Tea drinking and the risk of biliary tract cancers and biliary stones: A population-based case–control study in Shanghai, China
Article first published online: 4 JAN 2006
Copyright © 2006 Wiley-Liss, Inc.
International Journal of Cancer
Volume 118, Issue 12, pages 3089–3094, 15 June 2006
How to Cite
Zhang, X.-H., Andreotti, G., Gao, Y.-T., Deng, J., Liu, E., Rashid, A., Wu, K., Sun, L., Sakoda, L. C., Cheng, J.-R., Shen, M.-C., Wang, B.-S., Han, T.-Q., Zhang, B.-H., Gridley, G., Fraumeni, J. F. and Hsing, A. W. (2006), Tea drinking and the risk of biliary tract cancers and biliary stones: A population-based case–control study in Shanghai, China. Int. J. Cancer, 118: 3089–3094. doi: 10.1002/ijc.21748
- Issue published online: 27 MAR 2006
- Article first published online: 4 JAN 2006
- Manuscript Accepted: 26 OCT 2005
- Manuscript Received: 24 JUN 2005
- Intramural Research Program of the National Institutes of Health (NCI)
- biliary tract cancers;
- tea consumption;
Biliary tract cancers, encompassing tumors of the gallbladder, extrahepatic bile ducts and ampulla of Vater, are rare but highly fatal malignancies. Apart from gallstones, etiologic factors for biliary tract cancer are not clearly defined. Several epidemiologic studies have suggested that consumption of tea, especially green tea, is protective against a variety of cancers, including gastrointestinal malignancies. As part of a large population-based case–control study of biliary tract disease in Shanghai, China, we evaluated the effects of tea consumption on the risk of biliary tract cancers and biliary stones. The study included 627 incident cases with biliary tract cancer, 1,037 cases with biliary stones and 959 randomly selected controls. Study subjects were interviewed to ascertain data on demographic, medical and dietary factors, including tea consumption. Forty-one percent of the controls were ever tea drinkers, defined as those who consumed at least 1 cup of tea per day for at least 6 months. After adjustment for age, education and body mass index, among women, ever tea drinkers had significantly reduced risks of biliary stones (OR = 0.73, 95% CI = 0.54–0.98) and gallbladder cancer (OR = 0.56, 95% CI = 0.38–0.83). The inverse relationship between tea consumption and gallbladder cancer risk was independent of gallstone disease. Among men, tea drinkers were more likely to be cigarette smokers, and the risk estimates were generally below 1.0, but were not statistically significant. Further studies are needed to confirm these results in other populations and clarify the hormonal and other mechanisms that may be involved. © 2006 Wiley-Liss, Inc.