Genotypes, mutations, and viral load of hepatitis B virus and the risk of hepatocellular carcinoma: HBV properties and hepatocarcinogenesis

Chronic infection with hepatitis B virus (HBV) is the major risk factor for hepatocellular carcinoma (HCC) worldwide. Ten HBV genotypes (A-J) have been discovered so far. Genotypes B and C are endemic in East and Southeast Asia. Genotype C HBV is associated with increased risks of cirrhosis and HCC. Genotype B (B2) is associated with the development of HCC in non-cirrhotic patients younger than 50 years and with relapse of HCC after surgical treatment. It is also associated with earlier hepatitis B e antigen seroconversion than genotype C. High HBV load is independently associated with the occurrence and post-treatment recurrence of HCC. Different genotypes have distinct patterns of mutations. Viral mutations in the core promoter region and in the preS region are frequently found to be significantly associated with an increased risk of HCC. These mutations often occur before the onset of HCC and accumulate during the progression of chronic HBV infection. Multiple such mutations are more frequent in patients with HCC and are specific for HCC. HBV subgenotypes, viral mutations, and viral load can be used for the prediction of HCC. Early identification of HBV-infected individuals who will eventually develop HCC will help to develop active prophylactic protocols to reduce or delay the occurrence of HCC.     

Genomic change in hepatitis B virus associated with development of hepatocellular carcinoma

AIM: To determine the genomic changes in hepatitis B virus (HBV) and evaluate their role in the development of hepatocellular carcinoma (HCC) in patients chronically infected with genotype C HBV.METHODS: Two hundred and forty chronic hepatitis B (CHB) patients were subjected and followed for a median of 105 mo. HCC was diagnosed in accordance with AASLD guidelines. The whole X, S, basal core promoter (BCP), and precore regions of HBV were sequenced using the direct sequencing method.RESULTS: All of the subjects were infected with genotype C HBV. Out of 240 CHB patients, 25 (10%) had C1653T and 33 (14%) had T1753V mutation in X region; 157 (65%) had A1762T/G1764A mutations in BCP region, 50 (21%) had G1896A mutation in precore region and 67 (28%) had pre-S deletions. HCC occurred in 6 patients (3%). The prevalence of T1753V mutation was significantly higher in patients who developed HCC than in those without HCC. The cumulative occurrence rates of HCC were 5% and 19% at 10 and 15 years, respectively, in patients with T1753V mutant, which were significantly higher than 1% and 1% in those with wild type HBV (P < 0.001).CONCLUSION: The presence of T1753V mutation in HBV X-gene significantly increases the risk of HCC development in patients chronically infected with genotype C HBV.     

Molecular mechanisms of viral hepatitis induced hepatocellular carcinoma

Chronic infection with viral hepatitis affects half a billion individuals worldwide and can lead to cirrhosis, cancer, and liver failure. Liver cancer is the third leading cause of cancer-associated mortality, of which hepatocellular carcinoma (HCC)represents 90%of all primary liver cancers. Solid tumors like HCC are complex and have heterogeneous tumor genomic profiles contributing to complexity in diagnosis and management. Chronic infection with hepatitis B virus (HBV),hepatitis delta virus (HDV), and hepatitis C virus (HCV) are the greatest etiological risk factors for HCC. Due to the significant role of chronic viral infection in HCC development, it is important to investigate direct (viral associated) and indirect (immune-associated) mechanisms involved in the pathogenesis of HCC. Common mechanisms used by HBV, HCV, and HDV that drive hepatocarcinogenesis include persistent liver inflammation with an impaired antiviral immune response, immune and viral protein-mediated oxidative stress, and deregulation of cellular signaling pathways by viral proteins.DNA integration to promote genome instability is a feature of HBV infection, and metabolic reprogramming leading to steatosis is driven by HCV infection. The current review aims to provide a brief overview of HBV, HCV and HDV molecular biology, and highlight specific viral-associated oncogenic mechanisms and common molecular pathways deregulated in HCC, and current as well as emerging treatments for HCC.     

Prevention of hepatocellular carcinoma in chronic viral hepatitis B and C infection

Hepatocellular carcinoma(HCC)is a leading cause of cancer-related mortality worldwide,with the majority of cases associated with persistent infection from hepatitis B virus(HBV)or hepatitis C virus(HCV).Natural history studies have identified risk factors associated with HCC development among chronic HBV and HCV infection.High-risk infected individuals can now be identified by the usage of risk predictive scores.Vaccination plays a central role in the prevention of HBV-related HCC.Treatment of chronic HBV infection,especially by nucleoside analogue therapy,could also reduce the risk of HBV-related HCC.Concerning HCV infection,besides the advocation of universal precautions to reduce the rate of infection,pegylated interferon and ribavirin could also reduce the risk of HCV-related HCC among those achieving a sustained virologic response.Recently there has been mounting evidence on the role of chemopreventive agents in reducing HBV-and HCV-related HCC.The continued advances in the understanding of the molecular pathogenesis of HCC would hold promise in preventing this highly lethal cancer.     

Occult hepatitis B virus and hepatocellular carcinoma

Occult hepatitis B virus (HBV) infection (OBI) is a challenging pathobiological and clinical issue that has been widely debated for several decades. By definition, OBI is characterized by the persistence of HBV DNA in the liver tissue (and in some cases also in the serum) in the absence of circulating HBV surface antigen (HBsAg). Many epidemiological and molecular studies have indicated that OBI is an important risk factor for hepatocellular carcinoma (HCC) development. OBI may exert direct pro-oncogenic effects through the activation of the same oncogenic mechanisms that are activated in the course of an HBsAg-positive infection. Indeed, in OBI as in HBV-positive infection, HBV DNA can persist in the hepatocytes both integrated into the host genome as well as free episome, and may maintain the capacity to produce proteins-mainly X protein and truncated preS-S protein - provided with potential transforming properties. Furthermore, OBI may indirectly favor HCC development. It has been shown that the persistence of very low viral replicative activity during OBI may induce mild liver necro-inflammation continuing for life, and substantial clinical evidence indicates that OBI can accelerate the progression of liver disease towards cirrhosis that is considered the most important risk factor for HCC development.     

RECK gene polymorphisms in hepatitis B-related hepatocellular carcinoma: A case-control study

Background and study aimsChronic hepatitis B (CHB) infection is a major risk factor for hepatocellular carcinoma (HCC). The RECK gene is a critical tumor suppressor gene. This study aimed to assess the association between RECK gene single nucleotide polymorphisms (SNPs) and the development of HCC in Egyptian patients with chronic hepatitis B.Patients and methodIn this case-control study, we enrolled patients with CHB from the Gastroenterology Department, Benha University, from June 2016 to February 2018. The RECK gene SNP rs10814325 was identified using real-time PCR allelic discrimination via TaqMan SNP genotyping assays (Applied Biosystems, USA).ResultsWe enrolled 140 participants in this study. The participants were divided into Group I, which comprised 50 participants with CHB only, Group II, which comprised 50 participants with CHB and HCC, and Group III, which comprised 40 healthy participants. A significantly higher hepatitis B virus DNA viremia level was found in patients with HCC. The predominant RECK genotype was the T/T allele, followed by the T/C allele; however, no significant difference in the distribution of RECK gene SNPs was found between the study groups. No statistically significant difference in RECK gene SNPs was reported among patients with HCC of different Child classes or based on the number, site, size of HCC, and lymph node involvement. Receiver operating characteristic curves showed that a serum alpha-fetoprotein level of 92 ng/ml was 96 % sensitive and 100 % specific for the detection of HCC, with an area under the operating characteristic curve of 0.98.ConclusionRECK gene SNPs have no significant association with the development and characteristics of hepatitis B-related HCC in Egyptian patients.     

Clinical features of hepatitis B virus-related hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a major cause of cancer death,and chronic hepatitis B is a serious worldwide problem.The epidemiology of HCC is distinctive.Hepatitis B virus (HBV) plays a major role in hepatocarcinogenesis.Prevention of HBV-related HCC is a key issue in current hepatology.This paper describes the prevention and clinical features of HBVrelated HCC,along with a short review of the disease.     

Factors predicting occurrence and prognosis of hepatitis-B-virus-related hepatocellular carcinoma

Primary liver cancer is an important cause of cancer death,and hepatocellular carcinoma(HCC) accounts for 70%-85% of total liver cancer worldwide.Chronic hepatitis B virus(HBV) infection contributes to > 75% of HCC cases.High serum viral load is the most reliable indicator of viral replication in predicting development of HCC.HBV genotype C is closely associated with HCC in cirrhotic patients aged > 50 years,whereas genotype B is associated with development of HCC in non-cirrhotic young patients and postope...     

Key role of hepatitis B virus mutation in chronic hepatitis B development to hepatocellular carcinoma

Chronic hepatitis B virus (HBV) infection is a major risk factor for hepatocellular carcinoma (HCC). The HBV mutations, which include point mutation, deletion, insertion and truncation mutation of HBV gene in 4 open reading frames (S, C, P, X), are closely associated with HCC pathogenesis. Some mutations accumulated during chronic HBV infection could be regarded as a biomarker to predict the occurrence of HCC. The detection of the mutations in clinical practice could be helpful for defining better preventive and therapeutic strategies and, moreover, predicting the progression of liver disease.     

Latent hepatitis B is a risk factor for hepatocellular carcinoma in patients with chronic hepatitis C

AIM:To study the potential association between hepatocellular carcinoma(HCC)in patients with chronic hepatitis C(CHC),cirrhosis and latent hepatitis B(LHB)infection,defined as the absence of detectable serum hepatitis B surface antigen(HBsAg)and the presence of hepatitis B core antibody(HBcAb).METHODS:This retrospective analysis is comprised of 185 cirrhotic patients with HCC who were hepatitis C virus antibody(HCV Ab)(+)and HBsAg(-)at Wayne State University between 1999 and 2008.From these,108 patients had HCV polymerase chain reaction confirmation of viremia while the remaining(77)were considered to have CHC on the basis of a positive HCV Ab and the absence of any other cause of liver disease.Controls were drawn from our institutional database from the same time period and consisted of 356 HBsAg(-)age,race and gender matched patients with HCV RNA-confirmed CHC and without evidence of HCC.A subgroup of controls included 118matched patients with liver cirrhosis.χ2test and t test were used for data analysis.RESULTS:Seventy-seven percent of patients in all3 groups were African Americans.Patients with HCC had a significantly higher body mass index(P=0.03),a higher rate of co-infection with human immunodeficiency virus(HIV)(P=0.05)and a higher prevalence of alcohol abuse(P=0.03)than the controls.More patients with HCC had LHB than controls(78%vs39%,P=0.01).Sixty three percent of patients with HCC were both hepatitis B surface antigen(HBsAb)(-)and HBcAb(+)compared to 23%of controls(P<0.01).When compared to cirrhotic controls,the frequency of HBcAb(+)remained higher in patients with HCC(78%vs 45%,P=0.02).Patients with HCC were more likely to be both HBsAb(-)and HBcAb(+)than the cirrhotic controls(63%vs 28%,P=0.01).Although not statistically significant,100%of CHC and HIV coinfected patients with HCC(n=11)were HBcAb(+)when compared to controls(44%;n=9).CONCLUSION:These data suggest that LHB occurs at a significantly increased frequency in patients with CHC and HCC than in patients with CHC without HCC.     

High-dose hepatitis B immunoglobulin therapy in hepatocellular carcinoma with hepatitis B virus-DNA/hepatitis B e antigen-positive patients after living donor liver transplantation

AIM: To investigate the impact of high-dose hepatitis B immunoglobulin(HBIG) on hepatocellular carcinoma(HCC) and hepatitis B virus(HBV) recurrence and overall survival after living donor liver transplantation(LDLT).METHODS: We investigated 168 patients who underwent LDLT due to HCC, and who were HBV-DNA/hepatitis B e antigen(HBe Ag)-positive, from January 2008 to December 2013. After assessing whether the patients met the Milan criteria, they were assigned to the low-dose HBIG group and high-dose HBIG group. Using the propensity score 1:1 matching method, 38 and 18 pairs were defined as adhering to and not adhering to the Milan criteria. For each pair, HCC recurrence, HBV recurrence and overall survival were analyzed by the Kaplan-Meier method and the log rank test according to the HBIG dose. RESULTS: Among those who met the Milan criteria, the 6-mo, 1-year, and 3-year HCC recurrence-free survival rates were 88.9%, 83.2%, and 83.2% in the low-dose HBIG group and 97.2%, 97.2%, and 97.2% in the high-dose HBIG group, respectively(P = 0.042).In contrast, among those who did not meet the Milan criteria, HCC recurrence did not differ according to the HBIG dose(P = 0.937). Moreover, HBV recurrence and overall survival did not differ according to the HBIG dose among those who met(P = 0.317 and 0.190, respectively) and did not meet(P = 0.350 and 0.987, respectively) the Milan criteria. CONCLUSION: High-dose HBIG therapy can reduce HCC recurrence in HBV-DNA/HBe Ag-positive patients after LDLT.     

乙型肝炎和肝癌患者乙型肝炎病毒前C区1896位点突变的研究

为探索乙型肝炎病毒前Ｃ区突变是否与肝损程度及肝癌发生有关，对１３９例ＨＢｓＡｇ、ＨＢＶＤＮＡ和抗－ＨＢｅ阳性，ＨＢｅＡｇ阴性的慢性ＨＢＶ感染者和肝癌患者的血清标本，采用３＇碱基特异性聚合酶反应进行了第１８９６位核苷酸突变的检测分析。     

血清HBV DNA与肝动脉化疗栓塞术后肝癌复发的相关性研究

目的观察肝癌患者血清HBV DNA载量与肝动脉化疗栓塞术(TACE)后肿瘤复发的关系。方法检测193例乙型肝炎病毒标记物阳性的肝癌患者在TACE治疗前血清HBV DNA载量,分析患者血清HBV DNA载量与栓塞术后肿瘤复发的关系。结果在193例患者中,介入治疗术后2年内共有169例(87.6%)患者肿瘤复发;血清HBV DNA阳性(≥5×102copies/ml)138例,平均血清病毒载量为6.20±1.12lg copies/ml;单因素及多因素分析显示,肝功能Child-Pugh B级或C级、多发肿瘤、肿瘤最长径大于3cm、血清HBV DNA≥5×102copies/ml患者肿瘤复发的相对危险性较高,无肿瘤复发生存期较短。结论肝癌患者血清HBV DNA≥5×102copies/ml是TACE治疗后肿瘤复发的危险因素之一。     

Risk calculators for hepatocellular carcinoma in patients affected with chronic hepatitis B in Asia

Risk calculators are widely used in many clinical fields, and integrate several important risk factors through the conversion of a risk function into a single measure of risk. Several studies have been carried out to create risk calculators for the prediction of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). Most of them were hospital-based, with limited sample sizes and insufficient external validation. These study groups collaborated to establish the REACH-B risk score, which incorporated five clinical variables to predict HCC risk. This risk score was then validated in international clinical cohorts. Evidence suggests that quantitative serum HBsAg level provides additional predictability of HCC, especially in patients with low levels of hepatitis B virus DNA. This novel marker was incorporated into a risk calculator and was internally validated. This tool will hopefully be externally validated in the near future. Risk calculators can be used to support clinical practice, and to establish preventive measures; several “off-label” extension usages have also been implemented. Albeit beneficial, several precautions and discussions should be noted in using the risk calculators. The future development of risk calculators for CHB patients can be extended by applying them to additional CHB-related outcomes, and by incorporating emerging risk parameters.     

Impact of antiviral therapy on post-hepatectomy outcome for hepatitis B-related hepatocellular carcinoma

The outcome after curative resection for hepatocellular carcinoma (HCC) remains unsatisfactory due to the high recurrence rate after surgery. In patients with hepatitis B virus (HBV)-related HCC, which is the majority of patients with HCC in Asia, a high viral load is a strong risk factor for HCC recurrence. It is logical to believe that antiviral therapy may improve the post-operative outcome by promoting viral clearance and hepatocyte regeneration, as well as improving residual liver volume in HCC patients with hepatitis B. However, the effect of antiviral therapy on clinical outcomes after liver resection in patients with HBV-related HCC remains to be established. There are two main groups of antiviral treatment for HBV-oral nucleos(t)ide analogues and interferon. Interferon treatment reduces the overall incidence of HBV-related HCC in sustained responders. However, side effects may limit its long-term clinical application. Nucleos(t)ide analogues carry fewer side effects and are potent in terms of viral suppression when compared to interferon and are typically implemented for patients with more advanced liver diseases. They may also improve the outcome after curative resection for HBV-related HCC. There are increasing evidence to suggest that antiviral therapy could suppress HBV, decrease the perioperative reactivation of viral replication, reduce liver injury, preserve the liver function before and after operation, and may lower the risk of HCC recurrence. After all, antiviral therapy may improve the survival after liver resection by reducing recurrence and delaying the liver damage by the virus, resulting in a higher chance of receiving aggressive salvage therapy during HCC recurrence.     

乙型肝炎病毒X基因突变与肝细胞癌

原发性肝细胞癌是世界上最常见的恶性肿瘤之一,慢性HBV感染是导致肝细胞癌的主要病因。HBV诱发肝细胞癌的确切机制仍不十分清楚。目前在HBV相关肝细胞癌病人血清和肝癌组织中发现了许多HBV X基因突变体,一些与肝细胞癌发生发展密切相关。本文主要就HBV X基因突变与肝细胞癌研究进展进行综述。     

Intrahepatic distribution of hepatitis B virus antigens in patients with and without hepatocellular carcinoma

AIM: To study the intrahepatic expression of hepatitis B surface antigen(HBs Ag) and hepatitis B core antigen(HBc Ag) in chronic hepatitis B patients with and without hepatocellular carcinoma. METHODS: A total of 33 chronic hepatitis B patients(mean age of 40.3 ± 2.5 years), comprising of 14 HBe Ag positive and 19 HBe Ag negative patients; and 13 patients with hepatitis B virus related hepatocellular carcinoma(mean age of 49.6 ± 4.7 years), were included in our study. Immunohistochemical staining for HBc Ag and HBs Ag was done using standard streptavidin-biotin-immunoperoxidase technique on paraffin-embedded liver biopsies. The HBc Agand HBs Ag staining distributions and patterns were described according to a modified classification system. RESULTS: Compared to the HBe Ag negative patients, the HBe Ag positive patients were younger, had higher mean HBV DNA and alanine transaminases levels. All the HBe Ag positive patients had intrahepatic HBc Ag staining; predominantly with "diffuse" distribution(79%) and "mixed cytoplasmic/nuclear " pattern(79%). In comparison, only 5% of the HBe Ag-negative patients had intrahepatic HBc Ag staining. However, the intrahepatic HBs Ag staining has wider distribution among the HBe Ag negative patients, namely; majority of the HBe Ag negative cases had "patchy" HBs Ag distribution compared to "rare" distribution among the HBe Ag positive cases. All but one patient with HCC were HBe Ag negative with either undetectable HBV DNA or very low level of viremia. Intrahepatic HBc Ag and HBs Ag were seen in 13(100%) and 10(77%) of the HCC patients respectively. Interestingly, among the 9 HCC patients on anti-viral therapy with suppressed HBV DNA, HBc Ag and HBs Ag were detected in tumor tissues but not the adjacent liver in 4(44%) and 1(11%) patient respectively. CONCLUSION: Isolated intrahepatic HBc Ag and HBs Ag can be present in tumors of patients with suppressed HBV DNA on antiviral therapy; that may predispose them to cancer development.