DMMC Course CANCER BIOLOGY TO CANCER MEDICINE

1540-1700 Thursday 25 May 2006.
Durkan Lecture Theatre, Institute of Molecular Medicine, TCD, St James's Hospital

Round Table II: Biomarkers and molecular pathology
Dr Orla Sheils (Institute of Molecular Medicine, St James's Hospital & TCD)

Papillary Thyroid Carcinoma (PTC) is the most common thyroid malignancy, with an incidence of ~22,000 cases in 2004 in the U.S. Incidence is increasing, with a global estimate of half a million new cases this year. PTC is found in a variety of morphological variants, usually grows slowly and is clinically indolent, although rare aggressive forms with local invasion or distant metastases occur. In the recent past, thyroid cancer has been to the forefront of molecular pathology as a result of the consequences of the Chernobyl disaster and the recognition of the role of ret/PTC rearrangements in PTC. Nonetheless, the molecular pathogenesis of this disease remains poorly characterized. In the clinical setting, benign thyroid nodules are far more frequent, and distinguishing between them and malignant nodules is a common diagnostic problem. It is estimated that 5-10% of people will develop a clinically significant thyroid nodule during their lifetime. Although the introduction of fine needle aspiration (FNA) has made identifying PTC more reliable, clinicians often have to make decisions regarding patient care on the basis of equivocal information. Thus the existing diagnostic tools available to distinguish benign from malignant neoplasms are not always reliable. This presentation will evaluate recently described putative biomarkers and evaluate their potential role for diagnostic purposes in FNA cytology samples in the future. It will highlight the evolution of our understanding of the molecular biology of PTC from a narrow focus on specific molecular lesions such as ret/PTC rearrangements to a pan genomic approach.