Risk for hepatocellular carcinoma with respect to hepatitis B virus genotypes B/C, specific mutations of enhancer II/core promoter/precore regions and HBV DNA levels

Prevalent HBV point mutations and mutation combinations at BCP/preC region and their association with liver disease progression

Background

Mutations in the basic core promoter (BCP) and its adjacent precore (preC) region in HBV genome are common in chronic hepatitis B patients. However, the patterns of mutation combinations in these two regions during chronic infection are less understood. This study focused on single base mutations in BCP and preC region and the multi-mutation patterns observed in chronic HBV infection patients.

Methods

Total 192 blood samples of chronic HBV infection patients were included. Direct PCR sequencing on the target region of HBV genome was successfully conducted in 157 samples. The rest 35 samples were analyzed by clone sequencing. Only the nucleotide substitutions with their frequencies no less than 10% were included in multi-mutation analysis with the exception for the polymorphic sites between genotypes B and C.

Results

Five high frequency mutations (≥10%) were found in BCP and preC region. Thirteen types of multi-mutations in one fragment were observed, among which 3 types were common combinations (≥5%). The top three multi-mutations were A1762T/G1764A (36%), A1762T/G1764A/G1896A (11%) and T1753(A/C)/A1762T/G1764A/G1896A (8%). Patients with multi-mutations in viral genomes (≥3) were more likely to have liver cirrhosis or hepatocellular carcinoma (OR = 3.1, 95% CI: 1.6-6.0, P = 0.001). G1896A mutation seemed to be involved in liver disease progression independent of the patient age (OR = 3.6, 95% CI: 1.5-8.6; P = 0.004). In addition, patients with more viral mutations detected (≥3) were more likely to be HBeAg negative (OR = 2.7, 95% CI: 1.1-6.4; P = 0.027). Moreover, G1776A mutation was shown to contribute to HBeAg negativity in our study (OR = 8.6, 95% CI: 1.2-44.9; P = 0.01).

Conclusions

Patients with advanced liver diseases and with HBeAg negativity more likely have multi-mutations in HBV genomes but with different mutation combination patterns. G1896A mutation appears to be independent of infection history.

Comparison study on the complete sequence of hepatitis B virus identifies new mutations in core gene associated with hepatocellular carcinoma

BACKGROUND

Mutations in the hepatitis B virus (HBV) genome may influence the activity of liver disease. The aim of this study was to identify new viral variations associated with hepatocellular carcinoma (HCC).

METHODS

We carried out a comparison study on the complete sequence of HBV isolated from 20 HCC and 35 non-HCC patients in Qidong, China, an area with a high incidence of HCC. We compared the HBV sequences in a consecutive series of plasma samples from four HCC cases before and after the occurrence of HCC. In addition, we selected four mutations in the HBV core (C) gene to verify their relationships to HCC in an independent set of 103 HCC cases and 103 sex- and age-matched non-HCC controls.

RESULTS

The pre-S deletion and 12 point mutations, namely, the pre-S2 start codon mutation, T53C in the pre-S2 gene, T766A in the S gene, G1613A, C1653T, A1762T, G1764A in the X gene, and G1899A, C2002T, A2159G, A2189C, and G2203W (A or T) in the pre-C/C gene, showed close associations with HCC. In the validation study, A2159G, A2189C, and G2203W showed consistent associations with HCC by univariate analysis. Multivariate analysis showed that A2189C and G2203W were independent risk factors for HCC. The odds ratios (95% confidence interval) were 3.99 (1.61-9.92) and 9.70 (1.17-80.58), respectively, for A2189C and G2203W.

CONCLUSIONS

These results implicate A2189C and G2203W as new predictive markers for HCC.

IMPACT

The complete genome analysis of HBV provided pilot data for the identification of novel mutations that could serve as markers for HCC.

A case-control study on sequence variations in the enhancer II/core promoter/precore and X genes of hepatitis B virus in patients with hepatocellular carcinoma

PURPOSE

To evaluate the sequence variations in the enhancer II (EnhII)/basal core promotor (BCP)/precore (PC) and X genes of hepatitis B virus (HBV) in Thai patients with hepatocellular carcinoma (HCC) by conducting a cross-sectional case-control study.

METHODS

As much as 60 patients with HCC and 60 patients without HCC, who were matched for sex, age, hepatitis B e antigen (HBeAg) status, and HBV genotype, were included. Viral mutations in the EnhII/BCP/PC and X regions were characterized by direct sequencing in serum samples.

RESULTS

The prevalence of T1753C/A, A1762T/G1764A and G1899A mutations were significantly higher in the HCC group compared to the non-HCC group (43.3 vs. 23.3%, P = 0.02; 88.3 vs. 53.0%, P < 0.001; and 35.0 vs. 8.3%, P = 0.001, respectively). No significant difference between groups was found with respect to G1613A, C1653T, C1766T/T1768A, A1846T/C, T1858C, and G1896A mutations. By multiple logistic regression analysis, the presence of cirrhosis, A1762T/G1764A and G1899A mutations were independently associated with the risk of HCC.

CONCLUSION

These data suggested that A1762T/G1764A and G1899A mutations were associated with the development of HCC in Thai patients.

Does chemotherapy prevent HBV-related hepatocellular carcinoma? Cons

The retrospective scrutiny of studies that were originally designed to assess the antiviral activity of interferon (IFN) and nucleos(t)ide analogues (NUC) suggested reduced incidence of hepatocellular carcinoma (HCC) in responders. The interpretation of these studies, however, is questioned by the heterogeneity of patient referral, adoption of surrogate end-points, lack of control arms and, overall, by the lack of power to capture enough hard end-points of the natural history of hepatitis B, including HCC. Another point of criticism is that above all, IFN studies could have been affected by study enrolment skewed towards patients with less advanced liver disease, who had a better predicted compliance to therapy but a lower risk of developing HCC in the short-term. In my opinion, these constraints coupled with the lack of patient stratification by HCC predictors, make the evaluation of the prophylactic activity of IFN and NUC even more difficult. Overall, while single studies provide some evidence for a reduced HCC incidence in virological responders, particularly in those with moderate liver fibrosis, we still lack confirmation that anti-HBV therapy prevents HCC in patients with an established cirrhosis, too. Finally, tertiary prevention with anti-HBV treatments is controversial, due to the existence of a few, methodologically flawed studies.

Factors affecting the changes in molecular epidemiology of acute hepatitis B in a Southern Italian area

To explore changes in molecular epidemiology of acute viral hepatitis B (AVH-B), hepatitis B virus (HBV) genotypes were determined by direct sequencing of the Pre-S-S region in 123 consecutive patients, with AVH-B observed in Naples or its surroundings in the last decade (group AVH-B) and in 123 HBV chronic carriers [chronic carrier of HBV (CC-B) group] from the same areas, who had been hepatitis B surface antigen-positive for more than 10 years. Genotype D was less frequently detected in patients with AVH-B than in those in the CC-B group (76.4%vs 97.5%, P < 0.0001). In the AVH-B group, intravenous drug addiction (IVDA) was the prevalent risk factor (55.3%) for acquiring HBV in the 94 patients with HBV genotype D, but it was rarely recorded (6.9%) in the 29 patients with genotypes non-D (P < 0.0001); unsafe sexual intercourse was prevalent in patients with genotype non-D (72.3%) and less frequent in those with genotype D (28.8%, P < 0.005). In the AVH-B group, the prevalence of non-D genotypes increased during the observation period from 11.1% in 1999-2003 to 41.1% in 2004-2008 (P < 0.0005), paralleling the increase in the prevalence of patients with unsafe sexual intercourse; similarly, the progressive decrease in IVDA paralleled the decrease in the prevalence of genotype D (from 88.3% in 1999-2003 to 11.7% in 2004-2008). The prevalence of HBV non-D genotypes recorded in the last 10 years in AVH-B in this area shows a progressive increase, most probably because of recent changes in HBV epidemiology, namely, the HBV mass vaccination campaign and increased immigration from areas with high HBV endemicity.

Hepatocellular carcinoma in non-cirrhotic liver: a reappraisal

Although not frequently, hepatocellular carcinoma (HCC) can ensue in a non-cirrhotic liver. As compared to cirrhotic HCC, this kind of tumour has some peculiarities, such as: (a) a lower male preponderance and a bimodal age distribution; (b) a lower prevalence of the three main risk factors (hepatitis B and C virus infections and alcohol abuse), with an increased prevalence of other etiologic factors, such as exposure to genotoxic substances and sex hormones, inherited diseases, genetic mutations; (c) a more advanced tumour stage at the time of diagnosis, as it is usually detected due to the occurrence of cancer-related symptoms, outside any scheduled surveillance program; (d) a much higher amenability to hepatic resection, due to the low risk of liver failure even after extended parenchymal mutilation; (e) overall and disease-free survivals after resection of non-advanced tumours (meeting the Milano criteria) comparable to that obtained with liver transplantation in cirrhotic patients carrying an early tumour; (f) overall survival strictly dependent on tumour burden (and its recurrence) and barely influenced by liver function.

T1653 mutation in the enhancer II region of the hepatitis B virus genome in southern African Blacks with hepatocellular carcinoma

BACKGROUND

An increased incidence of C-to-T1653 transversion (T1653) in the enhancer II region of the core promoter of hepatitis B virus has been reported in Japanese and Chinese patients with hepatocellular carcinoma infected with genotypes B or C of the virus, but little information is available in patients infected with other genotypes.

AIM

To document the prevalence of T1653 in Black Africans with hepatocellular carcinoma, in whom genotype A is the dominant genotype and subgenotype A1 the dominant subgenotype, and to correlate its presence with other core promoter mutations previously described in association with T1653.

METHODS

The presence of the mutations was determined in 84 patients with hepatitis B virus-induced hepatocellular carcinoma and 50 matched asymptomatic carriers of the virus by extracting viral DNA from serum, amplification by polymerase chain reaction assay, and nucleotide sequencing.

RESULTS

T1653 was not found significantly more often in the cancer patients with genotype A and subgenotype A1 than in the controls. An association was found not only between T1653 and T1762, A1764 and dual T1762/A1764 in the patients with hepatocellular carcinoma, but also in the asymptomatic carriers.

CONCLUSION

T1653 mutation of hepatitis B virus does not occur more often in Black African patients with hepatocellular carcinoma with genotype A and subgenotype A1 than in asymptomatic carriers of the virus. No correlation specific to hepatocellular carcinoma was found between T1653 and other core promoter mutations in these patients. The presence of the T1653 mutation did not influence the e antigen status of the patients.

Hepatocellular carcinoma in African Blacks: Recent progress in etiology and pathogenesis

Occult hepatitis B virus (HBV) infection was shown to be present in 75% of Black Africans with hepatocellular carcinoma (HCC) in whom the tumor was hitherto not thought to be caused by chronic HBV infection. The association between chronic HBV infection and the development of the tumor is thus even closer than was originally thought. HBV viral load was found to be significantly higher in patients with HCC than in Black African controls. As in other populations, HBV e antigen-positive patients with hepatocellular carcinoma had significantly higher viral loads than patients negative for this antigen. The significance of this finding is discussed. The risk for HCC development with genotype A of HBV, the predominant genotype in African isolates, has not been investigated. Genotype A was shown to be 4.5 times more likely than other genotypes to cause HCC in Black Africans, and tumours occurred at a significantly younger age. Increasing numbers of patients with human immunodeficiency virus (HIV) and HBV co-infection are being reported to develop HCC. A preliminary case/control comparison supports the belief that HIV co-infection enhances the hepatocarcinogenic potential of HBV. A study from The Gambia provides the first evidence that dietary exposure to aflatoxin B(1) may cause cirrhosis and that this may play a contributory role in the pathogenesis of aflatoxin-induced HCC. An animal model has provided experimental support for the clinical evidence that dietary iron overload in the African is directly hepatocarcinogenic, in addition to causing the tumor indirectly through the development of cirrhosis.

Chronic hepatitis B: whom to treat and for how long? Propositions, challenges, and future directions

Recent guidelines of the American Association for the Study of Liver Diseases, the European Association for the Study of the Liver, and the Asian Pacific Association for the Study of the Liver 2008 update of the "Asian-Pacific consensus statement on the management of chronic hepatitis B" offer comprehensive recommendations for the general management of chronic hepatitis B (CHB). These recommendations highlight preferred approaches to the prevention, diagnosis, and treatment of CHB. Nonetheless, the results of recent studies have led to an improved understanding of the disease and a belief that current recommendations on specific therapeutic considerations, including CHB treatment initiation and cessation criteria, particularly in patient populations with special circumstances, can be improved. Twelve experts from the Asia-Pacific region formed the Asia-Pacific Panel Recommendations for the Optimal Management of Chronic Hepatitis B (APPROACH) Working Group to review, challenge, and assess relevant new data and inform future updates of CHB treatment guidelines. The significance of and controversy about reported findings were discussed and debated in an expert meeting of the Working Group in Beijing, China, in November 2008. This review paper attempts to identify areas requiring improved CHB management and provide suggestions for future guideline updates, with special emphasis on treatment initiation and duration.

Distribution and hepatocellular carcinoma-related viral properties of hepatitis B virus genotypes in Mainland China: a community-based study

INTRODUCTION

Hepatitis B virus (HBV) genotypes, replication status, and mutations have been associated with the risk of hepatocellular carcinoma (HCC). Our aim was to study the distribution and HCC-related viral properties of HBV genotypes/subgenotypes in Mainland China.

METHODS

A multistage cluster probability sampling method was applied to select 81,775 participants between 1 and 59 years at 160 national disease surveillance points. We examined hepatitis B surface antigen, HBV genotypes and subgenotypes, hepatitis B e antigen, viral load, and mutations in the PreS and core promoter regions of HBV genome.

RESULTS

HBV subgenotypes B2 (27.3%), C1 (10.7%), and C2 (58.0%) were predominant. Genotype D (D1, 80.8%) was frequent in the Uygur. We identified a new subgenotype, C9, mainly in Tibetans. Compositions of subgenotypes B2 and C1 and genotype mixture increased from the North to Central South, which was consistently associated with the increasing prevalence of hepatitis B surface antigen. Hepatitis B e antigen positivity and viral loads were higher in the young with genotype B and declined more rapidly with increasing age than those with genotype C. In contrast to G1896A, PreS deletion, T31C, T1753V, and A1762T/G1764A were more frequent in subgenotype C2 than in subgenotype B2. A1762T/G1764A, T1753V, C1653T, and G1896A, except PreS deletion, consecutively increased with increasing age.

CONCLUSION

HBV subgenotypes B2, C1, and C2 are endemic in Mainland China. HBV genotype C exhibits less replication activity in the young and harbors higher frequencies of the HCC-associated mutations than genotype B.

IMPACT

These basic data could help evaluate the association of HBV variations with HCC.

Clinical relevance and public health significance of hepatitis B virus genomic variations

Ten hepatitis B virus (HBV) genotypes (A-J) and 34 HBV subgenotypes have been identified so far. HBV genotypes and subgenotypes have distinct geographical distributions, and have been shown to differ with regard to clinical outcome, prognosis, and response to interferon treatment. Infection with subgenotype A2 is frequently associated with high viral load, resulting in acute infection via horizontal transmission. Genotypes A and B are more sensitive to interferon treatment than genotypes D and C, respectively. Genotype B is more frequent in acute hepatitis than genotype C, whereas genotype C (C2) is more frequently associated with an increased risk of hepatocellular carcinoma (HCC), mostly cirrhotic, as compared with genotype B (B2). Genotype mixture is associated with high viral load and worse outcome of HBV infection. HBV mutations in the S genes, especially amino acids substitution at position 145 (G145R), are associated with immune escape, whereas mutations in the PreS or S genes which impair HBsAg secretion could present a risk to blood safety. HBV variants harboring mutations in the viral polymerase gene that confer resistance to nucleoside analogs may be selected during antiviral therapy. Different genotypes have distinct mutation patterns in the PreS and EnhII/BCP/Precore regions. PreS deletions, C1653T, T1753V, and A1762T/G1764A are associated with an increased risk of HCC. HCC-associated HBV mutants may not transmit via mother-to-child transmission, and are likely generated during HBV-induced pathogenesis. Examination of HBV mutations alone or in combination and host genetic susceptibility will be helpful in classifying the HBV-infected subjects who will develop HCC and need active anti-viral treatments.

Geographical and genetic diversity of the human hepatitis B virus

Hepatitis B virus (HBV) is one of the most widely distributed viruses that infect humankind. Distinct clinical and virological characteristics of the HBV-infection have been reported in different geographical parts of the world and are increasingly associated with genetic diversity of the infecting virus. HBV is classified into genotypes and subgenotypes that are associated with ethnicity and geography. The genetic diversity of HBV in its various aspects has been the subject of extensive investigations during the last few decades. Since molecular epidemiology research tools have become widely available, the number of new publications in this field has grown exponentially. This review summarises the recent publications on the geographical distribution of genetic variants of HBV, and proposes updated criteria for the identification of new genotypes and subgenotypes of the virus.

Clinical relevance and public health significance of hepatitis B virus genomic variations

Ten hepatitis B virus (HBV) genotypes (A-J) and 34 HBV subgenotypes have been identified so far. HBV genotypes and subgenotypes have distinct geographical distributions, and have been shown to differ with regard to clinical outcome, prognosis, and response to interferon treatment. Infection with subgenotype A2 is frequently associated with high viral load, resulting in acute infection via horizontal transmission. Genotypes A and B are more sensitive to interferon treatment than genotypes D and C, respectively. Genotype B is more frequent in acute hepatitis than genotype C, whereas genotype C (C2) is more frequently associated with an increased risk of hepatocellular carcinoma (HCC), mostly cirrhotic, as compared with genotype B (B2). Genotype mixture is associated with high viral load and worse outcome of HBV infection. HBV mutations in the S genes, especially amino acids substitution at position 145 (G145R), are associated with immune escape, whereas mutations in the PreS or S genes which impair HBsAg secretion could present a risk to blood safety. HBV variants harboring mutations in the viral polymerase gene that confer resistance to nucleoside analogs may be selected during antiviral therapy. Different genotypes have distinct mutation patterns in the PreS and EnhII/BCP/Precore regions. PreS deletions, C1653T, T1753V, and A1762T/G1764A are associated with an increased risk of HCC. HCC-associated HBV mutants may not transmit via mother-to-child transmission, and are likely generated during HBV-induced pathogenesis. Examination of HBV mutations alone or in combination and host genetic susceptibility will be helpful in classifying the HBV-infected subjects who will develop HCC and need active anti-viral treatments.

X gene mutations in hepatitis B patients with cirrhosis, with and without hepatocellular carcinoma

Specific mutations in the hepatitis B virus (HBV) genome have been reported to be associated with the development of hepatocellular carcinoma (HCC). The goal of this study was to determine whether mutations in the HBV X gene are associated with the development of HCC in hepatitis B patients with cirrhosis. Forty-two patients infected with HBV genotype C2 with cirrhosis and HCC were compared with 46 patients with cirrhosis but without HCC. X gene mutations were determined by direct sequencing in all patients. The HCC and non-HCC groups were similar with respect to clinical characteristics, and the presence of T1762/A1764, T1653, and V1753 mutations was not significantly different between the two groups (P = 0.068, P = 0.097, P = 0.442, respectively). Only the B1499 mutation was associated significantly with HCC (P = 0.015) (odds ratio: 3.42, 95% CI: 1.24-9.48). In hepatitis Be antigen (HBeAg)-positive patients, advanced age was associated significantly with HCC (P = 0.038), whereas in HBeAg-negative patients, the B1499 mutation was associated more significantly with HCC (P = 0.01). Patients in the B1499 mutation group exhibited significantly higher AST and ALT levels compared with patients infected the wild-type virus. In conclusion, B1499 is a novel mutation associated with HCC in Korean patients with cirrhosis infected with HBV genotype C2.

Hepatitis B viral loads in southern African Blacks with hepatocellular carcinoma

Although viral loads are known to influence the development of hepatitis B virus-induced hepatocellular carcinoma in a number of populations, little information is available in the Black African population. Black African patients with hepatocellular carcinoma differ from those in other populations in having a lower frequency of e antigen-positivity and in other respects that might affect viral loads. Hepatitis B viral loads were measured using real-time polymerase chain reaction assay in 124 Black Africans with hepatocellular carcinoma and compared with those in 125 Black adult asymptomatic viral carriers. The geometric mean viral load in the cancer patients was 553,618 copies/ml (95% CI 301,953-1,015,033 copies/ml), with 62.1% having loads >1 x 10(5) copies/ml and 87.1% >1 x 10(4) copies/ml, whereas that in the carriers was 16,084 copies/ml (95% CI 9,184-28,168 copies/ml), with only 15.2% having values >1 x 10(5) copies/ml and 49.6% >1 x 10(4) copies/ml (P < 0.001 in each instance). Mean viral load was significantly higher in e antigen-positive than e antigen-negative cancer patients (5,905,357 copies/ml [1,362,847-25,588,520] cf 238,173 copies/ml [97,200-685,730]: P < 0.001) after adjusting for age and sex. No statistically significant difference existed between patients in different age groups, in men and women, or in patients infected with genotype A or D after adjusting for the other variables.

CONCLUSION

Black Africans with hepatocellular carcinoma have high hepatitis B viral loads in spite of the relative infrequency of e antigen-positivity.

Low pretreatment serum HBsAg level and viral mutations as predictors of response to PEG-interferon alpha-2b therapy in chronic hepatitis B

BACKGROUND

Viral genomic mutations have become increasingly recognized as being associated with the outcome of chronic HBV infection. However, the role of viral mutations as a predictor of response to pegylated-interferon (PEG-IFN) therapy has so far remained unclear.

STUDY DESIGN

Viral mutations in the enhancer II/basal core promoter (BCP)/precore and the pre-S regions were characterized by direct sequencing in pretreatment serum samples of 50 patients with chronic hepatitis B (33 HBeAg-positive and 17 HBeAg-negative), who were treated for 48 weeks with PEG-IFN alpha-2b.

RESULTS

Sustained virological response at 48 weeks post treatment, defined as HBeAg seroconversion and HBV DNA<2000IU/mL for HBeAg-positive patients, and HBV DNA<200IU/mL for HBeAg-negative patients, was achieved in 12 (36.4%) and 6 (35.3%) of HBeAg-positive and HBeAg-negative patients, respectively. Response to PEG-IFN therapy correlated to low pretreatment HBsAg level but did not correlate with HBV genotype, pretreatment alanine transaminase and HBV DNA levels. In HBeAg-positive hepatitis, PEG-IFN response correlated with the appearance of double BCP mutations (A1762T/G1764A) at baseline (P=0.041). In the HBeAg-negative group, response to PEG-IFN therapy was associated with the presence of pre-S mutation/deletions (P=0.028). Multivariate analysis identified low pretreatment HBsAg level as an independent factor associated with SVR in both groups.

CONCLUSIONS

Pretreatment quantitative HBsAg determination is useful for predicting response to PEG-IFN therapy. The presence of double BCP and pre-S mutation/deletions at entry may be associated with a high rate of antiviral response in HBeAg-positive and HBeAg-negative hepatitis, respectively.

Associations between hepatitis B virus mutations and the risk of hepatocellular carcinoma: a meta-analysis

Background

The association between hepatitis B virus (HBV) mutations and hepatocarcinogenesis remains controversial because of conflicting data in the literature. We conducted a meta-analysis of case–control and cohort studies to examine HBV PreS, enhancer II (EnhII), basal core promoter (BCP), and precore mutations in relation to the risk of hepatocellular carcinoma (HCC).

Methods

We searched databases for studies of these associations that were published in English or Chinese up to August 31, 2008. HBV mutation–specific odds ratios and relative risks were pooled by use of a random-effects model and stratified by potential confounders. All statistical tests were two-sided.

Results

Of the 43 studies included in this meta-analysis, 40 used a case–control design. The 43 studies evaluated a total of 11 582 HBV-infected participants, of whom 2801 had HCC. Statistically significant summary odds ratios of HCC were obtained for any PreS mutation (3.77, 95% confidence interval [CI] = 2.57 to 5.52), C1653T in EnhII (2.76, 95% CI = 2.09 to 3.64), T1753V (2.35, 95% CI = 1.63 to 3.40), and A1762T/G1764A in BCP (3.79, 95% CI = 2.71 to 5.29). PreS mutations were more strongly associated with an increased risk of HCC in subjects who were infected with HBV genotype C than in those who were infected with HBV genotype B, whereas the opposite was true for A1762T/G1764A. C1653T, T1753V, and A1762T/G1764A were more strongly associated with an increased risk of HCC in hepatitis B e antigen (HBeAg)–positive subjects than in HBeAg-negative subjects. PreS mutations, C1653T, T1753V, and A1762T/G1764A accumulated during the progression of chronic HBV infection from the asymptomatic carrier state to HCC (P_trend < .001 for each mutation). PreS mutations, C1653T, C1653T + T1753V, and A1762T/G1764A-based combinations of mutations had specificities greater than 80% for the prediction of HCC. The precore mutations G1896A and C1858T were not associated with the risk of HCC, regardless of HBeAg status and HBV genotype.

Conclusions

HBV PreS mutations, C1653T, T1753V, and A1762T/G1764A are associated with an increased risk of HCC. These mutations alone and in combination may be predictive for hepatocarcinogenesis.

Associations between hepatitis B virus mutations and the risk of hepatocellular carcinoma: a meta-analysis

BACKGROUND

The association between hepatitis B virus (HBV) mutations and hepatocarcinogenesis remains controversial because of conflicting data in the literature. We conducted a meta-analysis of case-control and cohort studies to examine HBV PreS, enhancer II (EnhII), basal core promoter (BCP), and precore mutations in relation to the risk of hepatocellular carcinoma (HCC).

METHODS

We searched databases for studies of these associations that were published in English or Chinese up to August 31, 2008. HBV mutation-specific odds ratios and relative risks were pooled by use of a random-effects model and stratified by potential confounders. All statistical tests were two-sided.

RESULTS

Of the 43 studies included in this meta-analysis, 40 used a case-control design. The 43 studies evaluated a total of 11 582 HBV-infected participants, of whom 2801 had HCC. Statistically significant summary odds ratios of HCC were obtained for any PreS mutation (3.77, 95% confidence interval [CI] = 2.57 to 5.52), C1653T in EnhII (2.76, 95% CI = 2.09 to 3.64), T1753V (2.35, 95% CI = 1.63 to 3.40), and A1762T/G1764A in BCP (3.79, 95% CI = 2.71 to 5.29). PreS mutations were more strongly associated with an increased risk of HCC in subjects who were infected with HBV genotype C than in those who were infected with HBV genotype B, whereas the opposite was true for A1762T/G1764A. C1653T, T1753V, and A1762T/G1764A were more strongly associated with an increased risk of HCC in hepatitis B e antigen (HBeAg)-positive subjects than in HBeAg-negative subjects. PreS mutations, C1653T, T1753V, and A1762T/G1764A accumulated during the progression of chronic HBV infection from the asymptomatic carrier state to HCC (P(trend) < .001 for each mutation). PreS mutations, C1653T, C1653T + T1753V, and A1762T/G1764A-based combinations of mutations had specificities greater than 80% for the prediction of HCC. The precore mutations G1896A and C1858T were not associated with the risk of HCC, regardless of HBeAg status and HBV genotype.

CONCLUSIONS

HBV PreS mutations, C1653T, T1753V, and A1762T/G1764A are associated with an increased risk of HCC. These mutations alone and in combination may be predictive for hepatocarcinogenesis.

Specific mutations in the enhancer II/core promoter/precore regions of hepatitis B virus subgenotype C2 in Korean patients with hepatocellular carcinoma

Recently, hepatitis B virus (HBV) genotypes and mutations have been reported to be related to hepatocellular carcinoma (HCC). This cross-sectional case-control study examined the relationship between HCC and mutations in the enhancer II/core promoter and precore regions of HBV by comparing 135 Korean HCC patients infected with HBV genotype C2 (HBV/C2; HCC group) with 135 age-, sex-, and hepatitis B e antigen (HBeAg) status-matched patients without HCC (non- HCC group). Age and sex were also matched between HBeAg-positive and -negative patients. The prevalence of T1653, A1689, V1753, T1762/A1764, T1846, A1850, C1858, and A1896 mutations was evaluated in this population. The prevalence of the T1653 mutation in the box alpha region, the T1689 [corrected] mutation in between the box alpha and beta regions, and the T1762/A1764 mutations in the basal core promoter region was significantly higher in the HCC group compared to the non-HCC group (8.9% vs. 2.2%, P = 0.017; 19.3% vs. 4.4%, P < 0.001; and 60.7% vs. 22.2%; P < 0.001). Among HBeAg-negative patients, the frequency of the T1653 mutation was higher in the HCC group. Regardless of HBeAg status, the prevalence of the T1689, [corrected] and T1762/A1764 mutations was higher in the HCC group than in the non-HCC group. However, no association was observed between mutations in the precore region and HCC. Upon multivariate analysis, the presence of the T1653, T1689, [corrected] and T1762/A1764 mutations was an independent predictive factor for HCC. The addition of the T1653 or T1689 [corrected] mutation to T1762/A1764 increased the risk of HCC. In conclusion, the T1653, T1689, [corrected] and/or T1762/A1764 mutations were associated with the development of HCC in Korean patients infected with HBV/C2.

[Hepatitis B virus genetic diversity and mutant]

Hepatitis B virus (HBV) is a partially double stranded DNA virus with genetic diversity represented by eight genotypes (A to H). Natural course and response to treatment could be affected by HBV genotypes. HBV shows high rates of turn over in the absence of proof-reading ability. As a result, large amounts of quasispecies are produced naturally or antiviral-associated. HBV consists of four open reading frames, namely preS/S gene, precore/core gene, polymerase gene, and X gene. Mutations on preS gene can result in undetectable HBsAg even in case that HBV is replicating. Surface gene mutation leads to decreased binding affinity to anti-HBs, which is associated with a vaccine escape mutant. Precore mutation abolishes HBeAg whereas mutations on basal core promoter gene down-regulate the HBeAg production. Mutations on basal core promoter are associated with increased HBV replication and high incidence of progressive liver diseases such as liver cirrhosis and hepatocellular carcinoma. Mutations on polymerase genes are often induced by antiviral therapy. Emergence of antiviral-resistant mutation is the major cause of treatment failure. Furthermore, existence of prior antiviral-resistant mutations limits the options of subsequent antiviral agents. Therefore, judicious use of antivirals and selection of the most potent drug with the lowest resistance rate are of the utmost importance for the prevention of antiviral-associated mutants. Detailed knowledge and understanding of HBV genetic diversity and mutant would be critical to establish strategies for the diagnosis and management of HBV infection.

Hepatitis B virus pre-S deletion mutations are a risk factor for hepatocellular carcinoma: a matched nested case-control study

A matched nested case-control study of 33 paired cases and controls was conducted, based on a study cohort in Long An county, Guangxi, China, to determine whether infection with hepatitis B virus (HBV) with pre-S deletions is independently associated with the development of hepatocellular carcinoma (HCC), without the confounding effects of basal core promoter (BCP) double mutations. The prevalence of pre-S deletions was significantly higher in HCC (45.5 %, 15 of 33) than the controls (18.2 %, 6 of 33) (P<0.01), under the control of the influence of BCP double mutations. Most of the pre-S deletions occurred in, or involved, the 5' half of the pre-S2 region and the difference between HCC (93.3 %, 14 of 15) and controls (66.7 %, four of six) was significant for this region (P=0.015). There was no significant difference in pre-S deletions between the BCP mutant group and BCP wild-type group (P>0.05), nor was the prevalence of pre-S deletions significantly different between genotypes B and C (P>0.1). These results suggest that pre-S deletions constitute an independent risk factor for HCC and their emergence and effect are independent of BCP mutations. The 5' terminus of pre-S2 is the favoured site for the deletion mutations, especially in HCC cases. Further prospective studies are required to confirm the role of these mutations in the development of HCC.

Independent risk factors and predictive score for the development of hepatocellular carcinoma in chronic hepatitis B

BACKGROUND/AIMS

To determine whether gender, age, hepatitis B virus genotype, core promoter and precore mutations, HBeAg/ anti-HBe status, HBV DNA, ALT levels and cirrhosis on presentation were independent risk factors and derive a novel risk score for the development of HCC.

METHODS

CHB patients (820) were followed up (mean duration 76.8 months) for the occurrence of HCC.

RESULTS

The 5- and 10-year prevalence of HCC were 4.4% and 6.3%, respectively. Cox regression analysis showed that male gender (p = 0.025, RR 2.98), increasing age (p < 0.001, RR 1.07), higher HBV DNA levels (p = 0.02, RR 1.28), core promoter mutations (p = 0.007, RR 3.66), and presence of cirrhosis (p < 0.001, RR 7.31) were independent risks for the development of HCC. A risk score was derived and validated with sensitivity > 84% and specificity > 76% to predict the 5- and 10- year risks for the development of HCC. The AUC for the 5- and 10-year prediction were 0.88 and 0.89, respectively.

CONCLUSIONS

The risk score, based on age, gender, HBV DNA levels, core promoter mutations and cirrhosis, can estimate the chance of development of HCC in 5 and 10 years after presentation. It can be used to identify high-risk CHB patients for treatment and screening of HCC.

Sequential accumulation of the mutations in core promoter of hepatitis B virus is associated with the development of hepatocellular carcinoma in Qidong, China

BACKGROUND/AIMS

To investigate the mutations in hepatitis B virus (HBV) that might be related to hepatocellular carcinoma (HCC) in the high-risk area Qidong, China.

METHODS

DNA sequences of HBV basal core promoter (BCP) and the overlapping X gene were determined in 58 HCC and 71 chronic hepatitis (CH) patients. In addition, a consecutive series of plasma samples from 15 HCC cases were employed to compare the CP/X sequences before and after the occurrence of HCC.

RESULTS

T1762/A1764 double mutation was frequently found in Qidong patients, regardless of clinical status (65.5% in HCC and 73.2% in CH, P>0.05). Unexpectedly, the adjacent T1766/A1768 mutation significantly increased the risk of HCC (P<0.05). Moreover, the prevalence of triple mutations in BCP was significantly higher in patients with HCC than those with CH (P<0.05). The longitudinal study demonstrated that the mutations in BCP were gradually accumulated during the development of HCC. Colony formation assay showed while A1764 mutation alone did not alter the colony-inhibitory activity of HBx, double or triple mutations largely abrogated this effect.

CONCLUSIONS

The complex mutation involving T1766/A1768 was closely related to HCC. The enhanced risk of HCC caused by BCP variants could be attributable partially to the aberrant activity of HBx.

HBV A1762T, G1764A mutations are a valuable biomarker for identifying a subset of male HBsAg carriers at extremely high risk of hepatocellular carcinoma: a prospective study

OBJECTIVES

Surveillance of hepatocellular carcinoma (HCC) can detect small tumors for resection but at a huge cost of health resources. The challenge is to reduce the surveillance population. We reported that 96% of HCC patients but only 24% of controls were infected with the hepatitis B virus (HBV) with A(1762)T, G(1764)A mutations in Guangxi, China. It is likely to be extremely beneficial in terms of cost and resources if a significant number of tumors can be detected early by screening this selected population. Our aim is to test this hypothesis.

METHODS

A cohort of 2,258 hepatitis B surface antigen-positive subjects aged 30-55 yr was recruited in Guangxi. Following evaluation of virological parameters at baseline, HCC is diagnosed by 6-monthly measurements of serum alpha-fetoprotein levels and ultrasonographic examinations.

RESULTS

Sixty-one cases of HCC were diagnosed after 36 months of follow-up. The HCC rate was higher in the mutant than wild-type group (P < 0.001, rate ratio [RR] 6.23, 95% confidence interval [CI] 2.83-13.68). The HCC rate in the male mutant group was higher than that in the male wild-type group (P < 0.001, RR 11.54, 95% CI 3.58-37.24). Specifically, 93.3% of male cases are infected with the mutant. Multivariate analyses showed that in men, increasing age and A(1762)T, G(1764)A double mutations are independently associated with developing HCC.

CONCLUSIONS

HBV A(1762)T, G(1764)A mutations constitute a valuable biomarker to identify a subset of male HBsAg carriers aged >30 yr at extremely high risk of HCC in Guangxi, and likely elsewhere.

Hepatocellular carcinoma: epidemiology and clinical aspects

Liver cancer is one of the most frequent solid cancers that kills more than 650,000 people around the world each year. Though great improvements have been done in last 10 years on the understanding the molecular mechanisms involved in liver oncogenesis, the prognosis of patients affected by liver cancer is still poor for most of them. Even in those where a relatively early diagnosis is done, the course of the disease is often fatal due to the underlying liver cirrhosis. In this review authors report the most recent findings on the pathogenesis of liver cancer and on therapeutic approaches, included those emerging from the most recent literature.

Role of viral factors in the natural course and therapy of chronic hepatitis B

Hepatitis B virus (HBV) infection is a global health problem that causes a wide spectrum of liver disease, including acute or fulminant hepatitis, inactive carrier state, chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). The pathogenesis of hepatocyte damage associated with HBV is mainly through immune-mediated mechanisms. On the basis of the virus and host interactions, the natural history of HBV carriers who are infected in early life can be divided into four dynamic phases. The frequency, extent, and severity of hepatitis flares or acute exacerbation in the second immune clearance and/or fourth reactivation phase predict liver disease progression in HBV carriers. In the past decade, hepatitis B viral factors including serum HBV DNA level, genotype, and naturally occurring mutants predictive of clinical outcomes have been identified. The higher the serum HBV DNA level after the immune clearance phase, the higher the incidence of adverse outcomes over time. In addition, high viral load, genotype C, basal core promoter mutation, and pre-S deletion correlate with increased risk of cirrhosis and HCC development. As to the treatment of chronic hepatitis B, patients with high HBV DNA level and genotype C or D infection are shown to have a worse response to interferon therapy. In conclusion, serum HBV DNA level, genotype, and naturally occurring mutants are identified to influence liver disease progression and therapy of chronic hepatitis B. More investigations are needed to clarify the molecular mechanisms of the viral factors involved in the pathogenesis of each stage of liver disease and the response to antiviral treatments.