title: Strategies for chemoprevention of liver cancer.
abstract: Liver cancer is one of the most common cancers worldwide. Infection with hepatitis B virus and exposure to aflatoxins in the diet act synergistically to amplify risk. From a public health perspective, hepatitis virus vaccination programs and efforts to both reduce aflatoxin exposures and to attenuate the toxicological consequences of unavoidable exposures should have major impacts on the incidence of this disease. Experimentally, aflatoxin-induced hepatocarcinogenesis can be inhibited by over a score of different chemopreventive agents with multiple mechanisms of action. One agent, oltipraz, is a potent inducer of phase 2 enzymes involved in the detoxication of carcinogens including aflatoxin. A second agent, chlorophyllin, impedes the bioavailability of carcinogens by forming molecular complexes and enhances their elimination in the fecal stream. This review highlights the findings of recent randomized clinical trials with oltipraz and chlorophyllin conducted in individuals exposed to dietary aflatoxins and at high risk for development of liver cancer. Both chemopreventive agents modulated levels of aflatoxin biomarkers in the study participants in manners consonant with protection.
authors.affiliation: Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA. tkensler@jhsph.edu
authors.forename: Thomas W
authors.initials: TW
authors.lastname: Kensler
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Egner
authors.forename: Jin-Bing
authors.initials: JB
authors.lastname: Wang
authors.forename: Yuan-Rong
authors.initials: YR
authors.lastname: Zhu
authors.forename: Bao-Chu
authors.initials: BC
authors.lastname: Zhang
authors.forename: Geng-Sun
authors.initials: GS
authors.lastname: Qian
authors.forename: Shuang-Yuan
authors.initials: SY
authors.lastname: Kuang
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Gange
authors.forename: Lisa P
authors.initials: LP
authors.lastname: Jacobson
authors.forename: Alvaro
authors.initials: A
authors.lastname: Muñoz
authors.forename: John D
authors.initials: JD
authors.lastname: Groopman
mesh_terms: D016588:Anticarcinogenic Agents / Q000008:administration & dosage*; D006528:Carcinoma, Hepatocellular / Q000517:prevention & control*; D018890:Chemoprevention / Q000379:methods*; D002735:Chlorophyllides / Q000008:administration & dosage*; D002986:Clinical Trials as Topic; D005260:Female; D005544:Forecasting; D006801:Humans; D008113:Liver Neoplasms / Q000517:prevention & control*; D008297:Male; D011322:Primary Prevention / Q000592:standards / Q000639:trends; D011379:Prognosis; D011719:Pyrazines / Q000008:administration & dosage*; D018570:Risk Assessment; D013871:Thiones; D013876:Thiophenes
chemical_list: D016588:Anticarcinogenic Agents; D002735:Chlorophyllides; D011719:Pyrazines; D013871:Thiones; D013876:Thiophenes; C026209:oltipraz; C007020:chlorophyllin