Human telomerase reverse transcriptase (hTERT) gene expression in thyroid carcinoma: diagnostic and prognostic role.

BACKGROUND The catalytic component of telomerase, human telomerase reverse transcriptase (hTERT) has been found to be reactivated in immortalized cell lines and considered as a diagnostic marker for malignancy in different body tissues. AIM OF WORK Therefore we thought to determine whether hTERT gene detection could serve as an adjunct in the diagnosis of thyroid lesions together with evaluation of its prognostic value. PATIENTS AND METHODS The study included 50 cases of primary thyroid carcinoma including; 28 papillary carcinoma, 14 follicular carcinoma, 5 anaplastic carcinoma and 3 medullary carcinoma in addition to 5 cases of nodular hyperplasia and 5 cases of follicular adenoma. RNA was extracted from paraffin sections of those patients and hTERT gene expression was identified by Reverse Transcription-Polymerase Chain Reaction (RT-PCR). RESULTS RT-PCR of hTERT gene revealed expression in 43/50 (86%) malignant thyroid cases; including 25 papillary, 11 follicular, 4 anaplastic and 3 medullary carcinoma cases. On the other hand, hTERT gene expression could not be detected in either hyperplastic nodule or in follicular adenoma cases. The diagnostic validity of hTERT gene detection in benign and malignant thyroid lesions was in the form of 88.3% accuracy, 86% sensitivity, 100% specificity, 100% positive predictive value and 90% negative predictive value. No significant association has been found between hTERT gene expression and any clinicopathologic parameters concerned in this study. In thyroid carcinoma cases, hTERT gene detection was the most independent predictor of poor survival by multivariate survival analysis. CONCLUSION Detection of hTERT gene expression should be considered in confirmation of malignant thyroid lesions. Moreover it could be one of the helpful tools in addition to grade, tumor type, and age to stratify patients with thyroid carcinoma into different prognostic categories. Hence, inhibition of hTERT could be of use prospectively in the era of cancer therapy as an attractive weapon in thyroid carcinoma.