Endocrine Abstracts

Cell immortalization has been considered for a long time as a classic hallmark of cancer cells. Besides telomere maintenance due to the ‘alternative mechanism of telomere lengthening’ it was advanced that such immortalization could be due to telomerase reactivation, but the mechanisms underlying such reactivation remained elusive.

Mutations in the coding region of telomerase gene are very rare in the cancer setting, despite being associated with some degenerative diseases. Recently, mutations in telomerase (TERT) gene promoter were found in sporadic and familial melanoma and subsequently in several cancer models, notably in gliomas, thyroid cancer and bladder cancer. In thyroid cancer, the relevance of these findings has been reinforced by the association of TERT mutations with tumour aggressiveness, presence of distant metastases and poor patient survival. Specifically, in differentiated thyroid cancers TERT promoter mutations are an indicator of clinically aggressive tumours, being correlated with worse outcome and higher disease-specific mortality. TERT promoter mutations have an independent prognostic value in differentiated thyroid cancer and, notably, in papillary thyroid carcinoma, the most common type of endocrine neoplasia. We will address the role of telomerase genetic alterations in the metastatic profile of thyroid cancer and discuss the value of telomerase as a new biomarker with impact on the prognosis and survival of the patients and as a putative therapeutic target.