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Trends in biliary tract cancer incidence rates have increased in Shanghai, China. These trends have coincided with economic and developmental growth, as well as a shift in dietary patterns to a more Westernized diet. To examine the effect of dietary changes on incident disease, we evaluated associations between diet and biliary tract cancers amongst men and women from a population-based case-control study in Shanghai, China. Biliary tract cancer cases were recruited from 42 collaborating hospitals in urban Shanghai, and population-based controls were randomly selected from the Shanghai Household Registry. Food frequency questionnaire data were available for 225 gallbladder, 190 extrahepatic bile duct, and 68 ampulla of Vater cancer cases. A total of 39 food groups were created and examined for associations with biliary tract cancer. Interestingly, only four food groups demonstrated a suggested association with gallbladder, extrahepatic bile duct, or ampulla of Vater cancers. The allium food group, consisting of onions, garlic, and shallots showed an inverse association with gallbladder cancer (OR: 0.81, 95% CI: 0.68–0.97). Similar trends were seen in the food group containing seaweed and kelp (OR: 0.79, 95% CI: 0.67–0.96). In contrast, both preserved vegetables and salted meats food groups showed positive associations with gallbladder cancer (OR:1.27, 95% CI: 1.06–1.52; OR: 1.18, 95% CI: 1.02–1.37, respectively). Each of these four food groups showed similar trends for extrahepatic bile duct and ampulla of Vater cancers. The results of our analysis suggest intake of foods with greater anti-inflammatory properties may play a role in decreasing the risk of biliary tract cancers. Future studies should be done to better understand effects of cultural changes on diet, and to further examine the impact diet and inflammation have on biliary tract cancer incidence. [ABSTRACT FROM AUTHOR]

Background & Aims Aflatoxin, which causes hepatocellular carcinoma, may also cause gallbladder cancer. We investigated whether patients with gallbladder cancer have higher exposure to aflatoxin than patients with gallstones. Methods We measured aflatoxin B 1 (AFB 1 )–lysine adducts in plasma samples from the Shanghai Biliary Tract Cancer case-control study, conducted from 1997 through 2001. We calculated age- and sex-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) and the population-attributable fraction for 209 patients with gallbladder cancer and gallstones vs 250 patients with gallstones without cancer (controls). In 54 patients with gallbladder cancer, tumor tissue was examined for the R249S mutation in TP53 , associated with aflatoxin exposure, through targeted sequencing. Results The AFB 1 –lysine adduct was detected in 67 (32%) of 209 patients with gallbladder cancer and 37 (15%) of the 250 controls (χ 2 P < .0001), almost threefold more patients with gallbladder cancer than controls (OR, 2.71; 95% CI, 1.70–4.33). Among participants with detectable levels of AFB 1 –lysine, the median level of AFB 1 –lysine was 5.4 pg/mg in those with gallbladder cancer, compared with 1.2 pg/mg in controls. For patients in the fourth quartile of AFB 1 –lysine level vs the first quartile, the OR for gallbladder cancer was 7.61 (95% CI, 2.01–28.84). None of the 54 gallbladder tumors sequenced were found to have the R249S mutation in TP53 . The population-attributable fraction for cancer related to aflatoxin was 20% (95% CI, 15%–25%). Conclusions In a case-control study of patients with gallbladder cancer and gallstones vs patients with gallstones without cancer, we associated exposure to aflatoxin (based on plasma level of AFB 1 –lysine) with gallbladder cancer. Gallbladder cancer does not appear associate with the R249S mutation in TP53 . If aflatoxin is a cause of gallbladder cancer, it may have accounted for up to 20% of the gallbladder cancers in Shanghai, China, during the study period, and could account for an even higher proportion in high-risk areas. If our findings are verified, reducing aflatoxin exposure might reduce the incidence of gallbladder cancer. [ABSTRACT FROM AUTHOR]