Abstract 3026: Dietary intakes and biliary tract cancer risk: Results from cohort studies including 638,860 Chinese and European adults
Authors: Gunchick Valerie , Zheng Wei 
Published: April 2023

Abstract
IntroductionBiliary tract cancer (BTC) is an uncommon, aggressive malignancy with an untreated median overall survival of 2.5-4.5 months for advanced disease. Incidence varies geographically and is generally highest in parts of Asia and South America and lowest in Western countries. Previous dietary risk evaluations have primarily been limited case-control studies with small sample sizes.ObjectiveHere, we prospectively evaluate associations of dietary intakes, BMI, abdominal fat, and physical activity with BTC risk in three cohort studies in two countries, the largest such assessment reported in literature.Methods/Study PopulationWe evaluated 638,816 adults in China and the United Kingdom enrolled in the Shanghai Women’s Health Study (SWHS), Shanghai Men’s Health Study (SMHS), or UK Biobank (UKB). Dietary intake and physical activity information was obtained from study participants at baseline using food frequency and physical activity questionnaires, respectively. All have been validated for these evaluations. Dietary intakes of major food groups were divided into low, middle, and high intake tertiles. BMI was divided by standard cut-offs, and WHR and leisure-time physical activity (measured using MET hours/week) were split into quartiles. Cox regression was used to estimate hazard ratios and 95% confidence intervals for BTC risk in all cohorts. Participants were excluded due to a prior history of cancer, CHD, or stroke at baseline, developing cancer or dying within one year after enrollment, developing cancer after the censor date in UKB, or having extreme energy intakes in SWHS-SMHS.ResultsThe analyzed cohort includes 569,303 participants: 66,944 SWHS, 55,738 SMHS, and 446,621 UKB participants with median enrollment ages of 49, 52, and 57 years old and median follow-up times of 18.1, 12.3, and 11.0 years, respectively. The SWHS observed 206 eligible BTC cases, SMHS 97, and UKB 436. SWHS and SMHS participants were combined for dietary evaluation and the highest tertile of fruit intake showed an inverse association with BTC risk when compared to the lowest tertile: HR (95% CI) 0.65 (0.48-0.89); p-trend 0.008. SWHS-SMHS legume intake was associated with an increased risk: 1.52 (1.13-2.06); p-trend 0.016. In UKB, the highest tertile of fish intake was associated with a reduced risk: opposing tertiles 0.65 (0.49-0.87); p-trend 0.019. A positive relationship between BMI and BTC was observed in all cohorts: pooled analysis 1.66 (1.27, 2.16); p-trend, &lt;0.0001. WHR and BTC were positively associated in pooled analysis: 1.28 (1.01-1.64); p-trend 0.020. Physical activity lacked any association.ConclusionHigh dietary fruit and fish intake might be associated with a reduced risk of BTC. Our study suggests that adiposity and diets may play a role in the etiology of this fatal malignancy.
Citation Format: Valerie Gunchick, Wei Zheng. Dietary intakes and biliary tract cancer risk: Results from cohort studies including 638,860 Chinese and European adults [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3026.