Clinical utility of telomerase for the diagnosis of malignant well-differentiated endocrine tumours.
OBJECTIVE
The distinction between benign and malignant well-differentiated endocrine tumours is hard to achieve. The aim of the present study was to determine whether detection of telomerase or quantification of human telomerase reverse transcriptase protein subunit (hTERT) differ between benign and malignant endocrine tumours.


METHODS
This retrospective study investigated 31 well-differentiated primary endocrine tumours. Based on clinical and histopathological criteria, tumours were categorized with the most recent WHO classification as 'benign' (n = 14), 'uncertain' (n = 5) or 'malignant' (n = 12) with (n = 7) or without (n = 5) metastasis after a mean follow-up of 40.4 +/- 25.8 months (4-122 months). All these tumours were assayed for telomerase activity and hTERT mRNA expression [real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR)].


RESULTS
Telomerase activity was detected in 7 malignant and metastatic tumours, in 1 malignant tumour without metastases, in 1 uncertain tumour and in 1 benign tumour. hTERT mRNA levels were significantly higher in malignant endocrine tumours with or without metastases (P = 0.001) when compared to benign tumours. The negative predictive value of hTERT mRNA quantification for the diagnosis of malignancy was 88.9%, whereas the positive predictive value was 68.7%.


CONCLUSIONS
The presence of telomerase activity within the primary endocrine tumour might indicate a malignant tumour and might suggest the need for an attentive search for concomitant metastases. Quantification of hTERT mRNA could be used in clinical practice to exclude malignancy in most endocrine tumours.
Vezzosi
Delphine
D
Institut National de la Santé et de la Recherche Médicale Unit 531, Institut Louis Bugnard IFR31, Toulouse, France.
Bouisson
Michèle
M
Escourrou
Ghislaine
G
Laurell
Henrik
H
Selves
Jannick
J
Seguin
Philippe
P
Pradayrol
Lucien
L
Caron
Philippe
P
Buscail
Louis
L
D000310:Adrenal Gland Neoplasms / Q000175:diagnosis; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D002276:Carcinoid Tumor / Q000175:diagnosis; D004796:Clinical Enzyme Tests; D004268:DNA-Binding Proteins / Q000032:analysis*; D004701:Endocrine Gland Neoplasms / Q000175:diagnosis*; D005260:Female; D015408:Gastrinoma / Q000175:diagnosis; D005935:Glucagonoma / Q000175:diagnosis; D006801:Humans; D007340:Insulinoma / Q000175:diagnosis; D007414:Intestinal Neoplasms / Q000175:diagnosis; D008175:Lung Neoplasms / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000175:diagnosis; D010673:Pheochromocytoma / Q000175:diagnosis; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019098:Telomerase / Q000032:analysis*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; D016159:Tumor Suppressor Protein p53; D019098:Telomerase