To evaluate the role of aflatoxin B1 (AFB1) exposure on risk of hepatocellular carcinoma (HCC), a case-control study nested within a large community based cohort was conducted in Taiwan. Baseline blood (230 HCC cases and 1052 matched controls) and urine samples (198 cases and 904 matched controls) were used to determine by enzyme-linked immunosorbent assays the level of AFB1-albumin adducts and urinary AFB1 metabolites. Conditional logistic regression analysis was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) to assess the effect of AFB1 exposure on risk of HCC. The adjusted-OR for those with urinary AFB1 metabolites levels above the mean compared to those with levels below the mean was 1.76 (95%CI=1.22-2.55). When compared to subjects in the lowest quartile of urinary AFB1 metabolites, there was an increase in risk of HCC, with adjusted ORs (95% CIs) of 0.86 (0.49-1.51), 0.95 (0.55-1.64) and 1.90 (1.16-3.12; Ptrend=0.004) for subjects in the 2nd, 3rd, and 4th quartile, respectively. The corresponding adjusted ORs (95% CIs) were 0.76 (0.27-2.10), 1.10 (0.38-3.20) and 4.11 (1.54-10.97; Ptrend=0.003), respectively, among those noncarriers of hepatitis B Virus (HBV) infection; and 0.90 (0.41-1.99), 0.75 (0.35-1.61) and 1.30 (0.67-2.54; Ptrend=0.39), respectively, for those carriers of chronic HBV infection. The combination of level of both AFB1-albumin adducts and urinary AFB1 metabolites above the mean and chronic HBV infection resulted in an OR of 13.61 (95%CI=5.88-31.53), compared to those with both below the mean and without chronic HBV infection. These data, consistent with our previous study demonstrates that AFB1 exposure is an independent risk factor for HCC risk among those without chronic HBV infection and it also works with HBV in conferring HCC risk.

99th AACR Annual Meeting-- Apr 12-16, 2008; San Diego, CA