Abstract CN05-01: Viral and Dietary Factors in Declining Liver Cancer Mortality in Qidong, China

Abstract

Abstract Liver cancer is the third leading cause of cancer mortality globally. In endemic areas of sub-Saharan Africa and southeast Asia liver cancer largely arises from both chronic infection with hepatitis B virus (HBV) and the ingestion of aflatoxin-contaminated foods such as corn and groundnuts. While synergistic interactions between these viral and chemical carcinogens have been observed in prospective cohort studies in China, the effects of primary prevention against both of these factors has not been examined. Mortality rates from liver cancer by birth cohort in Qidong, China were compared to timelines in the region for the introduction of HBV vaccination and to mandated, wholesale changes in staple foodstuffs from corn to rice. Levels of aflatoxin-albumin adducts in archived serum samples collected in Qidong from 1989 to 2012 were quantified by isotope dilution mass spectrometry as measures of carcinogen exposure. Halving of mortality rates from liver cancer are seen between birth cohorts from the 1960s and 1980s for residents 34 years old and younger. However, prevalence of HBsAg positivity was unchanged in these cohorts as all were born prior to implementation of universal HBV vaccination of newborns. Changing agricultural policies from a planned to a market-oriented economy in the early 1980s led from corn to rice based diets and dramatic decreases in aflatoxin exposures in Qidong. Substantial declines in liver cancer morality in birth cohorts occurring prior to the introduction of a universal HBV vaccination program in Qidong highlight the importance of altered food policies as a means for rapid risk reduction, especially amongst the ∼350 million HBV carriers, many of whom reside in endemic areas. Supported by NIEHS ES 006052 and National Science and Technology of China 2008ZX10002-015. Citation Format: Thomas W. Kensler. Viral and dietary factors in declining liver cancer mortality in Qidong, China. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr CN05-01.