Detection of telomerase activity in biopsy specimens for diagnosis of biliary tract cancers.
BACKGROUND
Telomerase activity is detectable in more than 85% of primary cancers. We determined telomerase activity in biopsy specimens obtained from biliary tract cancers to evaluate the clinical application of telomerase activity detection in combination with p53 immunostaining and routine histologic examination.


METHODS
Biopsy specimens obtained during percutaneous transhepatic cholangioscopy from 13 patients with cholangiocarcinoma, 3 patients with gallbladder carcinoma, and 4 patients with intrahepatic bile duct stones were evaluated by routine histologic examination, p53 immunostaining, and telomerase activity. Semiquantitative determination of telomerase activity was performed using a fluorescence-based telomeric repeat amplification protocol.


RESULTS
Thirteen of 16 specimens of malignant tissue had detectable telomerase activity, whereas no specimen of nonmalignant tissue had detectable telomerase activity. A p53 overexpression was recognized by immunostaining in 9 of 16 samples with cancers. Combining both telomerase activity and p53 overexpression resulted in the detection of all cancer with a sensitivity of 100%. There were no false-positive results by either modality (specificity 100%).


CONCLUSIONS
The detection of telomerase activity in biopsy specimens and p53 overexpression in combination with routine histologic examination may improve the diagnosis of biliary tract cancers. (Gastrointest Endosc 2000;52:380-6).
Itoi
T
T
Fourth Department of Internal Medicine, Tokyo Medical University, Tokyo, Japan. itoi@tokyo-med.ac.jp
Shinohara
Y
Y
Takeda
K
K
Takei
K
K
Ohno
H
H
Ohyashiki
K
K
Yahata
N
N
Ebihara
Y
Y
Saito
T
T
D000368:Aged; D000369:Aged, 80 and over; D000912:Antibodies, Neoplasm / Q000032:analysis; D001650:Bile Duct Neoplasms / Q000201:enzymology* / Q000473:pathology; D001653:Bile Ducts, Intrahepatic / Q000201:enzymology* / Q000473:pathology; D014408:Biomarkers, Tumor; D001706:Biopsy / Q000379:methods; D018281:Cholangiocarcinoma / Q000201:enzymology* / Q000473:pathology; D017931:DNA Primers / Q000737:chemistry; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D003937:Diagnosis, Differential; D016145:Endoscopy, Digestive System; D005260:Female; D006801:Humans; D015151:Immunoblotting; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D019098:Telomerase / Q000235:genetics / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000276:immunology / Q000378:metabolism
D000912:Antibodies, Neoplasm; D014408:Biomarkers, Tumor; D017931:DNA Primers; D004273:DNA, Neoplasm; D016159:Tumor Suppressor Protein p53; D019098:Telomerase