ABSTRACT
BACKGROUND: The prognosis for thyroid cancer differs between metastatic and non-metastatic cases. To identify biomarkers useful for thyroid cancer diagnosis and to establish a marker panel for the early detection of metastatic thyroid carcinoma, this study compared histomorphological features and biomarker expression profiles in thyroid carcinomas according to pathological diagnoses. PATIENTS AND METHODS: Thyroid carcinoma samples were obtained from 113 consecutive patients who underwent resection at multiple centers between 2001 and 2008. These cases included 63 metastatic thyroid tumors (34 papillary carcinomas, 20 follicular carcinomas, 9 undifferentiated carcinomas) and 50 non-metastatic thyroid tumors (36 papillary carcinomas, 14 follicular carcinomas). Tissue microarrays constructed using the 113 samples were analyzed by immunohistochemistry for the expression of 16 protein markers: MMP9, VEGF-C, E-cadherin, MMP2, PPARγ, PCNA, CXCR4, PTEN, C-myc, PTTG, HBME-1, p16, p53, FHIT, bFGF and hTERT. The clinicopathological variables with diagnostic significance were determined by multivariate analysis, and the predictive values of the identified biomarkers for metastasis in thyroid carcinoma were determined by receiver operating characteristic (ROC) curve analysis. RESULTS: The expression of six proteins, VEGF-C, MMP2, CXCR4, PTTG, HBME-1 and bFGF, was up-regulated in metastatic compared to non-metastatic thyroid carcinoma. Multiple factor binary ordinal logistic regression analysis showed that MMP2, PTTG, VEGF-C, CXCR4 and bFGF were independent factors associated with the metastatic status of thyroid carcinoma. ROC curve analysis of these five proteins revealed that VEGF-C and bFGF were the most useful protein markers for the diagnosis of metastatic thyroid cancer. CONCLUSION: MMP2, PTTG, VEGF-C, CXCR4 and bFGF are potential cellular tumor markers for identifying thyroid cancer with greater risk for metastasis and the novel combination of VEGF-C and bFGF as biomarkers may improve the accuracy of early detection and the differential diagnosis between metastatic and non-metastatic thyroid carcinoma.
Subject(s)
Biomarkers, Tumor/metabolism , Thyroid Neoplasms/diagnosis , Thyroid Neoplasms/metabolism , Humans , Immunohistochemistry , Logistic Models , Neoplasm Metastasis , Neoplasm Proteins/metabolism , Predictive Value of Tests , Thyroid Neoplasms/pathologyABSTRACT
Early diagnosis and treatment of thyroid cancers are critical for better prognosis and better survival rates. The purpose of this study was to identify potential diagnostic markers for papillary thyroid carcinomas with distant metastasis. Fifty-eight papillary thyroid tumor specimens (27 papillary thyroid carcinomas with distant metastasis and 31 without metastasis) were examined, and protein expression of pituitary tumor-transforming gene (PTTG), E-cadherin, p27kip1, vascular endothelial growth factor (VEGF)-C, metalloproteinase (MMP) 2, MMP9, chemokine receptor CXCR4, and basic fibroblast growth factor (bFGF) in these tumors was assessed by immunohistochemistry. The clinicopathological variables with diagnostic significance were determined by multivariate analysis, and their diagnostic values were evaluated by ROC curve analysis. PTTG, VEGF-C, MMP2, MMP9, CXCR4, and bFGF were overexpressed in metastatic papillary thyroid carcinomas, whereas p27kip1 expression was elevated only in carcinomas lacking metastasis. Multiple-factor binary ordinal logistic regression analysis revealed that PTTG, VEGF-C, MMP2, and bFGF were independently related to biological metastatic behavior in thyroid tumors, suggesting their potential use as biomarkers. ROC curve analysis showed that among these four proteins, VEGF-C and bFGF were the best diagnostic biomarkers. A VEGF-C and bFGF cluster was the most useful factor for the differential diagnosis between metastatic and non-metastatic papillary thyroid cancers. Thus, the combined use of VEGF-C and bFGF as biomarkers may improve the diagnostic accuracy of papillary thyroid carcinoma and may be useful in multimodal screening programs for the clinical diagnosis of papillary thyroid carcinoma and early detection of papillary thyroid carcinoma with distant metastasis.
