [48]. Necroinflammatory viral hepatitis is associated with increased hepatocyte proliferation that can maintain integrated HBV-DNA, and consequently, epigenetic and genetic dysregulation, including damage via HBV-DNA integration, will increase over time. Mason et al. [49] reported that random HBV integration events increased hepatocyte turn-over and that clonal expansion of hepatocytes occurs in HBV-infected individuals before liver damage is clinically apparent. Since integration of HBV-DNA is a risk factor for HCC development, this study proposes a model where HBV-associated hepatocarcinogenesis occurs prior to the onset of liver fibrosis or cirrhosis and provides an explanation for the limited efficacy of antiviral therapies to limit HCC progression when initiated late in the course of disease.

HBV particles package an incomplete partially double-stranded circular DNA that is imported into the nucleus where it is ‘repaired’ by cellular enzymes to cccDNA. The incomplete DNA is recognized in the nucleus as damaged and induces a DNA damage response [7,50]. While the DNA damage response can activate cell cycle checkpoints and DNA repair pathways that counteract genomic mutations in cancer, it can also lead to histone degradation, which enhances chromatin dynamics and recombination rates [51] and may promote genomic instability in HBV-associated HCC.

The HBV-encoded envelope and HBx proteins are reported to directly contribute to hepatocyte transformation via distinct and non-overlapping pathways. The envelope proteins can induce endoplasmic reticulum stress via an unfolded protein response, and transgenic mice engineered to express the envelope proteins develop liver cancer [42]. HBV-DNA sequences coding for a C-terminally truncated envelope protein are frequently found integrated in HCC. This truncated M protein may increase hepatocyte proliferation, trigger activation of c-Raf-1/Erk2, Ap-1 and NF-κB pathways and show trans-activation potential [52].

HBx plays a role in hepatocyte transformation and is a driver of HCC progression. HBx is usually expressed at low levels during infection. With increasing integration frequency of HBV-DNA during infection and associated increase in hepatocyte proliferation, relative HBx expression levels can increase and transcripts are frequently detected at high levels in HBV-related HCC [53]. HBx regulates expression of a plethora of genes involved in signal transduction pathways, cell cycle control, metastasis, transcriptional regulation, immune response and metabolism, and has been implicated as having a direct oncogenic function (summarized in [46]). Changes in signalling cascades and cellular integrity may occur from increased cytosolic calcium levels through HBx interference which stimulates HBV replication, but may have oncogenic potential by activating Src- and Ras-signalling [54]. However, the physiological relevance of these findings is difficult to prove where low-level expression of viral proteins, including HBx in the infected liver, precludes confirmation of in vitro and in vivo mouse studies which frequently overexpress HBx.

HBx is essential for HBV transcription from cccDNA and for initiating and maintaining virus replication [55]. HBx activation of HBV transcription has been proposed to be linked to chromatin modulation because HBx association with cccDNA correlates with the recruitment of acetyltransferases CBP/P300 or PCAF and acetylation of histone H3 [56]. HBx has also been reported to inhibit the methylation of histone H3 via association with histone methyltransferase ‘SETDB1’ [57]. In addition, HBx binds the DNA damage-binding protein 1 (DDB1), which in concert with cullin 4 (Cul4) is part of the E3 ubiquitinase complex [58]. Hereby, it can influence the stability of proteins such as the Smc5/6 (structural maintenance of chromosome proteins 5 and 6) complex, which binds double-stranded DNA and limits HBV transcription [59]. This might constitute an additional direct oncogenic mechanism of HBx because the Smc5/6 complex has been reported to play a role in DNA replication through natural pausing sites and in endogenous DNA damage tolerance [60].

7. Genetic risk factors in hepatocellular carcinoma development

Besides the well-known patient-specific risk factors for HCC development in CHB described above, evidence exists for a genetic predisposition due to single-nucleotide polymorphisms (SNPs) [61]. Several SNPs associated with HCC have been reported and expression profiles generated [62,63]. These polymorphisms alter biological pathways, including inflammation, oxidative stress, DNA repair, cell cycle and growth factors [64,65]. The association between aflatoxin B1 and CHB is well established, and a concomitant SNP of GTSM1 (glutathione-S-transferase mu1) and GSTT1 (glutathione-S-transferase theta1) is associated with a dramatic increase in HCC risk [66]. This indicates that the HCC risk attributable to specific polymorphisms depends on underlying risk factors and specific SNPs are associated with increased HCC risk in CHB. Such polymorphisms include SNPs of MDM2 (mouse double minute 2 homologue) and p53 [67]; XRCC3 (X-ray repair complementing defective repair in Chinese hamster cells 3) [68]; HLA (human leucocyte antigen)-DQ [64]; CTL-4 (cytotoxic T-lymphocyte antigen 4) [69]; GLB1 (galactosidase beta 1) [70] and TGF-β1 (transforming growth factor beta 1) but no other proinflammatory cytokines or interleukin-10 [71]. Nonetheless, these SNPs were mostly detected in collectives of CHB patients from the Far East or Asia and confirmatory studies in other patient populations are required.

In genome-wide association studies of HCV-related HCC, the 5′-flanking region of MICA (MHC class I polypeptide-related sequence A gene) was identified as a susceptibility locus for HCC development, consistent with reduced levels of soluble MICA protein in subjects with the risk allele, supporting an anti-tumour role for this protein [72]. Two further studies identified an SNP in a different gene, DEPDC5 (DEP domain containing 5), associated with HCC risk in Japanese [73] and progression of fibrosis in Europeans [74], although not all studies could confirm this correlation. Thus, additional studies on other populations with stratification of infecting HCV genotype and degree of cirrhosis would provide comprehensive information on the genetic aetiology and heterogeneity of HCV-related HCC. Whole exome sequencing of HCCs of diverse aetiologies has identified driver genes [63,75]; however, no specific virus-induced mutations have been identified to date. Mutations in the telomerase reverse transcriptase promoter are frequently observed in 61% of cirrhotic liver tissue samples, including HCV and HBV infection [76]. Increased TERT activity was observed in HCV core-transfected primary human hepatocytes that show an immortalized phenotype [77]. In line with this observation, somatic mutations in the TERT promoter that enhance TERT expression were shown to be among the earliest and most prevalent neoplastic events in HCC associated with all major aetiologies including HCV [78]. However, further studies are required to validate these observations in different ethnic backgrounds before these host genetic polymorphisms can be used to stratify patients for personalized surveillance or specific targeted therapies. An increased understanding of the genetic and epigenetic changes that drive HCC progression may allow improved therapies in the future; however, the underlying tumour heterogeneity makes such studies challenging.

8. A role of hepatitis C virus in promoting a pro-oncogenic microenvironment

HCV is classified into seven genotypes and epidemiological studies show that infection with genotypes 1b and 3 is associated with an increased risk of developing HCC [79,80]. Reports that HCV core gene variants are associated with HCC in patients who have resolved infection [81,82] suggest that viral factors influence progressive liver disease. CHC is often associated with insulin-resistance [83], and the core protein has been shown to dysregulate glucose homeostasis, leading to intrahepatic lipid accumulation and steatosis [84,85]. A recent study highlighted a new role for core to induce mitochondrial damage by impairing mitophagy [86]; the resulting oxidative stress is regarded as a key trigger of HCC initiation and development. In vivo studies with HCV core transgenic mice confirmed an imbalance of oxidant/antioxidant state in the liver-induced HCC [87].

HCC exhibits a high degree of genetic heterogeneity indicative of reduced genomic stability [88], and HCV induction of ROS is likely to prime DNA damage. Several studies report that HCV core or NS5A proteins increase ROS and promote oxidative stress in both mouse models and in vitro culture systems [8991]. Further studies report that HCV infection reduces host cells' ability to detect and repair damaged DNA via perturbation of ATM kinase [9294]. The physiological relevance of these studies is difficult to prove where low-level expression of viral proteins in the infected liver precludes confirmatory studies.

HCC is associated with the development of multifocal, genetically distinct tumours that are suggestive of a field defect affecting the entire liver; however, the nature of the founder cell is poorly understood. An interesting question is whether HCV can replicate in abnormal hepatocytes and act cooperatively with mutations that arise early in the progression to cancer. Harouaka et al. [95] reported reduced levels of HCV RNA in HCC compared with adjacent non-tumour tissue and observed increased viral genetic diversity in livers with HCC, supporting a model where HCV replication in the tumour is restricted and compartmentalized. By contrast, Hedegaard et al. [12] reported limited evidence of HCV intrahepatic compartmentalization in end-stage liver disease using ultra-deep sequencing technology. These studies highlight the need for further investigation into the relationship between viral diversity, host immune response and ‘phylogeography’ of the liver.

A common feature of oncogenic viruses is their ability to increase cell proliferation via inactivation of host tumour suppressors such as the retinoblastoma (Rb) protein, which represses E2F transcription factors necessary for S-phase entry into cell cycle. HCV-encoded polymerase NS5B has been reported to bind Rb, induces its degradation via host ubiquitin ligase E6AP [96,97] and promotes host cellular proliferation. A recent study showed that NS5B promotes the degradation of NORE1A tumour suppressor [98], an essential factor in HCV replication, highlighting the complexity of viral–host cell interactions. The p53 protein is a critical tumour suppressor which coordinates cell cycle arrest and apoptotic response to DNA damage and other stresses, and p53 mutations are frequently observed in HCC [99]. A number of reports show that HCV proteins core, NS3 and NS5A can associate with p53 [100]; however, the functional consequences of these interactions for p53 activity are complicated by the observation that the most permissive target cell for HCV replication used in these studies expresses a mutated inactive p53 [101]. A recent study reported that HCV induced caspase-3-mediated apoptosis via activation of NLRP3 inflammasome in infected cells and pyroptosis in both infected and non-infected cells, providing a new pathway for HCV to induce hepatocellular damage in both infected and uninfected bystander cells [102]. Despite the many potentially oncogenic features of HCV infection discussed, it is important to note that in the absence of cirrhosis, HCC rarely occurs in CHC. In advanced fibrosis or cirrhosis, HCV genotype 3 infection and insulin-resistance remain important determinants to increase HCC risk even after elimination of virus by antiviral treatment (see below).

9. Indirect effects of hepatitis C virus-induced inflammation

HCV infection is sensed by host pathogen-associated molecular pattern receptors that induce interferons (IFNs) and local inflammatory responses. HCV has evolved diverse mechanisms to antagonize these early host immune responses [103]. The majority of infected individuals develop chronic immune-mediated inflammation, accompanied by repeated cycles of hepatocyte destruction and regeneration that are considered to be key drivers in liver cancer. Activated inflammatory cells release ROS and induce lipid peroxidation, which promotes a pro-carcinogeneic environment [104]. Indeed, the observation that most HCV-associated HCC develops in a background of advanced fibrosis and cirrhosis supports a role for host inflammatory responses in this cancer.

Discovering algorithms to identify patients who will develop HCC will increase our understanding to treat and prevent HCC progression. A recent transcriptome meta-analysis including more than 500 cirrhotic human livers demonstrated global regulatory gene modules driving HCC risk and identified the lysophosphatidic acid (LPA) pathway as a central chemoprevention target [105]. LPA is a pleiotropic lipid molecule with potent effects on cell growth and motility, and emerging data highlight an important role in lymphocyte homing and inflammation [106]. Pharmacological inhibition of LPA signalling reduced tumour growth. An independent study confirmed that HCV infection increased autotaxin and associated LPA expression and reported a role for LPA to promote HCV replication [107], providing a pathway for HCV to induce proinflammatory signals that may be pro-oncogenic.

One potential mediator of cellular reprogramming is heritable (epigenetic) regulation of transcription, exemplified by DNA methylation. Tumours associated with chronic inflammation frequently show altered patterns of DNA methylation, including HCC [108]. A recent study showed increased DNA methylation of multiple genes in HCV-infected chimeric mice with humanized livers that were dependent on NK cell activity, demonstrating a role for viral-induced immune responses in regulating hepatocellular methylation status [109]. Wijetunga et al. [110] reported DNA methylation of enhancers proximal to genes implicated in liver cancer and stem cell development in HCV-associated HCC, highlighting a role for HCV to influence transcription factor binding to cognate sites in the genome. Reports showing that HCV can stabilize hypoxia-inducible factor-1α [111,112], a transcription factor that regulates vascular endothelial growth factor, provides an additional pathway for HCV to dysregulate the hepatocellular transcriptome and induce de-differentiation via regulating the epithelial-to-mesenchymal transition.

10. Effects of hepatitis B virus and hepatitis C virus on hepatocellular microRNAs

MicroRNAs (miRs) are small non-coding RNAs that regulate diverse cell functions including cell proliferation, differentiation and apoptosis. Recent reports highlight aberrant expression of miRs in hepatic tissue from subjects with liver disease and HCC [113], and provide exciting possibilities for the discovery of bio-markers for early diagnosis of viral-associated HCC [114,115].

For CHB, aberrant expression of multiple miRs has been reported to be associated with HCC development. MIR196A2 polymorphism was associated with susceptibility to HBV-related HCC in a male Chinese population [116]. HBx expression may negatively interfere with DNA repair and tumour suppressors by altering expression of multiple miRs through upregulation of HBxAg-upregulated gene 11 (URG11). HBx- and URG11-induced upregulation of miR-148a has been shown to drive cell cycle progression and cell migration by suppressing phosphatase and tensin homologue, thus increasing AKT (also known as protein kinase B)–mTOR (mammalian target of rapamycin) signalling [117]. Altered miR-122a expression inhibits HBV replication, changes the cell cycle by affecting cyclin G1 expression and inhibits expression of p27 [118].

HCV infection regulates expression of several miRs, including miR-146a-5p [119], miR-196a [120] and miR-135a-5p [27], that regulate metabolic pathways and hepatocarcinogenesis. Expression levels of the liver-specific miR-122 are inversely associated with HCC of non-viral origin and yet are conserved in HCV–HCC [121]. Since miR-122 is a critical host factor required for HCV replication, this supports a model where HCV infection of founder cells may play an important role in the carcinogenesis process.

11. Antiviral treatment and risk of hepatocellular carcinoma development

At the present time, there are no therapies to eliminate HBV infection. IFNα can cure CHB in 3–15% of patients, but has severe side effects and is rarely used. Nucleos(t)ide analogues (NAs) inhibit reverse transcription and limit HBV replication in more than 95% of treated patients and reduce liver inflammation, disease progression and HCC risk. However, these drugs have no effect on viral cccDNA or integrated copy numbers [122] and require long-term administration. Current guidelines recommend antiviral treatment only when serum HBV-DNA levels are greater than 103 copies ml−1 (i.e. greater than 2000 IU ml−1) and significant inflammatory activity indicated by increased aminotransferase activity in blood or advanced fibrosis has been diagnosed.

A systematic review showed that patients with CHB receiving NA therapy had a greater than 50% lower incidence of HCC (2.8% versus 6.4% of treated and untreated patients, respectively) during a 46 (32–108) month period (p = 0.003) [123]. The authors concluded that treatment does not eliminate the risk of HCC. In particular, liver cirrhosis, HBeAg negativity at baseline and failure to remain in virological remission were associated with an increased risk of HCC among treated patients [123]. Additional studies confirmed that patients with CHB remain at risk for HCC development [42,124] despite antiviral treatment. HBV integration and clonal hepatocyte proliferation are already observed early during the course of infection [49] and may be a cause of some of the persistent HCC risk following treatment initiation. This can be taken as an argument for earlier treatment than recommended by the current guidelines. To avoid side effects, reduce costs and minimize the risk of selecting resistant viral variants for long-term NA treatment, this would, however, require a curative treatment approach.

Several studies using IFN-based therapies reported that a sustained virological response (SVR), i.e. successful antiviral therapy that eradicates HCV, reduced the risk of HCC independently of fibrosis stage [125,126]. During an average 10-year follow-up, patients with SVR after antiviral treatment developed HCC in 2.5%, and after spontaneous HCV clearance in 1.6%, of cases, which was dependent on fibrosis stage [27]. A recent multicentre study reported the risk of HCC development in patients with liver cirrhosis to be 1% annually after SVR [127]. In a prospective study of HCV-infected patients with cirrhosis in France for an average of 51 months, a non-SVR was a major determinant of HCC occurrence after the age of 50, with a contribution of past alcohol intake, low platelet count and increased γ-glutamyl transpeptidase [128].

Treatment options for HCV have changed dramatically over the past 5 years with the approval of nucleotide NS5B polymerase inhibitor sofosbuvir in 2013, which showed SVR rates greater than 95% in combination with IFN. Since then, new direct-acting antiviral (DAA) therapies have become available with markedly fewer side effects [74], showing outstanding SVR rates of greater than 90% after eight to 12 weeks of treatment for almost all HCV genotypes. Recent studies have data steered a discussion about a potentially higher recurrence of prior, but successfully treated HCC after DAA therapy and SVR compared with historical IFN-treatment controls [129]. Data on HCC risk after DAA-based SVR only exist as a retrospective or observational study with 1-year follow-up. These studies report an annual HCC incidence rate of 3–5% following successful DAA therapy [74,130], which is higher than previous reports for patients on IFN therapy-based SVR [131]. However, these studies lack control groups, which makes the recent reports on DAA-based SVR and HCC risk hard to interpret. A French prospective cohort study showed lack of evidence of an effect of DAAs on the recurrence of HCC (80% cirrhosis, 189 patients achieving DAA-based SVR, approximately 12% HCC recurrence rate after 20 month follow-up) [132]. Randomized controlled trials will be needed to shed light on the current ongoing debate and may answer the potential role of the drop of HCV-specific immune response after DAA-induced SVR in regard to potentially increased risk of outgrowth of transformed cells and HCC reoccurrence/development.

It has, however, become clear that even the successful DAA therapies for CHC will not be able to eliminate the risk of HCC once high-grade fibrosis or cirrhosis has developed. DAA- and IFN-based regimens showed a considerably reduced, but still remaining risk (0.33%/year) for HCC after HCV cure and highlight the importance of surveillance once liver cirrhosis has developed irrespective of therapy responses [133]. Nevertheless, in countries in which the new DAA therapies are accessible, high rates of SVR and eradication of HCV will have a huge impact on cirrhosis and also HCC incidence in the coming decade.

12. Importance of surveillance

The poor prognostic outcome following late diagnosis of HCC, limited curative treatments and prolonged subclinical period of HCC highlight the urgent need for early diagnosis. At the present time, only 30–40% of patients are being diagnosed at early stages (BCLC 0/A). Stratification of patients at-risk and early diagnosis of HCC should be a main objective for forthcoming research. Cofactors such as age greater than 40 years, male gender, duration of infection, alcohol consumption, cigarette smoking, co-infection with both HBV and HCV, HDV or HIV, exposure to aflatoxin B1 and in particular the metabolic syndrome as an emerging cofactor should be taken into account for stratifying patients who need close monitoring because they are at high risk of developing HCC [11,27,35]. Surveillance can reduce mortality by up to 37% using ultrasonography and α-fetoprotein serum levels [134] and application of risk scores for stratifying patient cohorts [135].

HCC can be diagnosed by magnetic resonance imaging, computed tomography and ultrasonography. If there is not typical appearance, biopsy might be required for diagnosis. However, early HCCs are difficult to distinguish from dysplastic nodules [136]. Guidelines recommend surveillance every six months for at-risk populations [24,25], which accommodates the median tumour doubling time [137]. However, there is controversy over the use of serum markers such as α-fetoprotein as surveillance tools for early detection of HCC [27].

Stratification of patients at high risk and implementation of surveillance programmes is needed to detect HCC early. Patients with high-grade fibrosis or cirrhosis, despite successful DAA therapy and HCV cure, require surveillance, given the substantial remaining risk, with old age, diabetes and genotype 3 being independent risk factors [133]. As CHB can lead to HCC development in the absence of cirrhosis in 0.1% per year, surveillance is mandatory. Guidelines may need to be revised because family history of HCC and metabolic syndrome are risk factors for HCC development in the absence of cirrhosis [37].

13. Conclusion

Since 2000, the death toll from viral hepatitis has been constantly increasing now exceeding that of HIV infection and malaria. This rise is mainly due to HCC developing on the basis of chronic infection. HBV infection is the major single cause of HCC despite the availability of a vaccine. Therefore, WHO has called for greater efforts to increase global hepatitis B vaccination. Although global vaccination is essential, its impact is limited because the majority of CHB results from mother-to-child transmission hard to prevent. Although the risk of HCC development can be reduced by available antiviral therapy for HBV, it remains significant because the virus has particular features driving hepatocarcinogenesis. This calls for a curative treatment to complement vaccination efforts.

The currently available, highly efficient therapeutic combinations for all HCV genotypes are able to cure CHC and reduce the risk of HCC development, because HCV-associated HCC mainly occurs once liver cirrhosis has developed. These therapies need to become affordable and accessible for the majority of infected individuals. Patients who have progressed to liver cirrhosis remain at risk of developing HCC despite successful antiviral treatment. Thus, broad access to therapeutic intervention before late-stage liver disease has developed as well as surveillance even after successful therapy is required to reduce the death toll from HCC. In addition, a prophylactic vaccine is urgently needed to reduce new infections and to prevent reinfection after antiviral therapy.

Data accessibility

This article has no additional data.

Authors' contributions

M.R., J.A.M. and U.P. contributed to conception of the article, drafted the article, revised it critically for important intellectual content and approved the final version.

Competing interests

We have no competing interests.


M.R. received funding from DZIF for a clinical leave stipend and from the Else-Kröner-Stiftung as a member of the Else-Kröner-Forschungskolleg München ‘Microbial triggers in disease development’. U.P. and J.A.M. receive funding by the Institute for Advanced Study with the support of the Technical University of Munich via the German Excellence Initiative and EU 7th Framework Programme under grant agreement number 291763. Research in the McKeating laboratory is funded by the MRC, EU FP7 PathCO and H2020 grant Hep-CAR. Research in the Protzer laboratory is funded by the German Research Foundation (DFG) through the collaborative research centres TRR36 and TRR179 and by individual grant PR 618/7, by EU H2020 grant Hep-CAR, by the German Center for Infection Research (DZIF) and by the Helmholtz Validation Fund.


1. Trepo C, Chan HL, Lok A 2014. Hepatitis B virus infection. Lancet 384, 2053–2063. (doi:10.1016/S0140-6736(14)60220-8) [PubMed]
2. Fattovich G, Bortolotti F, Donato F 2008. Natural history of chronic hepatitis B: special emphasis on disease progression and prognostic factors. J. Hepatol. 48, 335–352. (doi:10.1016/j.jhep.2007.11.011) [PubMed]
3. Guidotti LG, et al. 2015. Immunosurveillance of the liver by intravascular effector CD8+ T cells. Cell 161, 486–500. (doi:10.1016/j.cell.2015.03.005) [PubMed]
4. Pan CQ, et al. 2016. Tenofovir to prevent hepatitis B transmission in mothers with high viral load. N. Engl. J. Med. 374, 2324–2334. (doi:10.1056/NEJMoa1508660) [PubMed]
5. del Canho R, et al. 1997. Ten-year neonatal hepatitis B vaccination program, The Netherlands, 1982–1992: protective efficacy and long-term immunogenicity. Vaccine 15, 1624–1630. (doi:10.1016/S0264-410X(97)00080-7) [PubMed]
6. Zhang H, Pan CQ, Pang Q, Tian R, Yan M, Liu X 2014. Telbivudine or lamivudine use in late pregnancy safely reduces perinatal transmission of hepatitis B virus in real-life practice. Hepatology 60, 448–451. (doi:10.1002/hep.27145) [PMC free article] [PubMed]
7. Lucifora J, Protzer U 2016. Attacking hepatitis B virus cccDNA—the holy grail to hepatitis B cure. J. Hepatol. 64(Suppl. 1), S41–S48. (doi:10.1016/j.jhep.2016.02.009) [PubMed]
8. Seeger C, Mason WS 2015. Molecular biology of hepatitis B virus infection. Virology 479–480C, 672–686. (doi:10.1016/j.virol.2015.02.031) [PMC free article] [PubMed]
9. Chen CJ, Yang HI 2011. Natural history of chronic hepatitis B REVEALed. J. Gastroenterol. Hepatol. 26, 628–638. (doi:10.1111/j.1440-1746.2011.06695.x) [PubMed]
10. Ferri C, et al. 2016. International diagnostic guidelines for patients with HCV-related extrahepatic manifestations. A multidisciplinary expert statement. Autoimmun. Rev. 15, 1145–1160. (doi:10.1016/j.autrev.2016.09.006) [PubMed]
11. Westbrook RH, Dusheiko G 2014. Natural history of hepatitis C. J. Hepatol. 61(Suppl. 1), S58–S68. (doi:10.1016/j.jhep.2014.07.012) [PubMed]
12. Hedegaard DL, et al. 2017. High resolution sequencing of hepatitis C virus reveals limited intra-hepatic compartmentalization in end-stage liver disease. J. Hepatol. 66, 28–38. (doi:10.1016/j.jhep.2016.07.048) [PubMed]
13. Thein HH, Yi Q, Dore GJ, Krahn MD 2008. Estimation of stage-specific fibrosis progression rates in chronic hepatitis C virus infection: a meta-analysis and meta-regression. Hepatology 48, 418–431. (doi:10.1002/hep.22375) [PubMed]
14. Rusyn I, Lemon SM 2014. Mechanisms of HCV-induced liver cancer: what did we learn from in vitro and animal studies? Cancer Lett. 345, 210–215. (doi:10.1016/j.canlet.2013.06.028) [PMC free article] [PubMed]
15. Wedemeyer H. 2011. Hepatitis D revival. Liver Int. 31(Suppl. 1), 140–144. (doi:10.1111/j.1478-3231.2010.02408.x) [PubMed]
16. Fattovich G, Giustina G, Christensen E, Pantalena M, Zagni I, Realdi G, Schalm SW, European Concerted Action on Viral Hepatitis (Eurohep) 2000. Influence of hepatitis delta virus infection on morbidity and mortality in compensated cirrhosis type B. Gut 46, 420–426. (doi:10.1136/gut.46.3.420) [PMC free article] [PubMed]
17. Abbas Z, Abbas M, Abbas S, Shazi L 2015. Hepatitis D and hepatocellular carcinoma. World J. Hepatol. 7, 777–786. (doi:10.4254/wjh.v7.i5.777) [PMC free article] [PubMed]
18. Ferlay J, Soerjomataram I, Dikshit R, Eser S, Mathers C, Rebelo M, Parkin DM, Forman D, Bray F 2015. Cancer incidence and mortality worldwide: sources, methods and major patterns in GLOBOCAN 2012. Int. J. Cancer 136, E359–E386. (doi:10.1002/ijc.29210) [PubMed]
19. El-Serag HB. 2012. Epidemiology of viral hepatitis and hepatocellular carcinoma. Gastroenterology 142, 1264 (doi:10.1053/j.gastro.2011.12.061) [PMC free article] [PubMed]
20. Fattovich G, Stroffolini T, Zagni I, Donato F 2004. Hepatocellular carcinoma in cirrhosis: incidence and risk factors. Gastroenterology 127(Suppl. 1), S35–S50. (doi:10.1053/j.gastro.2004.09.014) [PubMed]
21. Torre LA, Bray F, Siegel RL, Ferlay J, Lortet-Tieulent J, Jemal A 2015. Global cancer statistics, 2012. CA Cancer J. Clin. 65, 87–108. (doi:10.3322/caac.21262) [PubMed]
22. Levrero M, Zucman-Rossi J 2016. Mechanisms of HBV-induced hepatocellular carcinoma. J. Hepatol. 64(Suppl. 1), S84–S101. (doi:10.1016/j.jhep.2016.02.021) [PubMed]
23. Llovet JM, Bru C, Bruix J 1999. Prognosis of hepatocellular carcinoma: the BCLC staging classification. Semin. Liver Dis. 19, 329–338. (doi:10.1055/s-2007-1007122) [PubMed]
24. European Association for the Study of the Liver, European Organisation for Research and Treatment of Cancer. 2012. EASL-EORTC clinical practice guidelines: management of hepatocellular carcinoma. J. Hepatol. 56, 908–943. (doi:10.1016/j.jhep.2011.12.001) [PubMed]
25. Bruix J, Sherman M, American Association for the Study of Liver Diseases. 2011. Management of hepatocellular carcinoma: an update. Hepatology 53, 1020–1022. (doi:10.1002/hep.24199) [PMC free article] [PubMed]
26. Mazzaferro V, et al. 1996. Liver transplantation for the treatment of small hepatocellular carcinomas in patients with cirrhosis. N. Engl. J. Med. 334, 693–699. (doi:10.1056/NEJM199603143341104) [PubMed]
27. Bruix J, et al. 2017. Regorafenib for patients with hepatocellular carcinoma who progressed on sorafenib treatment (RESORCE): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet 389, 56–66. (doi:10.1016/S0140-6736(16)32453-9) [PubMed]
28. Villanueva A, Hernandez-Gea V, Llovet JM 2013. Medical therapies for hepatocellular carcinoma: a critical view of the evidence. Nat. Rev. Gastroenterol. Hepatol. 10, 34–42. (doi:10.1038/nrgastro.2012.199) [PubMed]
29. Llovet JM, Hernandez-Gea V 2014. Hepatocellular carcinoma: reasons for phase III failure and novel perspectives on trial design. Clin. Cancer Res. 20, 2072–2079. (doi:10.1158/1078-0432.CCR-13-0547) [PubMed]
30. El-Khoueiry AB, et al. 2017. Nivolumab in patients with advanced hepatocellular carcinoma (CheckMate 040): an open-label, non-comparative, phase 1/2 dose escalation and expansion trial. Lancet 389, 2492–2502. (doi:10.1016/S0140-6736(17)31046-2) [PubMed]
31. Krebs K, et al. 2013. T cells expressing a chimeric antigen receptor that binds hepatitis B virus envelope proteins control virus replication in mice. Gastroenterology 145, 456–465. (doi:10.1053/j.gastro.2013.04.047) [PubMed]
32. Chen CJ, Yang HI, Iloeje UH, REVEAL-HBV Study Group 2009. Hepatitis B virus DNA levels and outcomes in chronic hepatitis B. Hepatology 49(Suppl 5), S72–S84. (doi:10.1002/hep.22884) [PubMed]
33. Nakamoto Y, Guidotti LG, Kuhlen CV, Fowler P, Chisari FV 1998. Immune pathogenesis of hepatocellular carcinoma. J. Exp. Med. 188, 341–350. (doi:10.1084/jem.188.2.341) [PMC free article] [PubMed]
34. Buchmann P, et al. 2013. A novel therapeutic hepatitis B vaccine induces cellular and humoral immune responses and breaks tolerance in hepatitis B virus (HBV) transgenic mice. Vaccine 31, 1197–1203. (doi:10.1016/j.vaccine.2012.12.074) [PubMed]
35. Forner A, Llovet JM, Bruix J 2012. Hepatocellular carcinoma. Lancet 379, 1245–1255. (doi:10.1016/S0140-6736(11)61347-0) [PubMed]
36. Jackson SP, Bartek J 2009. The DNA-damage response in human biology and disease. Nature 461, 1071–1078. (doi:10.1038/nature08467) [PMC free article] [PubMed]
37. Chayanupatkul M, Omino R, Mittal S, Kramer JR, Richardson P, Thrift AP, El-Serag HB, Kanwal F 2017. Hepatocellular carcinoma in the absence of cirrhosis in patients with chronic hepatitis B virus infection. J. Hepatol. 66, 355–362. (doi:10.1016/j.jhep.2016.09.013) [PubMed]
38. Bauer T, Sprinzl M, Protzer U 2011. Immune control of hepatitis B virus. Digestion Dis. 29, 423–433. (doi:10.1159/000329809) [PubMed]
39. Chen CJ, et al. 2006. Risk of hepatocellular carcinoma across a biological gradient of serum hepatitis B virus DNA level. J. Am. Med. Assoc. 295, 65–73. (doi:10.1001/jama.295.1.65) [PubMed]
40. Liu J, et al. 2014. Spontaneous seroclearance of hepatitis B seromarkers and subsequent risk of hepatocellular carcinoma. Gut 63, 1648–1657. (doi:10.1136/gutjnl-2013-305785) [PubMed]
41. Buendia MA, Neuveut C 2015. Hepatocellular carcinoma. Cold Spring Harb. Perspect. Med. 5, a021444 (doi:10.1101/cshperspect.a021444) [PMC free article] [PubMed]
42. Sunami Y, et al. 2016. Canonical NF-κB signaling in hepatocytes acts as a tumor-suppressor in hepatitis B virus surface antigen-driven hepatocellular carcinoma by controlling the unfolded protein response. Hepatology 63, 1592–1607. (doi:10.1002/hep.28435) [PubMed]
43. Murakami Y, Saigo K, Takashima H, Minami M, Okanoue T, Brechot C, Paterlini-Bréchot P 2005. Large scaled analysis of hepatitis B virus (HBV) DNA integration in HBV related hepatocellular carcinomas. Gut 54, 1162–1168. (doi:10.1136/gut.2004.054452) [PMC free article] [PubMed]
44. Sung WK, et al. 2012. Genome-wide survey of recurrent HBV integration in hepatocellular carcinoma. Nat. Genet. 44, 765–769. (doi:10.1038/ng.2295) [PubMed]
45. Lau CC, et al. 2014. Viral-human chimeric transcript predisposes risk to liver cancer development and progression. Cancer Cell 25, 335–349. (doi:10.1016/j.ccr.2014.01.030) [PubMed]
46. Ringelhan M, O'Connor T, Protzer U, Heikenwalder M 2015. The direct and indirect roles of HBV in liver cancer: prospective markers for HCC screening and potential therapeutic targets. J. Pathol. 235, 355–367. (doi:10.1002/path.4434) [PubMed]
47. Jors S, et al. 2015. Lineage fate of ductular reactions in liver injury and carcinogenesis. J. Clin. Invest. 125, 2445–2457. (doi:10.1172/JCI78585) [PMC free article] [PubMed]
48. Wang MJ, et al. 2014. Reversal of hepatocyte senescence after continuous in vivo cell proliferation. Hepatology 60, 349–361. (doi:10.1002/hep.27094) [PubMed]
49. Mason WS, et al. 2016. HBV DNA integration and clonal hepatocyte expansion in chronic hepatitis B patients considered immune tolerant. Gastroenterology 151, 986–998, e984. [PubMed]
50. Nassal M. 2015. HBV cccDNA: viral persistence reservoir and key obstacle for a cure of chronic hepatitis B. Gut 64, 1972–1984. (doi:10.1136/gutjnl-2015-309809) [PubMed]
51. Hauer MH, et al. 2017. Histone degradation in response to DNA damage enhances chromatin dynamics and recombination rates. Nat. Struct. Mol. Biol. 24, 99–107. (doi:10.1038/nsmb.3347) [PubMed]
52. Hildt E, Munz B, Saher G, Reifenberg K, Hofschneider PH 2002. The PreS2 activator MHBst of hepatitis B virus activates c-raf-1/Erk2 signaling in transgenic mice. EMBO J. 21, 525–535. (doi:10.1093/emboj/21.4.525) [PubMed]
53. Tropberger P, Mercier A, Robinson M, Zhong W, Ganem DE, Holdorf M 2015. Mapping of histone modifications in episomal HBV cccDNA uncovers an unusual chromatin organization amenable to epigenetic manipulation. Proc. Natl Acad. Sci. USA 112, E5715–E5724. (doi:10.1073/pnas.1518090112) [PubMed]
54. Bouchard MJ, Wang LH, Schneider RJ 2001. Calcium signaling by HBx protein in hepatitis B virus DNA replication. Science 294, 2376–2378. (doi:10.1126/science.294.5550.2376) [PubMed]
55. Lucifora J, Arzberger S, Durantel D, Belloni L, Strubin M, Levrero M, Zoulim F, Hantz O, Protzer U. 2011. Hepatitis B virus X protein is essential to initiate and maintain virus replication after infection. J. Hepatol. 55, 996–1003. (doi:10.1016/j.jhep.2011.02.015) [PubMed]
56. Belloni L, Pollicino T, De Nicola F, Guerrieri F, Raffa G, Fanciulli M, Raimondo G, Levrero M 2009. Nuclear HBx binds the HBV minichromosome and modifies the epigenetic regulation of cccDNA function. Proc. Natl Acad. Sci. USA 106, 19 975–19 979. (doi:10.1073/pnas.0908365106) [PubMed]
57. Riviere L, Gerossier L, Ducroux A, Dion S, Deng Q, Michel ML, Buendia MA, Hantz O, Neuveut C 2015. HBx relieves chromatin-mediated transcriptional repression of hepatitis B viral cccDNA involving SETDB1 histone methyltransferase. J. Hepatol. 63, 1093–1102. (doi:10.1016/j.jhep.2015.06.023) [PubMed]
58. Li T, Robert EI, van Breugel PC, Strubin M, Zheng N 2010. A promiscuous α-helical motif anchors viral hijackers and substrate receptors to the CUL4-DDB1 ubiquitin ligase machinery. Nat. Struct. Mol. Biol. 17, 105–111. (doi:10.1038/nsmb.1719) [PMC free article] [PubMed]
59. Decorsiere A, et al. 2016. Hepatitis B virus X protein identifies the Smc5/6 complex as a host restriction factor. Nature 531, 386–389. (doi:10.1038/nature17170) [PubMed]
60. Menolfi D, Delamarre A, Lengronne A, Pasero P, Branzei D 2015. Essential roles of the Smc5/6 complex in replication through natural pausing sites and endogenous DNA damage tolerance. Mol. Cell 60, 835–846. (doi:10.1016/j.molcel.2015.10.023) [PMC free article] [PubMed]
61. Llovet JM, Zucman-Rossi J, Pikarsky E, Sangro B, Schwartz M, Sherman M, Gores G 2016. Hepatocellular carcinoma. Nat. Rev. Dis. Primers 2, 16018 (doi:10.1038/nrdp.2016.18) [PubMed]
62. Cornella H, et al. 2015. Unique genomic profile of fibrolamellar hepatocellular carcinoma. Gastroenterology 148, 806 (doi:10.1053/j.gastro.2014.12.028) [PMC free article] [PubMed]
63. Schulze K, et al. 2015. Exome sequencing of hepatocellular carcinomas identifies new mutational signatures and potential therapeutic targets. Nat. Genet. 47, 505–511. (doi:10.1038/ng.3252) [PMC free article] [PubMed]
64. Ochi Y, et al. 2017. HLA-DQ gene polymorphisms are associated with hepatocellular carcinoma and hepatitis B surface antigen in chronic hepatitis B virus infection. Hepatol. Res. 47, 755–766. (doi:10.1111/hepr.12812) [PubMed]
65. Zucman-Rossi J, Villanueva A, Nault JC, Llovet JM 2015. Genetic landscape and biomarkers of hepatocellular carcinoma. Gastroenterology 149, 1226 (doi:10.1053/j.gastro.2015.05.061) [PubMed]
66. Wang B, Huang G, Wang D, Li A, Xu Z, Dong R, Zhang D, Zhou W 2010. Null genotypes of GSTM1 and GSTT1 contribute to hepatocellular carcinoma risk: evidence from an updated meta-analysis. J. Hepatol. 53, 508–518. (doi:10.1016/j.jhep.2010.03.026) [PubMed]
67. Yoon YJ, et al. 2008. MDM2 and p53 polymorphisms are associated with the development of hepatocellular carcinoma in patients with chronic hepatitis B virus infection. Carcinogenesis 29, 1192–1196. (doi:10.1093/carcin/bgn090) [PubMed]
68. Long XD, Ma Y, Qu DY, Liu YG, Huang ZQ, Huang YZ, Lin ZH, Wei NB, Zhou SC 2008. The polymorphism of XRCC3 codon 241 and AFB1-related hepatocellular carcinoma in Guangxi population, China. Ann. Epidemiol. 18, 572–578. (doi:10.1016/j.annepidem.2008.03.003) [PubMed]
69. Gu X, Qi P, Zhou F, Ji Q, Wang H, Dou T, Zhao Y, Gao C 2010. +49G > A polymorphism in the cytotoxic T-lymphocyte antigen-4 gene increases susceptibility to hepatitis B-related hepatocellular carcinoma in a male Chinese population. Hum. Immunol. 71, 83–87. (doi:10.1016/j.humimm.2009.09.353) [PubMed]
70. Wang WT, Li Z, Shi M, Zhu H, Xiong X, Shang J, Liu J, Teng M, Yang M 2016. Association of the GLB1 rs4678680 genetic variant with risk of HBV-related hepatocellular carcinoma. Oncotarget 7, 56 501–56 507. (doi:10.18632/oncotarget.10963) [PMC free article] [PubMed]
71. Migita K, et al. 2005. Cytokine gene polymorphisms in Japanese patients with hepatitis B virus infection—association between TGF-β1 polymorphisms and hepatocellular carcinoma. J. Hepatol. 42, 505–510. (doi:10.1016/j.jhep.2004.11.026) [PubMed]
72. Kumar V, et al. 2011. Genome-wide association study identifies a susceptibility locus for HCV-induced hepatocellular carcinoma. Nat. Genet. 43, 455–458. (doi:10.1038/ng.809) [PubMed]
73. Miki D, et al. 2011. Variation in the DEPDC5 locus is associated with progression to hepatocellular carcinoma in chronic hepatitis C virus carriers. Nat. Genet. 43, 797–800. (doi:10.1038/ng.876) [PubMed]
74. Burza MA, et al. 2016. DEPDC5 variants increase fibrosis progression in Europeans with chronic hepatitis C virus infection. Hepatology 63, 418–427. (doi:10.1002/hep.28322) [PMC free article] [PubMed]
75. Cleary SP, et al. 2013. Identification of driver genes in hepatocellular carcinoma by exome sequencing. Hepatology 58, 1693–1702. (doi:10.1002/hep.26540) [PMC free article] [PubMed]
76. Nault JC, Calderaro J, Di Tommaso L, Balabaud C, Zafrani ES, Bioulac-Sage P, Roncalli M, Zucman-Rossi J 2014. Telomerase reverse transcriptase promoter mutation is an early somatic genetic alteration in the transformation of premalignant nodules in hepatocellular carcinoma on cirrhosis. Hepatology 60, 1983–1992. (doi:10.1002/hep.27372) [PubMed]
77. Ray RB, Meyer K, Ray R 2000. Hepatitis C virus core protein promotes immortalization of primary human hepatocytes. Virology 271, 197–204. (doi:10.1006/viro.2000.0295) [PubMed]
78. Nault JC, Zucman-Rossi J 2016. TERT promoter mutations in primary liver tumors. Clin. Res. Hepatol. Gastroenterol. 40, 9–14. (doi:10.1016/j.clinre.2015.07.006) [PubMed]
79. Raimondi S, Bruno S, Mondelli MU, Maisonneuve P 2009. Hepatitis C virus genotype 1b as a risk factor for hepatocellular carcinoma development: a meta-analysis. J. Hepatol. 50, 1142–1154. (doi:10.1016/j.jhep.2009.01.019) [PubMed]
80. Kanwal F, Kramer JR, Ilyas J, Duan Z, El-Serag HB 2014. HCV genotype 3 is associated with an increased risk of cirrhosis and hepatocellular cancer in a national sample of U.S. veterans with HCV . Hepatology 60, 98–105. (doi:10.1002/hep.27095) [PMC free article] [PubMed]
81. Akuta N, et al. 2015. Impact of mutations at amino acid 70 in hepatitis C virus (HCV) genotype 1b core region on hepatocarcinogenesis following eradication of HCV RNA. J. Clin. Microbiol. 53, 3039–3041. (doi:10.1128/JCM.01457-15) [PMC free article] [PubMed]
82. El-Shamy A, Pendleton M, Eng FJ, Doyle EH, Bashir A, Branch AD 2016. Impact of HCV core gene quasispecies on hepatocellular carcinoma risk among HALT-C trial patients. Sci. Rep. 6, 27025 (doi:10.1038/srep27025) [PMC free article] [PubMed]
83. Goossens N, Negro F 2014. Insulin resistance, non-alcoholic fatty liver disease and hepatitis C virus infection. Rev. Recent Clin. Trials 9, 204–209. (doi:10.2174/1574887109666141216101939) [PubMed]
84. Miyamoto H, Moriishi K, Moriya K, Murata S, Tanaka K, Suzuki T, Miyamura T, Koike K, Matsuura Y 2007. Involvement of the PA28γ-dependent pathway in insulin resistance induced by hepatitis C virus core protein. J. Virol. 81, 1727–1735. (doi:10.1128/JVI.01683-06) [PMC free article] [PubMed]
85. Bernsmeier C, Calabrese D, Heim MH, Duong HT 2014. Hepatitis C virus dysregulates glucose homeostasis by a dual mechanism involving induction of PGC1α and dephosphorylation of FoxO1. J. Viral Hepat. 21, 9–18. (doi:10.1111/jvh.12208) [PubMed]
86. Hara Y, et al. 2014. Hepatitis C virus core protein suppresses mitophagy by interacting with parkin in the context of mitochondrial depolarization. Am. J. Pathol. 184, 3026–3039. (doi:10.1016/j.ajpath.2014.07.024) [PubMed]
87. Moriya K, et al. 2001. Oxidative stress in the absence of inflammation in a mouse model for hepatitis C virus-associated hepatocarcinogenesis. Cancer Res. 61, 4365–4370. [PubMed]
88. Thorgeirsson SS, Grisham JW 2002. Molecular pathogenesis of human hepatocellular carcinoma. Nat. Genet. 31, 339–346. (doi:10.1038/ng0802-339) [PubMed]
89. Gong G, Waris G, Tanveer R, Siddiqui A 2001. Human hepatitis C virus NS5A protein alters intracellular calcium levels, induces oxidative stress, and activates STAT-3 and NF-κB. Proc. Natl Acad. Sci. USA 98, 9599–9604. (doi:10.1073/pnas.171311298) [PubMed]
90. Korenaga M, Wang T, Li Y, Showalter LA, Chan T, Sun J, Weinman SA 2005. Hepatitis C virus core protein inhibits mitochondrial electron transport and increases reactive oxygen species (ROS) production. J. Biol. Chem. 280, 37 481–37 488. (doi:10.1074/jbc.M506412200) [PubMed]
91. Okuda M, Li K, Beard MR, Showalter LA, Scholle F, Lemon SM, Weinman SA 2002. Mitochondrial injury, oxidative stress, and antioxidant gene expression are induced by hepatitis C virus core protein. Gastroenterology 122, 366–375. (doi:10.1053/gast.2002.30983) [PubMed]
92. Ariumi Y, Kuroki M, Dansako H, Abe K, Ikeda M, Wakita T, Kato N 2008. The DNA damage sensors ataxia-telangiectasia mutated kinase and checkpoint kinase 2 are required for hepatitis C virus RNA replication. J. Virol. 82, 9639–9646. (doi:10.1128/JVI.00351-08) [PMC free article] [PubMed]
93. Lai CK, Jeng KS, Machida K, Cheng YS, Lai MM 2008. Hepatitis C virus NS3/4A protein interacts with ATM, impairs DNA repair and enhances sensitivity to ionizing radiation. Virology 370, 295–309. (doi:10.1016/j.virol.2007.08.037) [PubMed]
94. Machida K, McNamara G, Cheng KT, Huang J, Wang CH, Comai L, Ou JH, Lai MM 2010. Hepatitis C virus inhibits DNA damage repair through reactive oxygen and nitrogen species and by interfering with the ATM-NBS1/Mre11/Rad50 DNA repair pathway in monocytes and hepatocytes. J. Immunol. 185, 6985–6998. (doi:10.4049/jimmunol.1000618) [PMC free article] [PubMed]
95. Harouaka D, et al. 2016. Diminished viral replication and compartmentalization of hepatitis C virus in hepatocellular carcinoma tissue. Proc. Natl Acad. Sci. USA 113, 1375–1380. (doi:10.1073/pnas.1516879113) [PubMed]
96. Munakata T, Liang Y, Kim S, McGivern DR, Huibregtse J, Nomoto A, Lemon SM 2007. Hepatitis C virus induces E6AP-dependent degradation of the retinoblastoma protein. PLoS Pathog. 3, 1335–1347. (doi:10.1371/journal.ppat.0030139) [PMC free article] [PubMed]
97. Munakata T, Nakamura M, Liang Y, Li K, Lemon SM 2005. Down-regulation of the retinoblastoma tumor suppressor by the hepatitis C virus NS5B RNA-dependent RNA polymerase. Proc. Natl Acad. Sci. USA 102, 18 159–18 164. (doi:10.1073/pnas.0505605102) [PubMed]
98. Arora P, Basu A, Schmidt ML, Clark GJ, Donninger H, Nichols DB, Calvisi DF, Kaushik-Basu N 2017. NS5B promotes degradation of the NORE1A tumor suppressor to facilitate hepatitis C virus replication. Hepatology 65, 1462–1477. (doi:10.1002/hep.29049) [PubMed]
99. Guichard C, et al. 2012. Integrated analysis of somatic mutations and focal copy-number changes identifies key genes and pathways in hepatocellular carcinoma. Nat. Genet. 44, 694–698. (doi:10.1038/ng.2256) [PMC free article] [PubMed]
100. McGivern DR, Lemon SM 2011. Virus-specific mechanisms of carcinogenesis in hepatitis C virus associated liver cancer. Oncogene 30, 1969–1983. (doi:10.1038/onc.2010.594) [PMC free article] [PubMed]
101. Hsu IC, Tokiwa T, Bennett W, Metcalf RA, Welsh JA, Sun T, Harris CC 1993. p53 gene mutation and integrated hepatitis B viral DNA sequences in human liver cancer cell lines. Carcinogenesis 14, 987–992. (doi:10.1093/carcin/14.5.987) [PubMed]
102. Kofahi HM, Taylor NG, Hirasawa K, Grant MD, Russell RS 2016. Hepatitis C virus infection of cultured human hepatoma cells causes apoptosis and pyroptosis in both infected and bystander cells. Sci. Rep. 6, 37433 (doi:10.1038/srep37433) [PMC free article] [PubMed]
103. Benhenda S, et al. 2013. Methyltransferase PRMT1 is a binding partner of HBx and a negative regulator of hepatitis B virus transcription. J. Virol. 87, 4360–4371. (doi:10.1128/JVI.02574-12) [PMC free article] [PubMed]
104. Bartsch H, Nair J 2006. Chronic inflammation and oxidative stress in the genesis and perpetuation of cancer: role of lipid peroxidation, DNA damage, and repair. Langenbecks Arch. Surg. 391, 499–510. (doi:10.1007/s00423-006-0073-1) [PubMed]
105. Nakagawa S, et al. 2016. Molecular liver cancer prevention in cirrhosis by organ transcriptome analysis and lysophosphatidic acid pathway inhibition. Cancer Cell 30, 879–890. (doi:10.1016/j.ccell.2016.11.004) [PubMed]
106. Knowlden S, Georas SN 2014. The autotaxin-LPA axis emerges as a novel regulator of lymphocyte homing and inflammation. J. Immunol. 192, 851–857. (doi:10.4049/jimmunol.1302831) [PMC free article] [PubMed]
107. Farquhar MJ, et al. 2017. Autotaxin-lysophosphatidic acid receptor signalling regulates hepatitis C virus replication. J. Hepatol. 66, 919–929. (doi:10.1016/j.jhep.2017.01.009) [PubMed]
108. Shih YL, Kuo CC, Yan MD, Lin YW, Hsieh CB, Hsieh TY 2016. Quantitative methylation analysis reveals distinct association between PAX6 methylation and clinical characteristics with different viral infections in hepatocellular carcinoma. Clin. Epigenetics 8, 41 (doi:10.1186/s13148-016-0208-3) [PMC free article] [PubMed]
109. Okamoto Y, et al. 2014. Hepatitis virus infection affects DNA methylation in mice with humanized livers. Gastroenterology 146, 562–572. (doi:10.1053/j.gastro.2013.10.056) [PubMed]
110. Wijetunga NA, Pascual M, Tozour J, Delahaye F, Alani M, Adeyeye M, Wolkoff AW, Verma A, Greally JM 2016. A pre-neoplastic epigenetic field defect in HCV-infected liver at transcription factor binding sites and polycomb targets. Oncogene 36, 2030–2044. (doi:10.1038/onc.2016.340) [PMC free article] [PubMed]
111. Wilson GK, et al. 2012. A dual role for hypoxia inducible factor-1α in the hepatitis C virus lifecycle and hepatoma migration. J. Hepatol. 56, 803–809. (doi:10.1016/j.jhep.2011.11.018) [PMC free article] [PubMed]
112. Nasimuzzaman M, Waris G, Mikolon D, Stupack DG, Siddiqui A 2007. Hepatitis C virus stabilizes hypoxia-inducible factor 1α and stimulates the synthesis of vascular endothelial growth factor. J. Virol. 81, 10 249–10 257. (doi:10.1128/JVI.00763-07) [PMC free article] [PubMed]
113. Murakami Y, Kawada N 2017. MicroRNAs in hepatic pathophysiology. Hepatol. Res. 47, 60–69. (doi:10.1111/hepr.12730) [PubMed]
114. Hayes CN, Chayama K 2016. MicroRNAs as biomarkers for liver disease and hepatocellular carcinoma. Int. J. Mol. Sci. 17, 280 (doi:10.3390/ijms17030280) [PMC free article] [PubMed]
115. Selitsky SR, et al. 2015. Transcriptomic analysis of chronic hepatitis B and C and liver cancer reveals microRNA-mediated control of cholesterol synthesis programs. mBio 6, e01500-15. (doi:10.1128/mBio.01500-15) [PMC free article] [PubMed]
116. Qi P, Dou TH, Geng L, Zhou FG, Gu X, Wang H, Gao CF 2010. Association of a variant in MIR 196A2 with susceptibility to hepatocellular carcinoma in male Chinese patients with chronic hepatitis B virus infection. Hum. Immunol. 71, 621–626. (doi:10.1016/j.humimm.2010.02.017) [PubMed]
117. Yuan K, Lian ZR, Sun B, Clayton MM, Ng IOL, Feitelson MA 2012. Role of miR-148a in hepatitis B associated hepatocellular carcinoma. PLoS ONE 7, e35331 (doi:10.1371/journal.pone.0035331) [PMC free article] [PubMed]
118. Arzumanyan A, Reis HM, Feitelson MA 2013. Pathogenic mechanisms in HBV- and HCV-associated hepatocellular carcinoma. Nat. Rev. Cancer 13, 123–135. (doi:10.1038/nrc3449) [PubMed]
119. Bandiera S, et al. 2016. Hepatitis C virus-induced upregulation of microRNA miR-146a-5p in hepatocytes promotes viral infection and deregulates metabolic pathways associated with liver disease pathogenesis. J. Virol. 90, 6387–6400. (doi:10.1128/JVI.00619-16) [PMC free article] [PubMed]
120. Xu H, Li G, Yue Z, Li C 2016. HCV core protein-induced upregulation of microRNA-196a promotes aberrant proliferation in hepatocellular carcinoma by targeting FOXO1. Mol. Med. Rep. 13, 5223–5229. [PubMed]
121. Spaniel C, Honda M, Selitsky SR, Yamane D, Shimakami T, Kaneko S, Lanford RE, Lemon SM 2013. MicroRNA-122 abundance in hepatocellular carcinoma and non-tumor liver tissue from Japanese patients with persistent HCV versus HBV infection. PLoS ONE 8, e76867 (doi:10.1371/journal.pone.0076867) [PMC free article] [PubMed]
122. Hoh A, et al. 2015. HBV-infected HepG2hNTCP cells serve as a novel immunological tool to analyze the antiviral efficacy of CD8+ T cells in vitro. J. Virol. 89, 7433–7438. (doi:10.1128/JVI.00605-15) [PMC free article] [PubMed]
123. Papatheodoridis GV, Lampertico P, Manolakopoulos S, Lok A 2010. Incidence of hepatocellular carcinoma in chronic hepatitis B patients receiving nucleos(t)ide therapy: a systematic review. J. Hepatol. 53, 348–356. (doi:10.1016/j.jhep.2010.02.035) [PubMed]
124. Bohne F, et al. 2014. HCV-induced immune responses influence the development of operational tolerance after liver transplantation in humans. Sci. Transl. Med. 6, 242ra81 (doi:10.1126/scitranslmed.3008793) [PubMed]
125. Di Marco V, et al. 2016. Effects of eradicating hepatitis C virus infection in patients with cirrhosis differ with stage of portal hypertension. Gastroenterology 151, 130–139. (doi:10.1053/j.gastro.2016.03.036) [PubMed]
126. Nahon P, et al. 2017. Eradication of hepatitis C virus infection in patients with cirrhosis reduces risk of liver and non-liver complications. Gastroenterology 152, 142–156. (doi:10.1053/j.gastro.2016.09.009) [PubMed]
127. van der Meer AJ, et al. 2017. Risk of cirrhosis-related complications in patients with advanced fibrosis following hepatitis C virus eradication. J. Hepatol. 66, 485–493. (doi:10.1016/j.jhep.2016.10.017) [PubMed]
128. Ganne-Carrie N, et al. 2016. Nomogram for individualized prediction of hepatocellular carcinoma occurrence in hepatitis C virus cirrhosis (ANRS CO12 CirVir). Hepatology 64, 1136–1147. (doi:10.1002/hep.28702) [PubMed]
129. Reig M, et al. 2016. Unexpected high rate of early tumor recurrence in patients with HCV-related HCC undergoing interferon-free therapy. J. Hepatol. 65, 719–726. (doi:10.1016/j.jhep.2016.04.008) [PubMed]
130. Cheung MC, et al. 2016. Outcomes after successful direct-acting antiviral therapy for patients with chronic hepatitis C and decompensated cirrhosis. J. Hepatol. 65, 741–747. (doi:10.1016/j.jhep.2016.06.019) [PubMed]
131. Morgan RL, Baack B, Smith BD, Yartel A, Pitasi M, Falck-Ytter Y 2013. Eradication of hepatitis C virus infection and the development of hepatocellular carcinoma: a meta-analysis of observational studies. Ann. Intern. Med. 158, 329–337. (doi:10.7326/0003-4819-158-5-201303050-00005) [PubMed]
132. ANRS collaborative study group on hepatocellular carcinoma. 2016. Lack of evidence of an effect of direct-acting antivirals on the recurrence of hepatocellular carcinoma: data from three ANRS cohorts. J. Hepatol. 65, 734–740. (doi:10.1016/j.jhep.2016.05.045) [PubMed]
133. El-Serag HB, Kanwal F, Richardson P, Kramer J 2016. Risk of hepatocellular carcinoma after sustained virological response in veterans with hepatitis C virus infection. Hepatology 64, 130–137. (doi:10.1002/hep.28535) [PMC free article] [PubMed]
134. Zhang BH, Yang BH, Tang ZY 2004. Randomized controlled trial of screening for hepatocellular carcinoma. J. Cancer Res. Clin. Oncol. 130, 417–422. (doi:10.1007/s00432-004-0552-0) [PubMed]
135. Yeh YP, et al. 2014. Evaluation of abdominal ultrasonography mass screening for hepatocellular carcinoma in Taiwan. Hepatology 59, 1840–1849. (doi:10.1002/hep.26703) [PMC free article] [PubMed]
136. International Consensus Group for Hepatocellular Neoplasia. 2009. Pathologic diagnosis of early hepatocellular carcinoma: a report of the International Consensus Group for Hepatocellular Neoplasia. Hepatology 49, 658–664. (doi:10.1002/hep.22709) [PubMed]
137. Han KH, Kim DY, Park JY, Ahn SH, Kim J, Kim SU, Kim JK, Lee KS, Chon CY 2013. Survival of hepatocellular carcinoma patients may be improved in surveillance interval not more than 6 months compared with more than 6 months: a 15-year prospective study. J. Clin. Gastroenterol. 47, 538–544. (doi:10.1097/MCG.0b013e3182755c13) [PubMed]

Articles from Philosophical Transactions of the Royal Society B: Biological Sciences are provided here courtesy of The Royal Society