Association of tea and coffee consumption and biliary tract cancer risk: The Biliary Tract Cancers Pooling Project

Background and Aims: Tea and coffee are widely consumed beverages worldwide. We evaluated their association with biliary tract cancer (BTC) incidence. Approach and Results: We pooled data from 15 studies in the Biliary Tract Cancers Pooling Project to evaluate associations between tea and coffee consumption and biliary tract cancer development. We categorized participants as nondrinkers (0 cup/day), moderate drinkers (>0 and <3 cups/day), and heavy drinkers (≥3 cups/day). We estimated multivariable HRs and 95% CIs using Cox models. During 29,911,744 person-years of follow-up, 851 gallbladder, 588 intrahepatic bile duct, 753 extrahepatic bile duct, and 458 ampulla of Vater cancer cases were diagnosed. Individuals who drank tea showed a statistically significantly lower incidence rate of gallbladder cancer (GBC) relative to tea nondrinkers (HR=0.77; 95% CI, 0.64-0.91), and intrahepatic bile duct cancer (IHBDC) had an inverse association (HR=0.81; 95% CI, 0.66-1.00). However, no associations were observed for extrahepatic bile duct cancer (EHBDC) or ampulla of Vater cancer (AVC). In contrast, coffee consumption was positively associated with GBC, with a higher incidence rate for individuals consuming more coffee (HR^{<3 cups/day}=1.29; 95% CI, 1.01-1.66; HR^{≥3 cups/day}=1.49; 95% CI, 1.11-1.99, P^trend =0.01) relative to coffee nondrinkers. However, there was no association between coffee consumption and GBC when restricted to coffee drinkers. There was little evidence of associations between coffee consumption and other biliary tract cancers. Conclusions: Tea consumption was associated with a lower incidence of GBC and possibly IHBDC. Further research is warranted to replicate the observed positive association between coffee and GBC.