Effect of combined mutations in the enhancer II and basal core promoter of hepatitis B virus on development of hepatocellular carcinoma in Qidong, China.

AIM: To investigate the roles of mutations in enhancer II (Enh II), basal core promoter (BCP) and precore (PC) regions of hepatitis B virus (HBV) in the progression of hepatocellular carcinoma (HCC) in Qidong, China. METHODS: We conducted a case-control study within a cohort of 2387 male HBV carriers who were recruited between August and September 1996. The HBV DNA sequence was determined in 152 HCC and 131 chronic hepatitis patients. Mutation exchanges during follow up in 115 cases were compared with 108 controls with serum samples taken during a similar length of follow up. In addition, a longitudinal study was conducted in 22 cases in which serial serum samples were available before HCC. RESULTS: After adjustment for age, history of cigarette smoking and alcohol consumption, hepatitis B e-antigen positivity, T1653, V1753 and T1762/A1764 double mutations were associated with risk of HCC. Multivariate analysis showed that T1653, V1753 and T1762/A1764 double mutations were independent risk factors of HCC. Moreover, a significant biological gradient of HCC risk by number of mutations in Enh II/BCP regions was observed. Paired samples analysis indicated that the increased HCC risk for at-risk sequence mutations were attributable to the persistence of these mutations, but not a single time point mutation. The longitudinal observation demonstrated a gradual combination of mutations in Enh II/BCP regions accumulated during the development of HCC. CONCLUSION: T1653, V1753 and T1762/A1764 double mutations were independent risk factors of HCC. The effect of combined mutations in Enh II/BCP regions increased the risk and persistence of at-risk sequence mutations and was critical for HCC development.

A case-control study of the relationship between hepatitis B virus DNA level and risk of hepatocellular carcinoma in Qidong, China.

AIM: To investigate the role of hepatitis B virus (HBV) replication in the development of hepatocellular carcinoma (HCC), a nested case-control study was performed to study the relationship between HBV DNA level and risk of HCC. METHODS: One hundred and seventy cases of HCC and 276 control subjects free of HCC and cirrhosis were selected for this study. Serum HBV DNA level was measured using fluorescein quantitative polymerase chain reaction at study entry and the last visit. RESULTS: In a binary unconditional logistic regression analysis adjusted for age, cigarette smoking, alcohol consumption and family history of chronic liver diseases, the adjusted odds ratios (95% confidence intervals) of HCC in patients with increasing HBV DNA level were 2.834 (1.237-6.492), 48.403 (14.392-162.789), 42.252 (14.784-120.750), and 14.819 (6.992-31.411) for HBV DNA levels > or = 10(4) to < 10(5); > or = 10(5) to < 10(6); > or = 10(6) to < 10(7); > or = 10(7) copies/mL, respectively. Forty-six HCC cases were selected to compare the serums viral loads of HBV DNA at study entry with those at the last visit. The HBV DNA levels measured at the two time points did not differ significantly. CONCLUSION: The findings of this study provide strong longitudinal evidence of an increased risk of HCC associated with persistent elevation of serum HBV DNA level in the 10(4)-10(7) range.

Association of hepatitis B virus pre-S deletions with the development of hepatocellular carcinoma in Qidong, China.

BACKGROUND/AIM: To investigate the roles of mutations in pre-S and S regions of hepatitis B virus (HBV) on the progression of hepatocellular carcinoma (HCC) in Qidong, China. METHODS: We conducted an age matched case-control study within a cohort of 2387 male HBV carriers who were recruited from August, 1996. The HBV DNA sequence in pre-S/S regions was successfully determined in 96 HCC cases and 97 control subjects. In addition, a consecutive series of samples from 11 HCC cases were employed to evaluate the pre-S deletion patterns before and after the occurrence of HCC. RESULTS: After adjustment for age, history of cigarette smoking and alcohol consumption, HBeAg positivity, pre-S deletions, pre-S2 start codon mutations, and T53C mutation were significantly associated with HCC, showing adjusted odds ratios (ORs) from 1.914 to 3.199. HCC patients also had a lower frequency of T31C mutation in pre-S2 gene, compared with control subjects (0.524; 95% CI 0.280-0.982). HBV pre-S deletions were clustered mainly in the 5' end of pre-S2 region. Multivariate analysis showed that pre-S deletions and pre-S2 start codon mutations were independent risk factors for HCC. The OR (95% CI) were 2.434 (1.063-5.573) and 3.065 (1.099-8.547), respectively. The longitudinal observation indicated that the pre-S deletion mutations were not acquired at the beginning of HBV infection, but that the mutations occurred during the long course of liver disease. CONCLUSION: Pre-S deletions and pre-S2 start codon mutations were independently associated with the development of HCC. The results also provided direct evidence that pre-S deletion mutations were not acquired from the beginning of infection but arose de novo during the progression of liver disease.

Combined pre-S deletion and core promoter mutations related to hepatocellular carcinoma: A nested case-control study in China.

AIM: To investigate the roles of biomedical factors, hepatitis B virus (HBV) DNA levels, genotypes, and specific viral mutation patterns on the progression of hepatocellular carcinoma (HCC) in Qidong, China. METHODS: A total of 2387 males (aged 20-65 years) who were seropositive for the hepatitis B surface antigen (HBsAg), but had not been diagnosed with HCC, were recruited to a community-based HCC screening study from August, 1996. Evaluation of virological parameters at recruitment was determined for 196 HCC patients during 10 years of follow-up and 323 controls. RESULTS: After adjustment for age at recruitment, history of cigarette smoking and alcohol consumption, alanine aminotransferase (ALT) elevation, alpha-fetoprotein (AFP) levels >20 ng/mL, hepatitis B e antigen positive, HBV DNA levels ≥4.00 log(10) copies/mL, pre-S deletion, T1653 mutation, T1762/A1764 double mutations, and T1766 and/or A1768 mutations were associated with subsequent risk of HCC. A significant biological gradient of HCC risk by HBV DNA levels from less than 2.69 log(10) copies/mL to 6.00 log(10) copies/mL or greater was observed. HBV with a complex mutation combination pattern (pre-S deletion, T1762/A1764 double mutations, and T1766 and/or A1768 mutations) rather than a single mutation was associated with the development of HCC. The longitudinal observation demonstrated a gradual combination of pre-S deletion, T1762/A1764 double mutations, and T1766 and/or A1768 mutations during the development of HCC. CONCLUSIONS: AFP levels >20 ng/mL, high HBV DNA levels, pre-S deletion, and T1762/A1764 double mutations at recruitment were independent risk factors of HCC. Combination of pre-S deletion and core promoter mutations increased the risk of HCC.