Thyroid tumor marker genomics and proteomics: diagnostic and clinical implications

Two systems biology concepts, genomics and proteomics, are highlighted in this review. These techniques are implemented to optimize the use of thyroid tumor markers (TTM). Tissue microarray studies can produce genetic maps and proteomics, patterns of protein expression of TTM derived from preoperative biopsies and specimens. For instance, papillary and medullary thyroid cancers harbor RAS, RET, and BRAF genetic mutations. Follicular thyroid cancers harbor translocations and fusions of certain genes (PAX 8 and PPAR-gamma). Proteomic analysis from various tissue sources can provide useful information regarding the overall state of a thyroid cancer cell. Understanding the molecular events related to these genetic and protein alterations can potentially clarify thyroid cancer pathogenesis and guide appropriate molecular targeted therapies. However, despite the realization that these emerging technologies hold great promise, there are still significant obstacles to the routine use of TTM. These include equivocal thyroid nodule tissue morphologic interpretations, inadequate standardization of methods, and monetary costs. Interpretative shortcomings are frequently due to the relative scarcity of cellular material from fine-needle aspiration biopsy (FNAB) specimens. This can be rectified with large needle aspiration biopsy (LNAB) techniques and is exemplified by the favorable performance of galectin-3 determinations on LNAB specimens.