Exposure to organochlorine pesticides is independent risk factor of hepatocellular carcinoma: a case--control study.

Primary hepatocellular carcinoma (HCC) is highly prevalent in China. Although hepatitis B virus (HBV) and aflatoxin B1 (AFB1) are considered the major risk factors, among the high-risk cohorts only a small fraction develops liver cancer. Therefore, we investigated if organochlorine pesticides (OCPs) exposure contributed to HCC risk in the Xiamen population. The questionnaire database was built from 346 HCC cases and 961 healthy controls during 2007-2009. The serum levels of α-, β-, γ-, δ-HCH, p, p'-DDT, p, p'-DDE, o, p'-DDT and p, p'-DDD were measured by gas chromatography-tandem mass spectrometer and statistical analysis was done using SPSS16. Significantly, we observed p, p'-DDT, p, p'-DDE, and at first time β-HCH displayed quartile dose-dependent HCC risk trends; p, p'-DDT showed positive (i.e., synergistic) interactions with HBV, diabetes mellitus, AFB1 and polycyclic aromatic hydrocarbon (PAH) exposure, but negative (i.e., antagonistic) interaction with heavy drinking; p, p'-DDE had positive interaction with PAH but negative interaction with HBV and p, p'-DDT; and β-HCH was positively interacted with p, p'-DDT but negatively interacted with heavy drinking and diabetes. p, p'-DDT, p, p'-DDE and β-HCH were independent HCC risk factors. Because of their synergistic interactions with other factors, the high level exposure combined with common AFB1 and HBV exposure in the investigated area may greatly enhance the risk of HCC.