title: Bile acid analysis in biliary tract cancer.
abstract: The etiology of biliary tract cancer is obscure, but there are evidences that bile acid plays a role in carcinogenesis. To find the association between biliary tract cancer and bile acid, this study compared the bile acid concentration and composition among patients with biliary cancer, biliary tract stones, and no biliary disease. Bile was compared among patients with biliary tract cancer (n = 26), biliary tract stones (n = 29), and disease free controls (n = 9). Samples were obtained by percutaneous transhepatic biliary drainage, endoscopic nasobiliary drainage, or gallbladder puncture, and analyzed for cholic, deoxycholic, chenodeoxycholic, lithocholic, and ursodeoxycholic acid composition. Total bile acid concentration was lower in the cancer group than the biliary stone and control groups; the proportions of deoxycholic (2.2% vs. 10.2% and 23.6%, p < 0.001 and p < 0.001, respectively) and lithocholic acid (0.3% vs. 0.6% and 1.0%, p = 0.065 and p < 0.001, respectively) were also lower. This result was similar when disease site was limited to bile duct or gallbladder. Analysis of cases with bilirubin <or= 2.0 mg/dL also showed lower total bile acid concentration and deoxycholic acid composition in the cancer group compared to controls (5.7% vs. 23.6%, p = 0.003). Although the presence of bile duct obstruction explains some of the difference in total concentration and composition of bile acid, there are other contributing mechanisms. We suspect the alteration of bile acid transport might decrease bile acid excretion and cause the accumulation of carcinogenic bile acid in bile duct epithelium.
authors.affiliation: Division of Gastroenterology, Institute of Gastroenterology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jeong Youp
authors.initials: JY
authors.lastname: Park
authors.forename: Byung Kyu
authors.initials: BK
authors.lastname: Park
authors.forename: Jun Sang
authors.initials: JS
authors.lastname: Ko
authors.forename: Seungmin
authors.initials: S
authors.lastname: Bang
authors.forename: Si Young
authors.initials: SY
authors.lastname: Song
authors.forename: Jae Bock
authors.initials: JB
authors.lastname: Chung
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001661:Biliary Tract Neoplasms / Q000737:chemistry* / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000032:analysis; D002769:Cholelithiasis / Q000378:metabolism; D002793:Cholic Acids / Q000032:analysis* / Q000378:metabolism; D005260:Female; D005706:Gallbladder Neoplasms / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged
chemical_list: D014408:Biomarkers, Tumor; D002793:Cholic Acids