Differentiation of follicular thyroid adenoma from carcinoma by means of gene expression profiling with adapter-tagged competitive polymerase chain reaction.
OBJECTIVE
Since preoperative differentiation between follicular thyroid adenoma (FTA) and carcinoma (FTC) remains very difficult, the purpose of this study was to identify the genes differentially expressed in FTA and FTC in order to construct a diagnostic system based on such genes for differentiation of FTA and FTC.


METHODS
Gene expression profiles of 45 FTAs and 22 FTCs were analyzed by means of adapter-tagged competitive polymerase chain reaction (ATAC-PCR) with 2,516 genes (learning set). The genes differentially expressed in FTAs and FTCs were then used to construct a diagnostic system based on the weighted-voting algorithm. In addition, a validation study of this diagnostic system was conducted using 12 FTAs and 6 FTCs (validation set).


RESULTS
The diagnostic system for differentiation of FTA and FTC, constructed with the aid of the learning set samples, was based on 60 genes differentially expressed in FTA and FTC, which included several genes previously identified as overexpressed in FTC (DPP4, KRT19 and IGFBP3) or FTA (trefoil factor 3 and thyroid peroxidase). The leave-one-out cross-validation study showed that the accuracy of this diagnostic system was as high as 90% (sensitivity: 77.3% and specificity: 95.6%), and was confirmed by the validation study (diagnostic accuracy: 83.3%; 95% confidence interval: 62.8-95.4%, sensitivity: 66.7% and specificity: 91.2%).


CONCLUSIONS
This diagnostic system using the ATAC-PCR assay is expected to be clinically useful for preoperative differentiation between FTA and FTC since ATAC-PCR can be used for the small amount of RNA obtained from fine needle aspiration biopsy.
Taniguchi
Kazuya
K
Taisho Laboratory of Functional Genomics, Nara Institute of Science and Technology, Japan.
Takano
Toru
T
Miyauchi
Akira
A
Koizumi
Kyoko
K
Ito
Yasuhiro
Y
Takamura
Yuuki
Y
Ishitobi
Makoto
M
Miyoshi
Yasuo
Y
Taguchi
Tetsuya
T
Tamaki
Yasuhiro
Y
Kato
Kikuya
K
Noguchi
Shinzaburo
S
D000236:Adenoma / Q000175:diagnosis* / Q000235:genetics*; D000465:Algorithms; D016000:Cluster Analysis; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D020407:Internet; D016133:Polymerase Chain Reaction; D012313:RNA / Q000378:metabolism; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013964:Thyroid Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D013997:Time Factors
D012313:RNA