spectively, P ยฐ.0001 for each comparison), even after To evaluate the a priori hypotheses that an increased excluding those with a serum bilirubin higher than 2.0 level of glyco and tauro lithocholic acid, perhaps bemg/dL. Bile cholesterol was lower for the cases as well cause of a decreased capacity for hepatic sulfation, con-(median 1.70 mmol/mL vs. 4.90 mmol/mL and 16.81 mmol/ tributed to the biochemical epidemiology of gallbladder mL, respectively, P ยฐ.02), as was the concentration of cancer, a case-control study was undertaken at four hosbile phospholipids (median 2.97 mmol/mL vs. 6.26 mmol/ pitals in La Paz, Bolivia, and at one hospital in Mexico mL and 52.69 mmol/mL, P ร
.1 and .0004, respectively). City, Mexico. Eighty-four cases with newly diagnosed Contrary to our a priori hypothesis, there was no differhistologically confirmed gallbladder cancer were comence between the cases and either control group in their pared with 264 controls with cholelithiasis or choledobile concentrations of lithocholate, the proportion of bile cholithiasis in the absence of cancer and with 126 conacids which were sulfated, or the concentration of nontrols with normal biliary tracts. All study subjects were sulfated lithocholate. However, the cases had a higher undergoing abdominal surgery. Interview data were colconcentration of ursodeoxycholate (UDC) (P รต .004 for lected for all study subjects, as well as blood, bile, and both control groups), especially glycoursodeoxycholate gallstone specimens when feasible. Sera were analyzed (P รต .001 for both control groups). A previously pubfor carcinoembryonic antigen, cholesterol concentralished suggestion that gallstone size differed between tion, and total bile acids. Bile specimens were analyzed cases and controls was not confirmed. In conclusion, for carcinoembryonic antigen; and for concentration of cases with gallbladder cancer differed from controls bile salts; cholesterol; phospholipids; and the glycine with stones and from controls with normal biliary tracts and taurine conjugates of cholic, ursodeoxycholic, chein their serum and bile biochemistries. These findings nodeoxycholic, deoxycholic, and lithocholates; sulfoglymay be a reflection of the disease process, or may procolithocholate; and sulfotaurolithocholate. Gallstone vide useful clues to its pathogenesis. (HEPATOLOGY specimens were analyzed for the percentage of choles-1996;23:1402-1411.) terol content, the percentage of calcium bilirubinate content, and the percentage of calcium carbonate content. Serum bile acids were increased in cases versus
The study of gallbladder cancer provides a unique the two control groups (median 11.7 nmol/mL vs. 9.3 opportunity to combine biochemistry and epidemiology nmol/mL for stone controls and 8.2 nmol/L for nonstone to investigate the possible cause of cancers that are controls, P ยฐ.02 for each pairwise comparison). Biliary uncommon in the United States' black and white popubile acids were markedly decreased in the cases (median 3.98 mmol/mL vs. 33.09 mmol/mL and 154.0 mmol/L, re-lations, but of considerable international importance among Hispanic, and especially Amerind, populations. 1 Different parts of the biliary tract are bathed in the Abbreviations: HDL, high-density lipoprotein; HPLC, high-pressure liquid same material: bile. Yet, there are important differchromatography; TUDC, taurousodeoxycholate; GUDC, glycoursodeoxychoences in the epidemiology of cancers of the liver, the late; GC, glycocholate; TCDC, taurochenodeoxycholate; GCDC, glycochenointrahepatic bile ducts, the extrahepatic bile ducts, the deoxycholate; CDC, chenodeoxycholate; DC, deoxycholate; UDC, ursodeoxycholate; UDCA, ursodeoxycholic acid. ampulla of Vater, and the gallbladder. 2 In addition, From