Aflatoxin B₁ exposure increases the risk of cirrhosis and hepatocellular carcinoma in chronic hepatitis B virus carriers

The relation between aflatoxin B₁ (AFB₁) and cirrhosis in chronic carriers of hepatitis B virus (HBV) remains inconclusive. This case-control study nested in a large community-based cohort aimed to assess the effect of AFB₁ exposure on cirrhosis and HCC in chronic HBV carriers. Serum AFB₁-albumin adduct levels at study entry were measured in 232 cirrhosis cases, 262 HCC cases and 577 controls. Multivariate-adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs) were estimated using logistic regression. Among all chronic HBV carriers, the time intervals between study entry and diagnosis of HCC, cirrhosis, cirrhotic HCC, and non-cirrhotic HCC were all significantly (p < 0.0001) shorter in participants with high serum levels of AFB₁-albumin adducts than those with low/undetectable levels. There were significant dose-response relations with serum AFB₁-albumin adduct level at study entry for cirrhosis (p-trend = 0.0001) and cirrhotic HCC (p-trend < 0.0001) newly diagnosed within 9 years after entry as well as non-cirrhotic HCC (p-trend = 0.021) newly diagnosed within 4 years after entry. The aORs (95% CIs) for high versus undetectable serum AFB₁-albumin adduct levels were 2.45 (1.51–3.98) for cirrhosis (p = 0.0003), 5.47 (2.20–13.63) for cirrhotic HCC (p = 0.0003), and 5.39 (1.11–26.18) for non-cirrhotic (p = 0.0368) HCC, respectively. There remained a significant dose-response relation between serum AFB₁-albumin adduct level and HCC risk (p-trend = 0.0291) in cirrhosis patients, showing an aOR (95% CI) of 3.04 (1.11–8.30) for high versus undetectable serum levels (p = 0.0299). It is concluded that AFB₁ exposure may increase the risk of cirrhosis and HCC in a dose-response manner among chronic HBV carriers.