Activation of telomerase and its diagnostic application in biopsy specimens from biliary tract neoplasms

BACKGROUND. Telomerase activity has been reported to have potential as a us eful diagnostic marker for cancer in various organs. The authors previously reported that telomerase activity in pancreatic juice differentiates pancr eatic ductal carcinoma from adenoma and pancreatitis. In the current study, the usefulness of semiquantitatively determined telomerase activity in the diagnosis of malignant biliary tract neoplasms was investigated. METHODS, The samples examined included 61 surgically resected biliary tract tissues (11 gallbladder carcinomas, 5 bile duct carcinomas, 1 gallbladder adenoma, 30 cholecytitis cases, 7 cholesterol polyps, 1 normal gallbladder, and 6 normal common bile duct tissues), 42 bile samples from patients with biliary tract or pancreatic disease (19 cases of malignant biliary tract d isease, 11 cases of benign biliary tract disease, 10 cases of malignant pan creatic disease, and 2 cases of benign pancreatic disease), and 14 bile duc t biopsy specimens collected by percutaneous transhepatic choledochoscopy o r endoscopic retrograde cholangiopancreatography (8 bile duct carcinoma spe cimens, 1 bile duct adenoma specimen, and 5 hepatolithiasis specimens). RESULTS. In biliary tract tissues, a telomerase ladder was detected in 73% of gallbladder carcinomas, 40% of bile duct carcinomas, and none of the oth er biliary tract tissues. One gallbladder adenoma shelved a weak telomerase ladder. The telomerase ladder was detected in the bile sample from 1 patie nt (5.3%) with malignant biliary tract disease, none of the patients with b enign biliary tract disease, 5 patients (50%) with malignant pancreatic dis ease, and none of the patients with benign pancreatic disease. In biopsy sp ecimens, the telomerase ladder was detected in 75% of patients with bile du ct carcinoma but not in any of the patients with hepatolithiasis. The media n value of relative telomerase activity in the patients with bile duct carc inoma was significantly higher than that in the patients with hepatolithias is. The diagnosis of bile duct carcinoma was confirmed preoperatively by hi stopathologic examination in only 25% of the biopsy specimens. CONCLUSIONS, The results of the current study indicate that telomerase is h ighly activated in biliary tract carcinomas and that the detection of a tel omerase ladder in biopsy samples is an excellent tool for the diagnosis of bile duct carcinomas. Cancer 1999;85:2138-43. (C) 1999 American Cancer Soci ety.