Classification of follicular XXXX by molecular signature: results of gene profiling.

@entity5 @entity189 @entity6888 @entity652 @entity259
PURPOSE: Thyroid nodules are common, with a lifetime risk of developing a clinically significant thyroid nodule of 10% or higher. Preoperative diagnosis was greatly enhanced by the introduction of fine needle aspiration in the 1970s, but there has been little advancement since that time. Discrimination between benign and @entity5 is currently not possible by fine needle aspiration and can even be difficult after full pathologic review. The purpose of these studies is to identify genes expressed in follicular @entity652 and @entity189 of the thyroid that will permit molecular differentiation of these @entity5 . EXPERIMENTAL DESIGN: Gene expression patterns of 17 @entity6888 were analyzed by oligonucleotide array analysis. Gene profiles for follicular @entity652 and @entity189 were identified, and the two groups were compared for differences in expression levels. The differentially expressed genes were used to perform a hierarchical clustering analysis training set. Five @entity5 with diagnosis undisclosed to the investigators and 2 minimally invasive @entity189 were entered into the cluster analysis as a test set to determine whether diagnosis by gene profile correlated with that obtained by pathologic evaluation. RESULTS: @entity259 and @entity189 showed strikingly distinct gene expression patterns. The expression patterns of 105 genes were found to be significantly different between follicular @entity652 and @entity189 . Many uncharacterized genes contributed to the distinction between @entity5 types. For five @entity5 for which the final diagnosis was undisclosed, the clustering algorithm gave the correct diagnosis in all 5 cases. CONCLUSIONS: Gene profiling is a useful tool to predict the molecular diagnosis of follicular @entity259 . Genes were identified that reliably differentiate @entity259 from @entity652 . This study provides insight into genes that may be important in the molecular pathogenesis of follicular @entity259 , as well candidates for preoperative diagnosis of @entity259 .
