In situ hybridization for telomerase RNA in routine cytologic brushings for the diagnosis of pancreaticobiliary malignancies

Background: Brush cytology for the diagnosis of pancreaticobiliary malignancy has an overall sensitivity of 50%. Accurate and specific markers are therefore needed for the optimal evaluation of pancreaticobiliary strictures. Telomerase activity is present in 85% to 90% of all human cancers. We sought to determine the utility of in situ hybridization for telomerase RNA in endoscopic brushings for the diagnosis of pancreaticobiliary malignancy. Methods: Endoscopic brushings from 18 patients with pancreatic or biliary strictures were evaluated by routine cytology and in situ hybridization for telomerase RNA. Results: Eight of 18 strictures were malignant. Cytology was positive in 5 patients, whereas telomerase RNA was positive in 6. All malignancies were diagnosed by either cytology or telomerase RNA; however, both studies were positive in only 3. There were no false-positive results by either technique. Conclusion: The detection of telomerase RNA in endoscopic brushings may be an important adjunct to cytology for cancer diagnosis in pancreaticobiliary strictures.