Well-differentiated thyroid carcinomas (WDTC) comprise two well-defined histological types: papillary and follicular thyroid carcinomas (PTC and FTC, respectively). These two types of tumour despite being derived from the same cell of origin, the thyroid follicular cell, accumulate distinct genetic abnormalities during tumour progression.
Molecular pathology of thyroid cancer is now better understood due to the identification of RET/PTC rearrangements and BRAF mutations in the ethiopathogenesis of the large majority of PTC, and the high prevalence of RAS mutations and PAX8/PPARγ rearrangements in follicular patterned carcinomas (FTC and follicular variant of PTC).
In this review we summarize most of the molecular alterations that are currently used as targets for the new biological treatments and anticipate some of the changes that are already occurring or will occur in the therapy of patients with thyroid cancer. For the sake of simplicity we decided to divide the paper according to the major genetic alterations identified in WDTC (RET/PTC rearrangements, BRAF mutations, RAS mutations and mitochondrial DNA deletions and mutations) and their respective therapeutics.