A meta-analysis of case-control studies on the combined effect of hepatitis B and C virus infections in causing hepatocellular carcinoma in China

Impact of the implementation of a vaccination strategy on hepatitis B virus infections in China over a 20-year period

Hepatitis B virus (HBV) vaccination has been recommended for all neonates in China since 1992. This article reviews the impact of HBV vaccination throughout the past 20 years in China. Before the introduction of the HBV vaccination program, approximately 9.8% of the general Chinese population tested positive for hepatitis B virus surface antigen (HBsAg). Since 1992, vaccination coverage has increased each year. In 1999, a National Expanded Programme on Immunization (EPI) review showed that the immunization coverage with three doses of HBV vaccine was 70.7%, and reached 99.0% in Beijing. The HBsAg carrier rate in the general population decreased to 7.2% in 2006. In particular, the prevalence of HBsAg decreased to 2.3% among children aged 5-14 years and to 1.0% among children younger than 5 years. In addition, the administration of the HBV vaccine may have reduced the risk of hepatocellular carcinoma among adults. Despite the administration of hepatitis B immunoglobulin and the HBV vaccine to children with HBsAg-positive mothers, the failure rate of HBV immunoprophylaxis was 5-10%. In China, vaccine failure was related to HBV S gene mutation and inadequate administration of HBV vaccine. The prevalence of HBV carriers in China was markedly reduced after the introduction of the universal HBV vaccination program. If we immunize all susceptible individuals with the hepatitis B vaccine (especially children), interrupt transmission, and provide antiviral treatment for existing HBV carriers, the number of new cases may be reduced to close to zero in the future and this may eventually result in the eradication of HBV.

Risk factors for hepatocellular carcinoma in a cohort infected with hepatitis B or C

BACKGROUND AND AIM

The incidence of hepatocellular carcinoma (HCC) has increased in Australia in recent decades, a large and growing proportion of which occurs among a population chronically infected with hepatitis B virus (HBV) or hepatitis C virus (HCV). However, risk factors for HCC among these high-risk groups require further characterization.

METHODS

We conducted a population-based cohort study using HBV and HCV cases notified to the New South Wales Health Department between 2000 and 2007. These were linked to cause of death data, HIV/AIDS notifications, and hospital records. Proportional hazards regression was used to identify significant risk factors for developing HCC.

RESULTS

A total of 242 and 339 HCC cases were linked to HBV (n = 43 892) and HCV (n = 83 817) notifications, respectively. For both HBV and HCV groups, being male and increasing age were significantly associated with risk of HCC. Increasing comorbidity score indicated high risk, while living outside urban areas was associated with lower risk. Hazard ratios for males were two to three times those of females. For both HBV and HCV groups, cirrhosis, alcoholic liver disease, and the interaction between the two were associated with significantly and considerably elevated risk.

CONCLUSION

This large population-based study confirms known risk factors for HCC. The association with older age highlights the potential impact of HBV and HCV screening of at-risk groups and early clinical assessment. Additional research is required to evaluate the impact of improving antiviral therapy on HCC risk.

Somatostatin analogues in advanced hepatocellular carcinoma: an updated systematic review and meta-analysis of randomized controlled trials

Background

The role of somatostatin analogues in advanced hepatocellular carcinoma (HCC) remains controversial. The aim of this study was to examine the effect of octreotide on the survival of patients with advanced HCC.

Material/Methods

Electronic databases including Medline, Embase, Cochrane controlled trials register, Web of Science and PubMed (updated to Dec 2010) and manual bibliographical searches were conducted. A meta-analysis of all randomized controlled trials (RCTs) comparing octreotide versus placebo or no treatment was performed.

Results

Eleven RCTs including 802 patients were assessed and 9 were included in the meta-analysis. Meta-analysis showed that the 6-mo and 12-mo survival rates in the octreotide group were significantly higher than those of the control group (6-mo: RR 1.41, 95%CI 1.12–1.77, P=0.003; 12-mo: RR 2.66, 95%CI 1.30–5.44, P=0.008). When including the studies using no treatment as control, with high quality, being performed in China, including >50 patients and with follow-up >2 years, the sensitivity analyses tended to confirm the primary meta-analysis. Whereas, when including the studies using placebo as control or being performed in western countries, the difference was not significant.

Conclusions

This meta-analysis demonstrates that octreotide could improve the survival of patients with advanced HCC, but possibly not in western countries. The role of detecting SSTR expression in the administration of octreotide in advanced HCC needs further investigation.

Hepatitis B virus and hepatitis C virus services offered by substance abuse treatment programs in the United States

Although substance abuse treatment programs are important contact points for providing health services for hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, availability of services in these programs has not been well characterized. This study evaluated the spectrum of HBV and HCV services offered by substance abuse treatment programs within the National Drug Abuse Treatment Clinical Trials Network. Our survey of substance abuse treatment program administrators covered availability of testing for HBV and HCV; hepatitis A virus (HAV) and HBV immunization; and HCV medical and nonmedical services. There were also questions covering clarity of guidelines for HBV and HCV testing and HAV and HBV immunization. Differences between methadone and nonmethadone programs were examined. Despite the importance of substance abuse in sustaining the hepatitis epidemics, few programs offer comprehensive HBV and HCV testing or HCV health care services. Interventions to improve access to hepatitis services for substance-abusing patients are needed.

Hepatitis B and C virus infection and hepatocellular carcinoma in China: a review of epidemiology and control measures

China has one of the highest carrier prevalences of hepatitis B virus (HBV) in the world: nearly 10% of the general population. The disease burden of HBV infection and hepatocellular carcinoma (HCC) is also believed to be among the world's largest, and that of hepatitis C virus (HCV) infection is likely to be substantial as well. However, the epidemiology and measures to control HBV and HCV infection in China remain relatively unknown outside the country. We review the epidemiology of HBV and HCV infection, the disease burden of and risk factors for HCC, and current control measures against HBV and HCV infection in China. We also discuss the relevant literature and implications for future studies of hepatitis and HCC in China.

Hepatitis B and C virus infection and hepatocellular carcinoma in China: a review of epidemiology and control measures

China has one of the highest carrier prevalences of hepatitis B virus (HBV) in the world: nearly 10% of the general population. The disease burden of HBV infection and hepatocellular carcinoma (HCC) is also believed to be among the world’s largest, and that of hepatitis C virus (HCV) infection is likely to be substantial as well. However, the epidemiology and measures to control HBV and HCV infection in China remain relatively unknown outside the country. We review the epidemiology of HBV and HCV infection, the disease burden of and risk factors for HCC, and current control measures against HBV and HCV infection in China. We also discuss the relevant literature and implications for future studies of hepatitis and HCC in China.

Lifetime risk and sex difference of hepatocellular carcinoma among patients with chronic hepatitis B and C

PURPOSE

Both hepatitis B (HBV) and C viruses (HCV) are causes of hepatocellular carcinoma (HCC), but lifetime risk and sex difference remain unclear. This study aimed to assess the lifetime risk and sex difference of HCC among patients with chronic HBV and/or HCV.

METHODS

A prospective cohort of 23,820 residents of Taiwan age 30 to 65 years were enrolled from 1991 to 1992, with 477 instances of HCC occurring subsequently. Serum samples collected at enrollment were tested for seromarkers and viral load of HBV and HCV. Newly developed HCC was ascertained through computerized data linkage with national cancer registry and death certification systems.

RESULTS

The cumulative lifetime (age 30 to 75 years) incidences of HCC for men and women positive for both HBV surface antigen (HBsAg) and antibodies against HCV (anti-HCV) were 38.35% and 27.40%; for those positive for HBsAg only, 27.38% and 7.99%; for those positive for anti-HCV only, 23.73% and 16.71%; and for those positive for neither, 1.55% and 1.03%, respectively. There was a significant male predominance in incidence of HCC for chronic HBV carriers but not for chronic carriers of HCV or both. Multivariate adjusted hazard ratio of developing HCC decreased with age in HBsAg-seropositive men but increased with age in anti-HCV-seropositive women. Among dual-infected participants, there was an inverse association between HBV and HCV viral load. Risk of HCC increased significantly with increasing viral load of HBV and HCV.

CONCLUSION

There exists a suppressive effect of HCV on HBV viral load. Individual and combined effects of the two viruses on HCC vary with sex and age.

Coinfection of hepatitis B and C viruses and risk of hepatocellular carcinoma: systematic review and meta-analysis

A subadditive effect of hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfection is possible because superinfection of one virus tends to inhibit infection of the other virus. However, studies have reported inconsistent findings, and two meta-analyses of studies from various countries (1998) and China (2005) reported a supraadditive effect for hepatocellular carcinoma (HCC) risk. Thus, we reevaluate HBV/HCV monoinfection and coinfection. Of 411 reports, we included 59 studies that assessed the association between HBV/HCV monoinfection and coinfection for HCC risk. HCC risk because of high/detectable HBV DNA and HBeAg infection was higher than HBsAg infection, whereas anti-HCV vs anti-HCV/HCV RNA was not different. Geographically, HCC risk was significantly higher in nonendemic than in HBV or HCV endemic areas. Subadditive effect for HCC risk was presented in recently published studies, cohort studies and studies conducted in HBV/HCV nonendemic areas; an additive effect was presented in studies conducted in HBV endemic areas; a supraadditive effect was presented in previously published studies, case-control studies and studies conducted in HCV endemic areas. Our results suggest HBV/HCV coinfection for HCC risk is not significantly greater than HBV/HCV monoinfection, and HCC risk due to HBV or HCV is higher in nonendemic than endemic areas. The p-heterogeneity was significant for most analyses, except HBV(+)/HCV(+) and HBV biomarker analyses. Prevention strategies targeted toward HBV or HCV monoinfected patients are needed. In addition, tailored prevention to reduce infectivity such as HBV markers (HBeAg, HBV DNA) is needed.

Intra-hepatic and extra-hepatic cholangiocarcinoma: New insight into epidemiology and risk factors

Cholangiocarcinoma (CCA) is a malignant tumour that arises from biliary epithelium at any portion of the biliary tree. CCA is currently classified as intra-hepatic or extra-hepatic CCA (EH-CCA). Recent evidences suggest that intra-hepatic CCA (IH-CCA) and EH-CCA are biologically different cancers, giving further support to a number of recent epidemiological studies showing large differences in terms of incidence, mortality and risk factors. The purpose of this manuscript is to review recent literature dealing with the descriptive epidemiology and risk factors of CCA with a special effort to compare IH- with EH-CCA.

Hepatocyte nuclear factor 4 alpha suppresses the development of hepatocellular carcinoma

Hepatocyte nuclear factor 4α (HNF4α) is a transcription factor that plays a key role in hepatocyte differentiation and the maintenance of hepatic function, but its role in hepatocarcinogenesis has yet to be examined. Here, we report evidence of a suppressor role for HNF4α in liver cancer. HNF4α expression was progressively decreased in the diethylinitrosamine-induced rat model of liver carcinogenesis. In human liver tissues, HNF4α expression was decreased in cirrhotic tissue and further decreased in hepatocarcinoma relative to healthy tissue. Notably, an inverse correlation existed with epithelial-mesenchymal transition (EMT). Enforced expression of HNF4α attenuated hepatocyte EMT during hepatocarcinogenesis, alleviated hepatic fibrosis, and blocked hepatocellular carcinoma (HCC) occurrence. In parallel, stem cell marker gene expression was inhibited along with cancer stem/progenitor cell generation. Further, enforced expression of HNF4α inhibited activation of β-catenin, which is closely associated with EMT and hepatocarcinogenesis. Taken together, our results suggest that the inhibitory effect of HNF4α on HCC development might be attributed to suppression of hepatocyte EMT and cancer stem cell generation through an inhibition of β-catenin signaling pathways. More generally, our findings broaden knowledge on the biological significance of HNF4α in HCC development, and they imply novel strategies for HCC prevention through the manipulation of differentiation-determining transcription factors in various types of carcinomas.

Hepatocellular carcinoma in individuals with HBV infection or HBV-HCV co-infection in a low endemic country

OBJECTIVE

The aim of this nationwide cohort study was to assess the risk for hepatocellular carcinoma (HCC) in patients with chronic hepatitis B virus (HBV) infection or HBV and hepatitis C virus (HCV) co-infection in Sweden, a low endemic country.

MATERIAL AND METHODS

A total of 12,080 patients with HBV and 3238 patients with HBV-HCV co-infection were notified to the Swedish institute for Infectious Disease Control between 1990 and 2004. After excluding 1850 patients with acute HBV and 584 patients infected in adult life, we analyzed the cohort of 9646 subjects with chronic HBV infection. In the co-infection cohort, 1697 patients were analyzed after excluding 1541 cases with acute HBV. The Swedish national cancer registry was used for follow-up. The HCC incidence rate in the cohorts was compared with the HCC incidence rate in the general population and the standardized incidence ratio (SIR) was calculated for different strata according to estimated infection period.

RESULTS

HCC was found in 45 patients in the HBV cohort. In the stratum of 40-49 years of infection we found a SIR of 47 and in stratum 50-59 years the SIR was 54. In the co-infected cohort 10 HCCs were found. The SIR in the stratum 20-29 years of infection was 34 and the SIR in the stratum 30 years and over was 91.

CONCLUSIONS

This national cohort study of HBV infected and HBV-HCV co-infected subjects in a low endemic country confirms a highly increased risk of liver cancer compared to the general population.

The changing pattern of epidemiology in hepatocellular carcinoma

Primary liver cancer (PLC) represents approximately 4% of all new cancer cases diagnosed worldwide. The purpose of this review is to describe some of the latest international patterns in PLC incidence and mortality, as well as to give an overview of the main etiological factors. We used two databases, GLOBOCAN 2002 and the World Health Organization (WHO) mortality database to analyze the incidence and mortality rates for PLC in several regions around the world. The highest age adjusted incidence rates (>20 per 100,000) were reported from countries in Southeast Asia and sub-Saharan Africa that are endemic for HBV infection. Countries in Southern Europe have medium-high incidence rates, while low-incidence areas (<5 per 100,000) include South and Central America, and the rest of Europe. Cirrhosis is present in about 80-90% of HCC patients and is thereby the largest single risk factor. Main risk factors include HBV, HCV, aflatoxin and possibly obesity and diabetes. Together HBV and HCV account for 80-90% of all HCC worldwide. HBV continues to be the major HCC risk factor worldwide, although its importance will most likely decrease during the coming decades due to the widespread use of the HBV vaccine in the newborns. HCV has been the dominant viral cause in HCC in North America, some Western countries and Japan. Obesity and diabetes are increasing at a fast pace throughout the world, and if they are proven to be HCC risk factors, they would account for more HCC cases in the future.

Hepatitis B virus infection among American patients with chronic hepatitis C virus infection: prevalence, racial/ethnic differences, and viral interactions

Little is known about hepatitis B virus (HBV) infection among patients with chronic hepatitis C virus (HCV) infection in the United States. We prospectively enrolled 1,257 patients with chronic HCV infection from two medical centers in New York City. A total of 61.5% (95% confidence interval, 58.8%-64.2%) had evidence of prior exposure to HBV (hepatitis B core antibody-positive), whereas 5.8% (95% confidence interval, 4.5%-7.1%) had dual infection with HBV (hepatitis B surface antigen-positive). Multivariable logistic regression analysis identified age <40 years, Asian race, injection drug use, and a greater number of lifetime sexual partners as independent risk factors for HBV-HCV dual infection. Liver biopsy results in 26 HBV-HCV-infected and 658 HCV-monoinfected patients showed that stage 3 or 4 fibrosis was significantly more common in those with HBV-HCV dual infection (84.6% versus 29.9%; P < 0.001). Patients infected with HBV and HCV had significantly lower median HCV RNA levels (1.3 versus 4.5 x 10(6) copies/mL; P < 0.001) and were less likely to have HCV RNA levels > or =5 x 10(6) copies/mL (12.3% versus 45.4%; P < 0.001) than those who had HCV monoinfection. All five patients with HBV-HCV dual infection who had undetectable HBV DNA levels had HCV RNA levels > or =5 x 10(6) copies/mL.

CONCLUSION

American patients with chronic HCV infection should be tested for HBV, especially younger patients, Asians, injection drug users, and those with an increased number of lifetime sexual partners. The presence of severe liver disease and HBV-HCV viral interactions in patients with dual infection necessitates careful but aggressive clinical management, although the optimal strategy remains to be determined.

Health disparities or data disparities: sampling issues in hepatitis B Virus infection among Asian American Pacific Islander studies

Hepatitis B virus (HBV) infection in Asian American Pacific Islanders (AAPIs) is an important health problem that must be recognized and addressed by the U.S. public health policy. However, AAPIs have been to a large degree invisible in public health data and debates and their interests have been disregarded. Moreover, an estimation of HBV infection rates reported from the National Nutritional and Health Survey Examinations III was 1.25 million; however, an estimate based on AAPI-targeted studies places the number at almost 2 million. This article discusses the perils of application of textbook methods of sampling coverage, selection, and nonresponse in studies related to AAPIs and the importance to note that some rapidly increasing racial/ethnic groups such as AAPIs have linguistic and cultural differences and these differences often cause such groups to be omitted from data collection.

Clinical evaluation of serum alpha-fetoprotein-IgM immune complexes on the diagnosis of primary hepatocellular carcinoma

We evaluated clinical significance of serum alpha-fetoprotein (AFP)-IgM immune complexes, in comparison with free AFP, on the diagnosis of primary hepatocellular carcinoma (HCC). Serum levels of AFP-IgM immune complexes and free AFP were determined by the ELISA method and electrochemiluminescence, respectively, in 103 healthy controls, 74 patients suffering from primary HCC, 27 patients suffering from liver cirrhosis, and 63 patients suffering from chronic hepatitis. The best cut-off value of AFP-IgM and free AFP for diagnosis of primary HCC were 300 AU/mL and 10 microg/L respectively, according to the area under the curve (AUC) in this study. The sensitivity of AFP-IgM and free AFP were 64.9 and 79.7%, and the specificity were 75.6 and 80.3%, respectively, when all cases of primary HCC were analyzed, and the AUC of free AFP was larger than that of AFP-IgM (0.85 vs. 0.72, Z=3.21). However, in case of primary HCC at early stages (stages I and II) were analyzed, the AUC of AFP-IgM was larger than that of free AFP (0.91 vs. 0.82, Z=1.73), which demonstrated that the sensitivity of AFP-IgM and free AFP were 94.4 and 72.2%, and the specificity were 81.9 and 79.9%, respectively. When both AFP-IgM and free AFP were positive, the specificity of diagnosis of primary HCC was 89.1%, and the efficacy was 79.0%. It is concluded that either sensitivity or specificity of serum level of AFP-IgM immune complexes was higher than that of free AFP in the diagnosis of primary HCC at early stages. As there was false positive AFP-IgM existed in the patients suffering from cirrhosis and chronic hepatitis, the combination of free AFP and AFP-IgM could significantly increase specificity and decrease false negative and/or false positive in the primary HCC at early stages.

Proteomic identification of molecular targets of gambogic acid: role of stathmin in hepatocellular carcinoma

Gamboge has been developed as an injectable drug for cancer treatment in China. In this study, the inhibition ratio and their IC(50) values of two derivatives from Gamboge in hepatocellular carcinoma (HCC) were determined. Proteomic approach was employed to reveal the target proteins of these two derivatives, gambogic acid (GA), and gambogenic acid (GEA). HCC cells were cultured under varied conditions with the addition of either GA or GEA. Twenty differentially expressed proteins were identified and the four most distinctly expressed proteins were further validated by Western blotting. GA and GEA revealed inhibitory effects on HCC cell proliferation. The expression of cyclin-dependent kinase 4 inhibitor A and guanine nucleotide-binding protein beta subunit 1 were upregulated by both xanthones, whilst the expression of 14-3-3 protein sigma and stathmin 1 (STMN1) were downregulated. Furthermore, overexpression of STMN1 in HCC cells decreased their sensitivity, whilst small interfering RNAs targeting STMN1 enhanced their sensitivity to GA and GEA. In conclusion, our study suggested for the first time that STMN1 might be a major target for GA and GEA in combating HCC. Further investigation may lead to a new generation of anticancer drugs exerting synergistic effect with conventional therapy, thus to promote treatment efficacy.

Hepatitis B-related hepatocellular carcinoma: epidemiological characteristics and disease burden

Worldwide, 350 million people are chronically infected with hepatitis B virus (HBV) who are at greater risk of hepatocellular carcinoma (HCC) compared with uninfected people. The relative risks of HCC among people infected with HBV ranges from 5 to 49 in case-control studies and from 7 to 98 in cohort studies. More than 50% of HCC cases worldwide and 70-80% of HCC cases in highly HBV endemic regions are attributable to HBV. Incidence of HCC (per 100,000 person/year) among people with chronic HBV infection ranges from 400 to 800 in male and from 120 to 180 in female. Factors associated with increased risk of HCC include demographic characteristics (male sex and older age), lifestyles (heavy alcohol consumption and smoking), viral factors (genotype C, D F, high level of HBV DNA, core/precore mutation) and clinical factors (cirrhosis, elevated alpha-fetoprotein (AFP) and alanine aminotransferase (ALT)). HBV-related HCC has extremely poor prognosis with median survival less than 16 months. Survival rates of HBV-related HCC ranged from 36% to 67% after 1 year and from 15% to 26% after 5 year of diagnosis. Older age, liver function impairment, vascular invasion, tumour aggressiveness and elevated AFP are associated with HCC survival. Global burden of HBV-related liver disease is still a major challenge for public health in the 21st century. While decreases in incidence of HBV infection have been observed in birth cohorts following the introduction of universal infant HBV vaccination programme, HBV-related HCC incidence in is projected to increase for at least two decades because of the high prevalence of chronic HBV infection and prolonged latency to HCC development. To reduce HBV-related HCC continued expansion of universal infant HBV vaccination is required along with antiviral therapy targeted to those individuals at highest risk of HCC. Broad public health strategies should include routine testing to identify chronic HBV infection, improved health infrastructures including human resource to provide diagnosis and treatment assessment.

Molecular pathogenesis and early detection of hepatocellular carcinoma--perspectives from West Africa

This article reviews mechanisms involved in development of hepatocellular carcinoma and how host and environmental factors interact at a molecular level to cause cancer. These processes are intimately linked with strategies for early detection since molecular intermediates on the carcinogenesis pathway can now be detected with increasing levels of sensitivity. Similarly host factors influencing response to environmental agents, together with substances produced by early cancers, can be assayed in fine detail with new and emerging technologies. These advances in the field of biomarkers may lead to more rapid diagnosis and ultimately to improved survival as novel therapeutic strategies are adopted.

Hepatitis B virus DNA in patients with hepatitis B-related liver cirrhosis with or without hepatocellular carcinomas: a matched case-control study

OBJECTIVE

The relationship between serum viremia and the development of hepatocellular carcinoma (HCC) in patients with hepatitis B virus (HBV)-related cirrhosis remains unclear. We aimed at calculating odds ratios (OR) for the presence of HCC over a range of HBV DNA levels in these patients.

METHODS

Patients were identified retrospectively and 155 pairs of matched, treatment-naive HBV-related cirrhotic patients with and without HCC were recruited. Their serum HBV DNA levels were measured at HCC diagnosis, or at the equivalent age in non-HCC patients, and correlations between the presence of HCC and different DNA levels were calculated using conditional logistic regression.

RESULTS

The median HBV DNA level was significantly higher in HCC patients than in non-HCC patients (5.15 vs 4.83 log(10) copies/mL, P = 0.024). The overall OR for HCC in patients with HBV DNA > or = 3 log(10) copies/mL was 2.13, compared with patients with levels <3 log(10) copies/mL. Compared with patients with <3 log(10) copies/mL, the OR for HCC were 2.39 and 2.61 for patients with 4 to <5 and 5 to <6 log(10) copies/mL, respectively, while the OR for DNA levels of > or = 6 log(10) copies/mL were not significantly different.

CONCLUSION

In HBV-related cirrhosis, a detectable serum HBV DNA was associated with the presence of HCC, but the likelihood of having HCC did not successively increase with increasing serum HBV DNA levels: patients with serum HBV DNA levels between 4 and <6 log(10) copies/mL were most likely to present with HCC.

Epidemiology and prevention of hepatocellular carcinoma

A meta-analysis on the seroprevalence of hepatitis B surface antigen (HBsAg) and antibodies against hepatitis C virus (anti-HCV) in 27881 hepatocellular carcinomas from 90 studies confirmed wide international variations. A predominance of HBsAg was found in hepatocellular carcinomas from most Asian, African and Latin American countries, but anti-HCV predominated in Europe, North America, Japan, Pakistan, Mongolia, and Egypt. Anti-HCV was found more often than HBsAg in Europe and the United States. Twenty-five years after having been licensed, HBV vaccination programmes are now carried out in 158 countries, but they have yet to reach many high-risk populations in sub-Saharan Africa and Asia. In the absence of a vaccine, the prevention of HCV infection requires an integrated strategy (i.e., screening of blood donations, safe injection practices, and avoidance of unnecessary injections).

Natural history: the importance of viral load, liver damage and HCC

Chronic hepatitis B and hepatitis C virus infections are the major causes of liver disease, hepatocellular carcinoma (HCC) and liver-related mortality worldwide. Among factors known to influence the natural history of viral hepatitis are age at the time of infection, duration of infection, serum alanine aminotransferase (ALT) levels, male sex, alcohol consumption, and coinfections. In hepatitis B, serum HBV DNA concentration emerges as the key factor for predicting the development of liver disease. Even patients with low viraemia seem at increased risk for liver cirrhosis and HCC. Coinfections with hepatitis C, hepatitis D and/or HIV are common and are associated with a more severe liver disease. The course of chronic hepatitis C is variable, but usually fibrosis advances slowly. In addition to the better-known factors- including coinfections with HBV and HIV- progression of liver disease is adversely affected by smoking, hepatic steatosis and insulin resistance.

Biological impact of hepatitis B virus X-hepatitis C virus core fusion gene on human hepatocytes

AIM: To investigate the biological impact of hepatitis B virus X- hepatitis C virus core (HBV X-HCV C) fusion gene on hepatoma cells.

METHODS: The recombinant adenoviruses Ad-XC, Ad-X and Ad-C expressing HBV X-HCV C fusion gene, HBV X gene and HCV C gene were constructed, respectively. Hepatoma cells were infected with different recombinant adenoviruses. MTT, colony-forming experiment, FCM, TUNEL assay were performed to observe the biological impact of the HBV X-HCV C fusion gene on liver cells.

RESULTS: MTT showed that the Ad-XC group cells grew faster than the other group cells. Colony-forming experiment showed that the colony-forming rate for the Ad-XC group cells was significantly higher than that for the other group cells. FCM analysis showed that Ad-XC/Ad-X/Ad-C infection enhanced the progression of G1→S phase in the HepG2 cell cycle. The apoptosis index of the Ad-XC, Ad-X, Ad-C group cells was significantly lower than that of the Ad0 and control group cells. Semi-quantitative RT-PCR showed that the expression level of c-myc was the highest in Ad-XC infected cells. Tumor formation was found at the injected site of mice inoculated with Ad-XC-infected LO2 cells, but not in control mice.

CONCLUSION: Ad-XC, Ad-X and Ad-C facilitate the proliferation activity of HepG2 cells and inhibit their apoptosis in vitro. The effect of Ad-XC is significantly stronger than that of Ad-X and Ad-C. Up-regulation of c-myc may be one of the mechanisms underlying the synergism of HBV X and HCV C genes on hepatocarcinogenesis in athymic nude mice.

Two-dimensional differential gel electrophoresis/analysis of diethylnitrosamine induced rat hepatocellular carcinoma

Diethylnitrosamine (DEN) is a known carcinogen that can alkylate DNA molecules. In rats, DEN-induced hepatocellular carcinoma (HCC) model is well established. In this study, we used a two-dimensional differential gel electrophoresis (2D-DIGE) system and liquid chromatography/mass spectrometry/mass spectrometry to identify the differential expression protein profiles between the DEN-induced HCC and healthy liver cells. Western blotting and semiquantitative RT-PCR were used to further confirm the results. Seventeen differentially expressed spots were identified in DEN-induced HCC cells. Among all, the most prominent upregulated proteins include the members of the glutathione S-transferase super family, aldo-keto reductase superfamily and proteins involved in the response to oxidative stress. Downregulation was observed in 2 proteins that were known to contribute to hepatic dysfunction. This study provides the first comprehensive protein profiling of the DEN-induced HCC in rats. This model simulates the differential protein expression of human HCC and may be useful for further understanding the mechanism of HCC tumorigenesis.

Acute hepatitis B in patients with or without underlying chronic HCV infection

BACKGROUND AND AIM

Acute hepatitis B course may be significantly modified by underlying chronic hepatitis C. The aim of this study was to compare clinical and virological characteristics of acute hepatitis B in patients with or without chronic hepatitis C virus (HCV) infection.

MATERIALS AND METHODS

Twenty-seven patients with symptomatic acute hepatitis B were enrolled: 14 with underlying chronic HCV (Group A) and 13, matched by age and gender, with single hepatitis B (Group B). All patients were followed-up until HBsAg negativization.

RESULTS

Group A patients were HCV-RNA-negative on hospital admission and all but one remained negative during follow-up. HBeAg tested positive in 92.9% and 84.6% of Groups A and B patients, respectively. ALT, bilirubin, prothrombin time values and HBsAg titer were similar in both groups. Nevertheless, lower mean HBV-DNA levels (p=0.03), a shorter duration of HBsAg positivity (p<0.01) and of symptoms before ALT peak (p=0.014), and significantly lower peak ALT values (p=0.03) were observed in Group A compared to Group B patients.

CONCLUSIONS

Acute HBV infection suppressed HCV replication. Conversely, the underlying HCV infection exerted a modulatory effect on HBV replication which influenced the course, though not the outcome, of the acute disease. Although acute hepatitis B showed a mild clinical course in both groups of patients, HBV vaccination should be suggested to risk subjects.

Hepatitis B virus DNA in liver tissue and risk for hepatocarcinogenesis in patients with hepatitis C virus-related chronic liver disease. A prospective study

AIMS

To prospectively study whether occult hepatitis B virus (HBV) infection can promote the development of hepatocellular carcinoma (HCC) in patients with hepatitis C virus (HCV)-related chronic liver disease. In addition, to evaluate the difference among HBV DNA-negative patients and patients with high and low HBV copy numbers.

METHODS

A total of 167 patients with HCV-related chronic liver disease without HBV surface antigen (HBsAg) were studied. HBV DNA in liver tissue was determined using polymerase chain reaction (PCR).

RESULTS

HBV DNA was detected in 9 of 167 patients (5.4%) by single PCR and in 25 patients (15.0%) by nested PCR. HCC developed in 12 of 167 patients (7.2%). Ten of 142 HBV DNA-negative patients (7.0%) and 2 of 9 patients with a high HBV copy number (22.2%) developed HCC, whereas none of 16 patients with a low HBV copy number developed HCC. The incidence rate of HCC in patients with a high HBV copy number was significantly higher than in HBV DNA-negative patients and patients with low HBV copy number.

CONCLUSION

A high amount of HBV DNA in liver tissue of HBsAg-negative patients with HCV-related liver disease might be associated with HCC development.

Natural history of chronic hepatitis B: special emphasis on disease progression and prognostic factors

The natural history of chronic hepatitis B virus (HBV) infection and disease is complex and highly variable. We review the natural history of chronic hepatitis B with emphasis on the rates of disease progression and factors influencing the course of the liver disease. Chronic hepatitis B is characterized by an early replicative phase (HBeAg positive chronic hepatitis) and a late low or non-replication phase with HBeAg seroconversion and liver disease remission (inactive carrier state). Most patients become inactive carriers after spontaneous HBeAg seroconversion with good prognosis, but progression to HBeAg negative chronic hepatitis due to HBV variants not expressing HBeAg occurs at a rate of 1-3 per 100 person years following HBeAg seroconversion. The incidence of cirrhosis appears to be about 2-fold higher in HBeAg negative compared to HBeAg positive chronic hepatitis. In the cirrhotic patient the 5-year cumulative risk of developing hepatocellular carcinoma is 17% in East Asia and 10% in the Western Europe and the United States and the 5-year liver related death rate is 15% in Europe and 14% in East Asia. There is a growing understanding of viral, host and environmental factors influencing disease progression, which ultimately could improve the management of chronic hepatitis B.

Proteomic analysis of EZH2 downstream target proteins in hepatocellular carcinoma

Enhancer of zeste homolog 2 (EZH2) is suggested to be a potential therapeutic target and a diagnostic marker for cancer. Our previous study also showed the critical role of EZH2 in hepatocellular carcinoma (HCC) tumorigenesis. The present study is aimed at revealing the comprehensive downstream pathways of EZH2 by functional proteomic profiling. Lentivirus mediated RNA interference (RNAi) was employed to knockdown EZH2 in HCC cells. The 2-DE was employed to compare the expression profile difference between parental and EZH2-knockdown HCC cells. In total, 28 spots were differentially expressed during EZH2 inhibition. Among all, 18 proteins were identified by PMF with MALDI-TOF MS. Western blotting further validated upregulation of 60S acidic ribosomal protein P0 (L10E), and downregulation of two proteins with EZH2 inhibition: stathmin1 and probable protein disulfide isomerase (PDI) ER-60 precursor (ERp57). Moreover, L10E was downregulated with overexpression of EZH2 in hepatocytes, and L10E reversed the effect of EZH2 on cell proliferation, suggesting it a downstream target of EZH2. The comprehensive and comparative analyses of proteins associated with EZH2 could further our understanding on the downstream signal cascade of EZH2 leading to tumorigenesis.

Understanding the pathogenesis and management of hepatitis B/HIV and hepatitis B/hepatitis C virus coinfection

The approach to the hepatitis B virus (HBV)-infected patient who is also infected with HIV or hepatitis C virus (HCV) is very different from the approach to the patient with only one virus infection. HBV/HIV coinfection is common. Agents that have dual activity against HBV and HIV should be considered as treatment of choice in combination regimens in HBV/HIV-coinfected patients beginning antiretroviral therapy. In HBV/HCV coinfection HCV usually tends to predominate over HBV. More investigation is needed into the mechanisms by which viral pathogenesis is altered and the optimal treatment modalities for coinfected patients.

Lipids changes in liver cancer

Liver is one of the most important organs in energy metabolism. Most plasma apolipoproteins and endogenous lipids and lipoproteins are synthesized in the liver. It depends on the integrity of liver cellular function, which ensures homeostasis of lipid and lipoprotein metabolism. When liver cancer occurs, these processes are impaired and the plasma lipid and lipoprotein patterns may be changed. Liver cancer is the fifth common malignant tumor worldwide, and is closely related to the infections of hepatitis B virus (HBV) and hepatitis C virus (HCV). HBV and HCV infections are quite common in China and other Southeast Asian countries. In addition, liver cancer is often followed by a procession of chronic hepatitis or cirrhosis, so that hepatic function is damaged obviously on these bases, which may significantly influence lipid and lipoprotein metabolism in vivo. In this review we summarize the clinical significance of lipid and lipoprotein metabolism under liver cancer.

NS5A protein of HCV enhances HBV replication and resistance to interferon response

HCV and HBV are the major causes of chronic liver diseases worldwide. Patients with both viruse's co-infection tend to develop severer liver diseases and are at high risk of liver-related death. NS5A protein of HCV plays key roles in HCV replication and inhibition of host immune responses. In this study, we described the establishment of HepG2-derived cell line that stably expresses NS5A protein and the application of a cellular system for HBV replication based on a recombinant adenovirus carrying HBV genome. Our results demonstrated that NS5A enhances the expression of S and E proteins of HBV, as well as the synthesis of viral DNA. Moreover, we showed that NS5A assists HBV to escape interferon responses. These data suggested that NS5A of HCV may employ multiple strategies contributing to the enhancement of HBV replication and interferon resistance during the co-infection of HCV and HBV.

Future directions for research on Silybum marianum for cancer patients

Silymarin (Silybum marianum [L.] Gaertn. [Asteraceae]) is a promising agent for cancer prevention, adjuvant cancer treatment, and reduction of iatrogenic toxicity. Although it is safe and free of serious adverse side effects, few studies have evaluated its use alongside conventional cytotoxic therapies, and adverse events associated with long-term administration are uncertain. Although it may prevent some types of cancer, its promotion of tissue regeneration and its potential estrogen activity could promote the growth of some tumors. Further clinical trials using authenticated fractions of silymarin as simple and complex derivatives are required prior to any general recommendations. Future research should focus on authentication of active chemicals, pharmacokinetics, adverse interactions and quality control, prevention of cancer initiation and progression, adjuvant therapy for specific cancers, and prevention of toxicity from anticancer therapies.

Viral interaction and clinical implications of coinfection of hepatitis C virus with other hepatitis viruses

Coinfection with other hepatitis viruses modifies the viral profile in serum and leads to more liver damage and more rapid progression during the course of hepatitis C virus infection. The viral interference is not only carried out by virus-virus or by virus-cell interactions but also by an enhanced immune response. A superinfecting viral infection does not crossactivate protective immune responses to the pre-existing virus albeit the latter can become undetectable. The induced cytokine stimulation might enhance the hepatic inflammation. Moreover, hepatitis B virus coinfection increases the risk of development of hepatocellular carcinoma in hepatitis C virus patients through common necro-inflammatory pathways or by direct oncogenic activity of hepatitis B virus. Viral interaction also complicates the management of the coinfection because hepatitis C virus impairs the humoral response to hepatitis A virus and hepatitis B virus vaccines, and because pharmacological suppression of hepatitis C virus endangers dually infected patients with reactivation of coinfected hepatitis B virus. Optimized strategies and follow-up are thus necessary in the treatment of infection with multiple viruses. It seems thus necessary to look for markers of hepatitis B virus and/or hepatitis D virus infection in chronic hepatitis patients positive for hepatitis C virus antibodies but negative for hepatitis C virus RNA, and equally well to search for hepatitis C virus RNA in HBsAg-negative/anti-HBc-positive patients with a low level of serum hepatitis B virus DNA.

The contributions of hepatitis B virus and hepatitis C virus infections to cirrhosis and primary liver cancer worldwide

BACKGROUND/AIMS

End-stage liver disease accounts for one in forty deaths worldwide. Chronic infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) are well-recognized risk factors for cirrhosis and liver cancer, but estimates of their contributions to worldwide disease burden have been lacking.

METHODS

The prevalence of serologic markers of HBV and HCV infections among patients diagnosed with cirrhosis or hepatocellular carcinoma (HCC) was obtained from representative samples of published reports. Attributable fractions of cirrhosis and HCC due to these infections were estimated for 11 WHO-based regions.

RESULTS

Globally, 57% of cirrhosis was attributable to either HBV (30%) or HCV (27%) and 78% of HCC was attributable to HBV (53%) or HCV (25%). Regionally, these infections usually accounted for >50% of HCC and cirrhosis. Applied to 2002 worldwide mortality estimates, these fractions represent 929,000 deaths due to chronic HBV and HCV infections, including 446,000 cirrhosis deaths (HBV: n=235,000; HCV: n=211,000) and 483,000 liver cancer deaths (HBV: n=328,000; HCV: n=155,000).

CONCLUSIONS

HBV and HCV infections account for the majority of cirrhosis and primary liver cancer throughout most of the world, highlighting the need for programs to prevent new infections and provide medical management and treatment for those already infected.

Causes of death after diagnosis of hepatitis B or hepatitis C infection: a large community-based linkage study

BACKGROUND

Hepatitis B and hepatitis C virus infections are common causes of death related to liver disease. In this large study, we aimed to investigate all cause mortality of the viruses in a community-based setting.

METHODS

In the study population, 39,109 people had hepatitis B, 75,834 had hepatitis C, and 2604 had hepatitis B and hepatitis C co-infection, notified to the New South Wales state health department, Australia, between 1990 and 2002. Their data were probabilistically linked to the National Death Index. Standardised mortality ratios for all causes of death were calculated and adjusted for age, sex, and calendar year.

RESULTS

The number of deaths identified by the linkage were 1233 (3.2%) for hepatitis B, 4008 (5.3)% for hepatitis C, and 186 (7.1)% for hepatitis B and C co-infection. Raised risk of liver-related death (standardised mortality ratios 12.2, 95% CI 10.7-13.9; 16.8, 15.4-18.3, and 32.9, 23.1-46.7, for hepatitis B, hepatitis C, and hepatitis B and C co-infected patients, respectively) and drug-induced death (1.4, 1.0-2.0; 19.3, 18.1-20.5; and 24.7, 18.2-33.5, respectively) were detected. In people with hepatitis C, raised risk of dying from drug-related causes was significantly greater than from liver-related causes (p=0.012), with the greatest excess risk in women aged 15-24 years (56.9, 39.2-79.9).

INTERPRETATION

All groups had increased risk of liver-related death compared with the standard population, with the greatest excess in people diagnosed with hepatitis B and hepatitis C co-infection. Our data highlight that young people with hepatitis C and with co-infection face a higher mortality risk from continued drug use than from their infection, whereas the main cause of hepatitis B death was liver related.

Southern Europe as an example of interaction between various environmental factors: a systematic review of the epidemiologic evidence

Hepatitis B virus (HBV), hepatitis C virus (HCV) and alcohol consumption are major causes of hepatocellular carcinoma (HCC) worldwide. We performed a systematic review of epidemiologic studies carried out on HCC aetiology in Southern Europe, an area with an intermediate-high prevalence of these agents as well as of putative risk factors such as tobacco smoking, diabetes and obesity. To retrieve the articles, we performed a Medline search for titles and abstracts of articles. After the Medline search, we reviewed the papers and reference lists to identify additional articles. A synergism between HCV infection and HBV infection, overt (hepatitis B virus antigen (HbsAg) positivity) or occult (HBsAg negativity with presence of HBV DNA in liver or serum), is suggested by the results of some studies. The pattern of the risk for HCC due to alcohol intake shows a continuous dose-effect curve without a definite threshold, although most studies found that HCC risk increased only for alcohol consumption above 40-60 g of ethanol per day. Some evidence supports a positive interaction of alcohol intake probably with HCV infection and possibly with HBV infection. A few studies found that coffee has a protective effect on HCC risk due to various risk factors. Some data also support a role of tobacco smoking, diabetes and obesity as single agents or preferably co-factors in causing HCC. In countries with a relatively high alcohol consumption and intermediate levels of HCV and HBV infections (1-3% of population infected by each virus), such as Mediterranean countries, the three main risk factors together account for about 85% of the total HCC cases, leaving little space to other known risk factors, such as haemochromatosis, and to new, still unrecognised, factors as independent causes of HCC.

Cancer incidence in people with hepatitis B or C infection: a large community-based linkage study

BACKGROUND/AIMS

Risks of hepatocellular carcinoma (HCC) following hepatitis B and/or hepatitis C virus (HBV/HCV) infection are well known, those for other cancers are less well understood. The aim was to quantify the risk of cancers among persons diagnosed with HBV/HCV infections.

METHODS

The data from a cohort of 39109 HBV, 75834 HCV, and 2604 HBV/HCV co-infected persons notified to the State health department, 1990-2002, were probabilistically linked to the Cancer Registry and standardised incidence ratios (SIRs) for cancer were calculated.

RESULTS

The match rate for any cancer was 2.7%, 2.3% and 3.3% for HBV, HCV and HBV/HCV co-infected notifications. SIRs for HCC were 30.6 (95% CI 25.7-36.5), 22.7 (95% CI 19.1-26.5) and 30.3 (95% CI 13.6-67.5), respectively. Increased risk was detected for Burkitt's lymphoma and HBV (SIR 12.9, 95% CI 5.4-30.9) and immunoproliferative malignancies following HCV (SIR 5.6, 95% CI 1.8-17.5).

CONCLUSIONS

The risk of HCC in the infected cohort was 20-30 times greater than in the uninfected population with SIRs two to three times greater than those for the other HBV/HCV infection associated cancers. The modest though significant risk of immunoproliferative malignancies associated with HCV infection is consistent with recent findings.

HIV-related liver disease: infections versus drugs

HIV-infected individuals have myriad causes of hepatotoxicity that range from mild hepatitis to significant liver failure with its associated morbidity and mortality, especially in the setting of chronic viral hepatitis (HCV and HBV). Immune restoration by HAART therapy can contribute liver-related toxicity in HIV-coinfected patients. Clinicians need to be aware of this problem and individualize management in this challenging clinical scenario. Avoidance of potentially hepatotoxic agents or close monitoring during treatment of HIV may prevent liver failure in patients who have HIV. Furthermore, vaccination against hepatitis A virus and HBV in nonimmune HIV individuals may prevent acquisition of hepatitis A virus and HBV infections in patients who have HIV. Finally, treatment of HIV, and, if appropriate, treatment of those who are coinfected with HCV and HBV with close monitoring, may improve the outcome of patients who have HIV and are at risk fo r significant hepatotoxicity during treatment from immune restoration or hypersensitivity reactions.

Hepatitis Viruses, Alcohol, and Tobacco in the Etiology of Hepatocellular Carcinoma in Italy

Mortality rates of hepatocellular carcinoma (HCC) are high in Italy compared with other Western countries. To elucidate further the role of hepatitis B virus (HBV), hepatitis C virus (HCV), alcohol drinking, and tobacco smoking in the etiology of HCC, we carried out a hospital-based case-control study in two areas of Italy: the province of Pordenone in the Northeast and the town of Naples in the South. A total of 229 HCC cases (median age, 66 years) and 431 controls (median age, 65 years) answered a questionnaire and provided blood samples between 1999 and 2002. Odds ratios (OR), percent attributable risks, and corresponding 95% confidence intervals were computed using unconditional multiple logistic regression. ORs for hepatitis B surface antigen (HBsAg) positive versus HBsAg negative and for anti-HCV antibody positive versus anti-HCV antibody negative were 20.2 and 15.6, respectively. Positivity for both markers was associated with an OR of 51.6. Sensitive molecular techniques applied to sera in a subset of HCC cases disclosed a very small number of occult hepatites. Maximal lifetime alcohol intake of > or =35 versus <7 drinks/wk was associated with an HBV/HCV adjusted OR of 5.9. Tobacco smoking was unrelated to HCC risk overall but seemed to enhance HCC risk among virus carriers. Overall, 61% of HCC were attributable to HCV, 13% to HBV, and 18% to heavy alcohol drinking. In conclusion, our study confirms the importance of HCV in HCC etiology in Italy where the widespread dissemination of the virus dates back four or five decades.

Influence of liver cancer on lipid and lipoprotein metabolism

Liver plays a key role in the metabolism of plasma apolipoproteins, endogenous lipids and lipoproteins. Hepatocellular carcinoma (HCC) is one of the most common fatal malignant tumors in China and in other Southeast Asian countries. This has been attributed to the high incidence of hepatitis B infection. Hepatitis B proteins, such as the hepatitis B X protein (HBx) that is large hepatitis B surface protein could regulate transcription of many candidate genes for liver carcinogenesis. It has known that patients who suffered from acute hepatitis B could have lipid disorders such as decreased plasma level of high-density lipoproteins (HDL). Furthermore, aberrations of lipid metabolism are often seen in the chronic hepatitis B infection. Plasma lipid profiles could be changed under HCC. In majority of the reports in HCC, plasma levels of triglycerides (TG), cholesterol, free fatty acids (FFA), HDL, low-density lipoproteins (LDL), lipoprotein (a) (Lp(a)), apolipoprotein AI (apoAI) and apoB were slight to significantly decreased, however, in some cases plasma levels of TG and Lp(a) might be increased. It has been suggested that analysis of plasma levels of lipids, lipoproteins and apolipoproteins in the patients suffered from HCC reflects on the hepatic cellular impairment status. Studies revealed that alterations seen in the plasma levels of lipids, lipoproteins and apolipoproteins reflecting patients' pathologic conditions. Decreased serum levels of cholesterol and apoAI may indicate a poor prognosis. Human leukaemic cells and certain tumor tissues have a higher receptor-mediated uptake of HDL and LDL than the corresponding normal cells or tissues. LDL and HDL have therefore been proposed as a carrier for the water-insoluble anti-cancer agents.

The global health burden of infection-associated cancers in the year 2002

Several infectious agents are considered to be causes of cancer in humans. The fraction of the different types of cancer, and of all cancers worldwide and in different regions, has been estimated using several methods; primarily by reviewing the evidence for the strength of the association (relative risk) and the prevalence of infection in different world areas. The estimated total of infection-attributable cancer in the year 2002 is 1.9 million cases, or 17.8% of the global cancer burden. The principal agents are the bacterium Helicobacter pylori (5.5% of all cancer), the human papilloma viruses (5.2%), the hepatitis B and C viruses (4.9%), Epstein-Barr virus (1%), human immunodeficiency virus (HIV) together with the human herpes virus 8 (0.9%). Relatively less important causes of cancer are the schistosomes (0.1%), human T-cell lymphotropic virus type I (0.03%) and the liver flukes (0.02%). There would be 26.3% fewer cancers in developing countries (1.5 million cases per year) and 7.7% in developed countries (390,000 cases) if these infectious diseases were prevented. The attributable fraction at the specific sites varies from 100% of cervix cancers attributable to the papilloma viruses to a tiny proportion (0.4%) of liver cancers (worldwide) caused by liver flukes.