Aflatoxin serum levels and risk of hepatoeellular carcinoma in a nested case-control study in the United States

摘要

Background Aflatoxin is one of the most powerful chemical carcinogens known. While it is well known that ingestion or exposure to high levels of aflatoxin is associated with a greater risk of hepatocellular carcinoma (HCC), particularly among chronic HBV carriers, no studies have examined this association in a low exposure region with exposure measured prospectively. Aims To address this gap, we conducted a nested case-control study within the Multiphasic Health Check-up (MHC) cohort at Kaiser Permanente Northern California (KPNC). Methods The study population was defined as the MHC participants who provided a serum sample between 1964 and 1985 with serum available. HCC cases (n=193) that occurred after MHC exam date were identified by linkage to the KPNC Cancer Registry. Controls (n=578) were randomly selected and matched to cases on age, sex, race/ethnicity and date of MHC exam (serum draw). Serum aflatoxin-albumin (AF-alb) adduct levels were determined by an enzyme-linked immunosorbent assay (EUSA) after albumin extraction, digestion and purification with the limit of detection at 0.5 pg AF-lysine equivalent per mg albumin. Results 118 participants had levels of AF-alb above the detection limit (16.1% of the cases and 15.1% of the controls). Among individuals with detectable levels, the range of AF-alb levels was 0.70 to 138.00 pg/mg. The majority of detectable levels were near the limits of detection, where the assay is least precise. Only a single case (0.5%) and 12 controls (2%) had levels ＞10.00 pg/mg. In a conditional logistic regression model, the odds ratio for having a detectable serum AF-alb level in relation to risk of HCC was 1.19 (95% confidence interval 0.76-1.87). Conclusions This study provides no evidence that low exposure levels of aflatoxin found in this U.S. sample are associated with.