Quantitative evaluation of hepatitis B virus mutations and hepatocellular carcinoma risk： a meta-analysis of prospective studies

Background： The temporal relationship between hepatitis B virus （HBV） mutations and hepatocellular carcinoma （HCC） remains unclear. Methods： We conducted a meta-analysis including cohort and nested case-control studies to prospectively examine the HCC risk associated with common variants of HBV in the PreS, Enhancer Ⅱ, basal core promoter （BCP） and precore regions. Pertinent studies were identified by searching PubMed, Web of Science and the Chinese Biological Medicine databases through to November 2014. Study-specific risk estimates were combined using fixed or random effects models depending on whether significant heterogeneity was detected. Results： Twenty prospective studies were identified, which included 8 cohort and 12 nested case-control studies. There was an increased risk of HCC associated with any PreS mutations with a pooled relative risk （RR） of 3.82 [95% confidence interval （CI）： 2.59-5.61]. The pooled-RR for PreS deletion was 3.98 （95% CI： 2.28-6.95）, which was higher than that of PreS2 start codon mutation （pooled-RR=2.63, 95% CI： 1.30-5.34）. C1653T in Enhancer Ⅱ was significantly associated with HCC risk （pooled-RR=l.83; 95% CI： 1.21-2.76）. For mutations in BCP, statistically significant pooled-RRs of HCC were obtained for T1753V （pooled- RR=2.09; 95% CI： 1.49-2.94） and AI762T/G1764A double mutations （pooled-RR=3.11; 95% CI： 2.08- 4.64）. No statistically significant association with HCC risk was observed for G1896A in the precore region （pooled-RR=0.77; 95% CI： 0.47-1.26）. Conclusions： This study demonstrated that PreS mutations, C1653T, T1753V, and A1762T/G1764A, were associated with an increased risk of HCC. Clinical practices concerning the HCC risk prediction and diagnosis may wish to focus on patients with these mutations.