Hepatitis viruses (other than hepatitis B and C viruses) as causes of hepatocellular carcinoma: an update

Chronic hepatitis B and C virus infections are universally accepted as causes of hepatocellular carcinoma in humans. Hepatitis A and E viruses cause only acute self‐limiting infections of the liver. Of the remaining hepatitis viruses ‐ Delta hepatitis, hepatitis G (GB‐C), TT and SEN ‐ all have at some time been incriminated as causes of hepatocellular carcinoma. Delta hepatitis virus requires helper functions from hepatitis B virus to become invasive. Chronic Delta/hepatitis B viral co‐infection runs a more severe course than that resulting from chronic hepatitis B virus infection alone, with progression to cirrhosis being more likely and more rapid. A substantial majority of the early studies did not find an increased incidence of hepatocellular carcinoma in co‐infected individuals. But more recently, an increased incidence of the tumour has been recorded more often than no increase. Further studies are needed to draw a firm conclusion with regard to the hepatocarcinogenic effect of dual Delta/hepatitis B virus co‐infection. With one exception, no published study (of 13) has incriminated chronic infection with hepatitis G virus as a cause of hepatocellular carcinoma. The dissenting study, published in 1999, was the only one performed in the United States. Fewer studies of the hepatocarcinogenic effect of TT virus have been performed. Apart from one study, published in 1999, no convincing evidence is available that supports a causal role for TT virus in hepatocarcinogenesis. The exception was in Japanese patients with high hepatitis C viral loads but independent of chronic hepatitis C virus infection. No evidence has been produced to indicate that SEN virus causes hepatocellular carcinoma.     

Hepatitis B e antigen-negative chronic hepatitis B in Hong Kong

Hepatitis B e antigen-negative chronic hepatitis B (e-CHB) has been reported in Asia but its prevalence and clinical significance have not been determined. The aims of this study were to determine the prevalence of e-CHB in Hong Kong and the frequency of precore and core promoter mutations in these patients. A cross-sectional study was performed in 350 consecutive Chinese patients (230 men and 120 women; mean age +/-SD, 42 +/- 13 years) with chronic hepatitis B virus infection. A total of 243 (69%) patients were hepatitis B e antigen (HBeAg)-negative of whom 15% had clinical cirrhosis. In the remaining 85% of patients, 63% had normal and 22% had elevated transaminases. Serum hepatitis B virus (HBV) DNA was detectable using branched DNA assay in 46% of HBeAg-negative patients with clinical cirrhosis/elevated transaminases. Forty-five percent of the patients with e-CHB had the precore stop codon mutation, and an additional 41% had core promoter changes. There was no correlation between the presence of precore/core promoter mutations and liver disease or HBV-DNA levels. Overall, 17% of HBeAg-negative patients were viremic and had evidence of chronic liver disease (e-CHB) with mean HBV-DNA levels comparable with that in HBeAg-positive patients. In summary, we found that e-CHB may be present in up to 17% of HBeAg-negative patients seen in a tertiary referral center in Hong Kong. e-CHB may be a heterogeneous condition and is not invariably associated with the precore HBV mutant. Population studies are needed to determine the true prevalence of e-CHB in Asia and to assess its natural course and response to treatment.     

乙型和丙型肝炎病毒感染与肝细胞癌

为探讨乙型和丙型肝炎病毒（ＨＢＶ和ＨＣＶ）感染与肝细胞癌（肝癌）发生的关系，采用ＥＬＩＳＡ和聚合酶链反应（ＰＣＲ）对沈阳地区１１７例肝癌、１０７例肝硬化和４５例血液透析患者血清进行了ＨＢＶ和ＨＣＶ血清标志及ＨＢＶＤＮＡ和ＨＣＶＲＮＡ检测，并采用限制性片段长度多态性对其中７３例ＨＣＶＲＮＡ阳性血清进行了ＨＣＶ基因分型。结果，肝癌组ＨＢＶ感染率（６０７％）显著高于ＨＣＶ感染率（３３３％，Ｐ＜００１），肝硬化组ＨＢＶ感染率（４３９％）明显高于ＨＣＶ感染率（２９０％，Ｐ＜００５）；血液透析组ＨＢＶ和ＨＣＶ重叠感染率（２６７％）明显高于肝硬化组（１０３％，Ｐ＜００５）；各组均以ＨＣＶⅡ型为主（６５２％～８００％），ＨＣＶⅢ型次之（２００％～３１４％）。结果提示：沈阳地区肝癌的诱发因素仍以ＨＢＶ为主，血液透析患者ＨＢＶ和ＨＣＶ重叠感染的机会更大，ＨＣＶⅡ型感染在本地区ＨＣＶ相关性肝癌和肝硬化的发生中可能起主要作用。     

Hepatitis B virus integration in hepatitis B virus-related hepatocellular carcinoma in childhood.

In Taiwan, hepatocellular carcinoma is one of the major malignancies in children between 5 and 14 yr of age. We studied the status of hepatitis B virus DNA in the hepatocellular carcinoma and nontumorous liver tissues of eight children with positive serum HBsAg and maternal HBsAg. The hepatocellular carcinoma tissues from five of the eight children showed integration of hepatitis B virus DNA into host cellular DNA sequences. A pattern of single-site integration in four children and a multiple-site integration pattern in one child were demonstrated. In the remaining three children, hepatitis B virus DNA could not be demonstrated in the tumor tissues. Using subgenomic fragments of the hepatitis B virus genome as probes, we found that the X gene fragment and the surface antigen gene fragment were the most conserved sequences. The single-site integration of hepatitis B virus DNA in childhood hepatocellular carcinoma may have hit the critical region, resulting in insertional mutagenesis and early development of hepatocellular carcinoma. With a short incubation period and less exposure to environmental carcinogens during early life, childhood hepatocellular carcinoma may provide a good model to study the carcinogenic potential of hepatitis B virus.     

Interferon for preventing and treating hepatocellular carcinoma associated with the hepatitis B and C viruses.

The possibility that interferon-alpha might be effective for the prevention or treatment of hepatocellular carcinoma is suggested by its efficacy against the associated hepatitis B and C viruses, by its efficacy in the treatment of some other human tumours, and by evidence that interferon-alpha may inhibit the growth of human hepatocellular carcinoma cell lines and their production of hepatitis B surface antigen. Few studies support the use of interferon-alpha for preventing hepatitis B virus-associated hepatocellular carcinoma. In contrast, benefit from the use of interferon-alpha to prevent hepatitis C virus-associated hepatocellular carcinoma is suggested in a large number of studies, but most of these studies have weaknesses of study design that preclude definitive conclusions. Nevertheless, most of these studies suggest that the incidence of hepatocellular carcinoma is lower in hepatitis C virus-infected patients receiving interferon-alpha, particularly in patients with a sustained response to interferon-alpha, compared to nonresponders. As a treatment for hepatocellular carcinoma, interferon-alpha was only evaluated in a small number of patients with advanced disease; 'partial responses' and prolongation of survival times in a few of these studies suggest that additional studies should be done in patients with less advanced disease.     

Interaction between hepatitis B and C viruses in hepatocellular carcinogenesis

Although hepatitis B (HBV) and C viruses (HCV) are, individually, major causes of hepatocellular carcinoma, the interaction, if any, between the carcinogenic effects of the two viruses is uncertain. Equal numbers of published studies have reported no risk interaction or a synergistic risk interaction. These conflicting results are explained by the rarity of concurrent infection with HBV and HCV in individuals without clinically evident liver disease, which severely limits the ability to accurately estimate the hepatocarcinogenic risk of dual infection compared with that of either infection alone. In an attempt to circumvent this difficulty, two meta-analyses have been performed, one based on studies published from a number of countries and the other on studies confined to Chinese patients. Both analyses concluded that a synergistic carcinogenic interaction existed between the two viruses and that the increased risk was super-additive but not multiplicative. If confirmed, this risk interaction will occur against a background of negative confounding effects on viral replication between HBV and HCV, which may be reciprocal. The mechanisms responsible for the carcinogenic interaction between the viruses are unknown. One possibility is that the increased incidence of cirrhosis with concurrent HBV and HCV infections acts as an even more potent tumour promoter than occurs with either virus alone. Synergism between the direct hepatocarcinogenic effects of the two viruses is another possible mechanism, but proof will have to await a fuller understanding of the pathogenetic mechanisms involved with the individual viruses.     

Hepatitis B surface antigen levels in hepatitis B virus-related hepatocellular carcinoma: a retrospective crosssectional study

正Objective To investigate the distribution of serum hepatitis B surface antigen(HBs Ag)levels in patients with hepatitis B virus(HBV)-related hepatocellular carcinoma(HCC).Methods A total of 226 cases of HBV-related HCC were collected from June 2009 to December 2013.Demographic characteristics of patients     

Hepatitis B e antigen-negative chronic hepatitis B: natural history and treatment

Hepatitis B e antigen (HBeAg)-negative chronic hepatitis B evolves in the natural history of chronic hepatitis B virus (HBV) infection linked with selection of nonproducing HBeAg but replication-competent HBV mutants, and may have a potentially severe and progressive course. Effective suppression of HBV replication is the main therapeutic target. Sustained off-therapy responses are rare with treatment of finite duration, except perhaps for interferon-based therapies, which induce such responses in a sizeable, yet small proportion of patients. Eventually, the majority of patients will be treated with long-term oral antiviral therapy, which improves patients' outcome but is associated with progressively increasing rates of viral resistance. The long-term resistance profile of adefovir is significantly better than that of lamivudine (LMV), whereas data for entecavir currently are limited to 2 years, with resistance developing in LMV-resistant but not in treatment-na?ve patients. Combination therapy with adefovir added to LMV in LMV-resistant patients is extremely effective; cases of adefovir-resistance have not been reported to date.     

Hepatitis B virus DNA prediction rules for hepatitis B e antigen-negative chronic hepatitis B

After hepatitis B e antigen (HBeAg) seroconversion, hepatitis B may become inactive or progress to HBeAg-negative hepatitis with persistent or intermittent alanine aminotransferase (ALT) elevation. The aim of this study was to prospectively identify factors predictive of the clinical course in HBeAg-negative chronic hepatitis B (CHB). Patients were stratified by ALT and HBeAg status and followed every 3 months for up to 5 years. Kaplan-Meier and Cox regression analysis using the change from normal ALT to elevated ALT as endpoints were performed to determine factors associated with ALT elevation/normalization. Seventy-four HBeAg-negative and 32 HBeAg-positive patients were prospectively evaluated. For HBeAg-negative patients, hepatitis B virus (HBV) DNA was predictive of future ALT. Only 1 patient with normal ALT and an HBV DNA value lower than 10,000 copies/mL developed an elevated ALT within the subsequent year, whereas 67% with an HBV DNA value greater than 100,000 copies/mL had a rise in ALT above normal within 1 year. Patients with a previous history of ALT elevation and longer follow-up at all levels of HBV DNA were more likely to experience ALT elevations. For HBeAg-negative patients with elevated ALT and all HBeAg-positive patients, HBV DNA did not predict future ALT. Other viral and host factors were not predictive of future ALT. CONCLUSION: HBeAg-negative CHB has a fluctuating course. HBV DNA values lower than 10,000 copies/mL predict persistently normal ALT for at least 1 year. Patients with HBV DNA values between 10,000 and 100,000 copies/mL can safely be followed at 6 monthly intervals, whereas HBV DNA values greater than 100,000 copies/mL are highly predictive of future ALT elevation and should prompt regular follow-up.     

Hepatitis B and C viral infections in patients with hepatocellular carcinoma.

The prevalence of hepatitis B and C virus infections was studied in 70 patients diagnosed as having hepatocellular carcinoma. In addition to viral serological markers, serum hepatitis B virus DNA and hepatitis C virus RNA were determined with a nested polymerase chain reaction assay. Twelve patients (17%) were HBsAg positive, 26 (37%) had antibodies to HBs, HBc or both and 32 (46%) were negative for all hepatitis B virus serological markers. Prevalence of the antibody to hepatitis C virus was 63% (44 patients). Hepatitis B virus DNA was detected in 24 of the 66 tested patients (36%). Twelve of these hepatitis B virus DNA-positive patients were HBsAg negative (seven were positive for antibody to HBs, antibody to HBc or both and five were negative for all hepatitis B virus serological markers). Hepatitis C virus RNA was found in 42 of 68 patients (62%). A high correlation (95%) existed between hepatitis C virus RNA and hepatitis C virus antibodies. Nevertheless, two patients without antibody to hepatitis C virus had serum hepatitis C virus RNA sequences. Coinfection by the two viruses was detected in nine subjects (14%), but no clinical differences were found between these and the rest of the patients. We conclude that nearly 90% (62 of the 70 patients studied) of cases of hepatocellular carcinoma in our geographical area are related to hepatitis virus infections (detected by serological or molecular studies). Hepatitis C is more prevalent than hepatitis B virus in patients with hepatocellular carcinoma, and the infection is still active when the tumor is diagnosed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hepatitis B virus DNA integration in hepatocellular carcinoma after interferon-induced disappearance of hepatitis C virus

OBJECTIVES: Hepatocellular carcinoma (HCC) has been reported in patients in whom hepatitis C virus (HCV) was eliminated by interferon (IFN) therapy. We examined the pathogenesis of HCC in patients with sustained viral response. METHODS: Operable HCC developed in 7 of 342 patients cured of HCV infection by IFN monotherapy. No patient abused alcohol or had diabetes mellitus or obesity. Resected specimens of HCC were histologically evaluated. DNA extracted from HCC was examined by polymerase chain reaction (PCR) to locate hepatitis B virus (HBV) DNA. HBV integration sites in human genome were identified by cassette-ligation-mediated PCR. RESULTS: HBV DNA was not amplified in serum samples from any of the seven patients with HCC and was found in liver in four patients. In the latter four patients, HBV DNA was integrated into the human genome of HCC. In two of these patients, covalently closed circular HBV (cccHBV) was also detected. The patients with HBV DNA integration were free of HCV for more than 3 yr. In two of the three patients without HBV DNA integration, the surrounding liver showed cirrhosis. The liver of HCC with HBV DNA integration had not progressed to cirrhosis. Three of the four tumors with HBV integration had one integration site each, located at chromosomes 11q12, 11q22-23, and 22q11, respectively. The other tumor had two integration sites, situated at chromosomes 11q13 and 14q32. At chromosome 11q12, HBV DNA was integrated into protein-coding genome, the function of which remains unclear. CONCLUSION: Integrated HBV DNA may play a role in hepatocarcinogenesis after the clearance of HCV by IFN treatment.     

Hepatitis B virus markers and antibodies to hepatitis C virus in Japanese patients with hepatocellular carcinoma

Sera from Japanese patients with chronic liver disease were tested for hepatitis B virus (HBV) markers and antibodies to hepatitis C virus (anti-HCV), and the results were correlated to the presence of hepatocellular carcinoma. In chronic non-A, non-B liver disease, anti-HCV prevalence was high both in patients with hepatocellular carcinoma (78/89, 88%) and without it (66/84, 79%), while previous HBV infection was more common in patients with hepatocellular carcinoma (65/89, 73%) than in those without it (46/84, 55%) (P<0.05). Coexistence of anti-HCV and antibodies to HBV was observed frequently in patients with hepatocellular carcinoma (56/89, 63%) compared with patients without it (39/84, 46%) (P<0.05). In chronic HBV carriers, anti-HCV was more common in patients with hepatocellular carcinoma (12/38, 32%) than in those without it (3/62, 5%) (P<0.01). These results suggest that infection with the two viruses may be a risk factor for more serious liver disease.This work was supported by a Grant-in-Aid from the Ministry of Education, Science and Culture, Japan.     

Hepatitis C and hepatocellular carcinoma

Abstract Hepatitis C virus (HCV) infection is aetiologically very closely associated with hepatocellular carcinoma (HCC). World-wide, hepatitis B virus infection is the predominant aetiological factor in developing countries, whereas in industrialized countries, HCV has a far more important role in hepatocarcinogenesis. The varying weights of the aetiological role of HCV infection are compared among countries. The speed of progression of chronic hepatitis C to cirrhosis, thenceforth to HCC, and certain discrepancies between an American study and the Japanese experience are described. The reason for the recent surge of HCV infection and subsequent increase in the incidence of HCC is also discussed. The genetic mechanism of HCV-induced hepatocarcinogenesis is still poorly understood.     

Hepatitis viruses as aetiological agents of hepatocellular carcinoma.

Hepatitis viruses, particularly HBV and HCV, are major causes of hepatocellular carcinoma worldwide, due to the induction of chronic liver disease and of cirrhotic transformation of the liver. Cirrhosis certainly represents the most important link between chronic viral hepatitis and HCC. Under these circumstances, risk of HCC development in chronic HBV and HCV infection is strictly dependent on the propensity to cirrhotic transformation. Intervention of other, more direct, molecular events induced by the virus itself are suspected, particularly for HBV which is able to integrate into the host genome, but not yet incontrovertibly proved.     

Hepatitis C and hepatocellular carcinoma

The risk of hepatocellular carcinoma (HCC) is greatly increased in patients with cirrhosis resulting from chronic hepatitis C infection. Diagnosis and treatment of HCC remain difficult and mortality is high. Surveillance of individuals who are at risk is recommended, and the risk of HCC can likely be reduced by treating the underlying hepatitis.     

High prevalence of infection with hepatitis B and C viruses in patients with hepatocellular carcinoma in Japan

BACKGROUND/AIMS: Hepatitis B and C viruses are closely associated with hepatocellular carcinoma. We studied the prevalence of infection with either virus in patients with this cancer by examination of sera and tumor tissue. METHODOLOGY: Serum samples obtained before treatment from 330 patients with hepatocellular carcinoma were assayed for antibodies against hepatitis C virus and against hepatitis B surface and core antigen. Tumor tissues from 65 patients were examined for hepatitis B virus RNA. RESULTS: Of the 330 patients, 87 had anti-hepatitis C alone; 161 had anti-hepatitis C and anti-hepatitis B (core); 13 had anti-hepatitis C and anti-hepatitis B (surface); 39 had anti-hepatitis B (surface) alone; and, 19 had anti-hepatitis B (core) alone. Eleven patients had none of these. Hepatitis B virus genes were detected in tumor tissue in all 13 patients with anti-surface antibody, in 21 of 30 patients with anti-core antibody, and in 9 of 22 patients without hepatitis B antibodies. Viral genes were detected in tumor tissue in 5 of 11 patients with neither B nor C virus markers in their sera; viral markers were found in either serum or tumor tissue in 324 of 330 patients (98.2%). CONCLUSIONS: The prevalence of hepatitis B or C virus infection in patients with hepatocellular carcinoma in Japan is extremely high. The prevalence of co-infection with both viruses is also high.