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ABSTRACT: BACKGROUND: Some have proposed using V600E BRAF mutation status to dictate the surgical management of patients with papillary thyroid cancer (PTC). However, well-designed studies examining BRAF association with aggressive clinicopathologic features of PTC, including the presence of lymph node metastases (LNM), in patients who have undergone routine central lymph node dissection (CLND), are lacking. METHODS: Under institutional review board approval, 63 patients diagnosed with PTC on fine-needle aspiration who underwent total thyroidectomy and CLND were included. BRAF mutation status was determined in fresh frozen or intraoperative fine-needle aspiration samples with a colorimetric assay. Associations between BRAF mutation status and clinicopathologic features of PTC were examined using Chi-square and multivariate logistic regression analyses. RESULTS: BRAF mutation was found to be significantly associated with race only on Chi-square analysis. BRAF mutation was not found to be significantly associated with the presence of LNM (P = .167). On multivariate analysis, only size and venous/lymphatic invasion were significantly associated with LNM. CONCLUSION: This small series underscores the prematurity in utilizing BRAF mutation status to determine the surgical management of patients with PTC, specifically whether or not to perform a CLND.
Surgery 10/2012; · 3.10 Impact Factor
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Nijaguna B Prasad,
Jeanne Kowalski,
Hua-Ling Tsai,
Kristin Talbot,
Helina Somervell,
Guennadi Kouniavsky, Yongchun Wang,
Alan P B Dackiw,
William H Westra,
Douglas P Clark,
Steven K Libutti,
Christopher B Umbricht,
Martha A Zeiger
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ABSTRACT: The preoperative diagnosis of thyroid nodules primarily depends upon fine needle aspiration (FNA) cytology. However, up to 25% of FNA samples have associated "suspicious or indeterminate", but not diagnostic cytologic reports, resulting in difficulty deciding appropriate clinical management for these patients. We hypothesize that the use of molecular markers as an adjunct to FNA cytology can improve the distinction of benign from malignant nodules that have associated suspicious or indeterminate cytology.
Using microarray analysis, we previously identified and reported on 75 genes useful in the distinction of benign versus malignant thyroid nodules. In the present study, we have further validated the expression of 14 of these markers in a large number of thyroid samples by immunohistochemistry (IHC) analysis of 154 thyroid tumors and quantitative real-time RT-PCR (QRT-PCR) analysis of 95 FNA samples. Of the 154 tumors analyzed by IHC, 44 samples (29%) had associated suspicious or indeterminate FNA cytology.
Receiver operating characteristic using three-gene model, (HMGA2, MRC2, and SFN) analysis for the detection of malignant nodules resulted in areas under the curve (AUCs) of≥0.95 (80% sensitivity; 100% specificity) and≥0.84 (71% sensitivity; 84% specificity) for the IHC data in tumors, and QRT-PCR data in FNA samples, respectively.
Our results suggest that a three-gene model for the cytological diagnosis of indeterminate thyroid nodules is both feasible and promising. Implementation of this as an adjunct to thyroid cytology may significantly impact the clinical management of patients with suspicious or indeterminate thyroid FNA nodules.
Thyroid: official journal of the American Thyroid Association 03/2012; 22(3):275-84. · 2.60 Impact Factor
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ABSTRACT: Thyroid cancer diagnosis in the United States has increased by 2.3-folds in the last three decades. Up to 30% of thyroid fine-needle aspiration biopsy (FNAB) results are inconclusive. Several differentially expressed microRNAs (miRNAs) have been identified as candidate diagnostic markers for thyroid nodules. We hypothesized that these differentially expressed miRNAs may improve the accuracy of FNAB in difficult to diagnose thyroid nodules.
Expression levels of four miRNAs (miR-7, -126, -374a, and let-7g) were analyzed using quantitative real-time reverse transcription-polymerase chain reaction in 95 FNAB samples as the training set. A predictor model was formulated based on the most differentially expressed miRNA (miR-7) ΔCt value and the model was applied on a separate cohort of 59 FNAB samples as the validation set.
miR-7 was the best predictor to distinguish benign from malignant thyroid FNAB samples. The other three miRNAs were co-expressed and did not significantly contribute to the predictor model. miR-7 had a sensitivity of 100%, specificity of 29%, positive predictive value (PPV) of 36%, negative predictive value (NPV) of 100%, and overall accuracy of 76% when applied to the validation set. In subgroup analysis of preoperative nondiagnostic, indeterminate, or suspicious FNAB samples, the predictor model had an overall accuracy of 37% with sensitivity of 100%, specificity of 20%, PPV of 25%, and NPV of 100%.
miR-7 may be a helpful adjunct marker to thyroid FNAB in tumor types which are inconclusive. Given the high NPV of miR-7, a patient with a benign result based on the predictor model may be followed as opposed to performing an immediate diagnostic thyroidectomy. Future prospective clinical trials evaluating its accuracy in a larger cohort are warranted to determine its clinical utility.
Thyroid: official journal of the American Thyroid Association 03/2012; 22(3):285-91. · 2.60 Impact Factor
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Nijaguna Prasad,
Jeanne Kowalski,
Hua-Ling Tsai,
Kristin Talbot,
Helina Somervell,
Guennadi Kouniavsky, Yongchun Wang,
Alan Dackiw,
William H Westra,
Douglas P Clark,
Steven K Libutti,
Christopher B Umbricht,
Martha A Zeiger
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ABSTRACT: Background: The preoperative diagnosis of thyroid nodules primarily depends upon fine needle aspiration (FNA) cytology. However, up to 25% of FNA samples have associated 'suspicious or indeterminate', but not diagnostic cytologic reports, resulting in difficulty deciding appropriate clinical management for these patients. We hypothesize that the use of molecular markers as an adjunct to FNA cytology can improve the distinction of benign from malignant nodules that have associated suspicious or indeterminate cytology. Methods: Using microarray analysis, we previously identified and reported on 75 genes useful in the distinction of benign vs. malignant thyroid nodules. In the present study, we have further validated the expression of 14 of these markers in a large number of thyroid samples by immunohistochemistry (IHC) analysis of 154 thyroid tumors and real-time RT-PCR (QRT-PCR) analysis of 95 FNA samples. Of the 154 tumors analyzed by IHC, 44 samples (29%) had associated suspicious or indeterminate FNA cytology. Results: Receiver operating characteristic (ROC) analysis of the IHC data in tumors and QRT-PCR data in FNA samples, using the 3-gene model, (HMGA2, MRC2, and SFN) resulted in AUC ≥ 0.95 [80% sensitivity; 100% specificity] and AUC ≥ 0.84 [71% sensitivity; 84% specificity], respectively for the detection of malignant nodules. Conclusions: Our results suggest that a 3-gene model for the cytological diagnosis of indeterminate thyroid nodules is both feasible and promising. Implementation of this as an adjunct to thyroid cytology may significantly impact the clinical management of patients with suspicious or indeterminate thyroid FNA nodules.
Thyroid: official journal of the American Thyroid Association 12/2011; · 2.60 Impact Factor
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Yongchun Wang,
Alan K Meeker,
Jeanne Kowalski,
Hua-Ling Tsai,
Helina Somervell,
Christopher Heaphy,
Lauren E Sangenario,
Nijaguna Prasad,
William H Westra,
Martha A Zeiger,
Christopher B Umbricht
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ABSTRACT: Telomere dysfunction and aberrant telomerase expression play important roles in tumorigenesis. In thyroid tumors, three possibly inhibitory splice variants of the active full-length isoform of human telomerase reverse transcriptase (hTERT) may be expressed. These variants might regulate telomerase activity and telomere length because it is the fraction of the full-length isoform, rather than the total transcript level, that correlates with enzymatic activity. Telomerase reactivation may be critical in the early stages of tumorigenesis, when progressive telomere shortening may be limiting cell viability. The aim of this study was to investigate the relationship between telomere length and hTERT splice variant expression patterns in benign and well-differentiated malignant thyroid tumors. Telomere lengths of 61 thyroid tumors were examined by fluorescence in situ hybridization, comparing tumors with adjacent normal thyroid tissue on the same slide. Expression patterns of hTERT splice variants were evaluated by quantitative and nested RT-PCR. Telomere length was inversely correlated with percentage of full-length hTERT expression rather than with total hTERT expression levels. Short telomeres and high fractions of full-length hTERT transcripts were associated with follicular and papillary thyroid carcinomas, whereas long telomeres and low levels of full-length hTERT were associated with benign thyroid nodules. Intermediate levels of full-length hTERT and telomere length were found in follicular variant of papillary thyroid carcinomas and follicular adenomas.
American Journal Of Pathology 09/2011; 179(3):1415-24. · 4.89 Impact Factor
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ABSTRACT: The incidence of thyroid cancer is increasing worldwide. The findings of up to 30% of thyroid fine-needle aspiration biopsies (FNAB) are inconclusive, primarily as a result of several thyroid histologic subtypes with overlapping cytologic features. MicroRNAs (miRNAs) are small noncoding RNAs and have been implicated in carcinogenesis. We hypothesized that there are miRNAs that are differentially expressed between benign and malignant thyroid tumors that are difficult to distinguish by FNAB.
The expression of 1263 human miRNAs was profiled in 47 tumor samples representing difficult to diagnose histologic subtypes of thyroid neoplasm (21 benign, 26 malignant). Differentially expressed miRNAs were validated by quantitative real-time reverse transcriptase-polymerase chain reaction. The area under the receiver operating characteristic curve (AUC) was used to determine the diagnostic accuracy of differentially expressed miRNAs.
Supervised hierarchical cluster analysis demonstrated grouping of 2 histologies (papillary and follicular thyroid carcinoma). A total of 34 miRNAs were differentially expressed in malignant compared to benign thyroid neoplasms (P<0.05). A total of 25 of the 34 nonproprietary miRNAs were selected for validation, and 15 of the 25 miRNAs were differentially expressed between benign and malignant samples with P-value<0.05. Seven miRNAs had AUC values of >0.7. miR-7 and miR-126 had the highest diagnostic accuracy with AUCs values of 0.81 and 0.77, respectively.
To our knowledge, this is the first study to evaluate the diagnostic accuracy of miRNAs in thyroid histologies that are difficult to distinguish as benign or malignant by FNAB. miR-126 and miR-7 had high diagnostic accuracy and could be helpful adjuncts to thyroid FNAB.
Annals of Surgical Oncology 05/2011; 18(12):3443-52. · 4.17 Impact Factor
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Chung-Che Charles Wang,
Lyssa Friedman,
Giulia C Kennedy,
Hui Wang,
Electron Kebebew,
David L Steward,
Martha A Zeiger,
William H Westra, Yongchun Wang,
Elham Khanafshar,
Giovanni Fellegara,
Juan Rosai,
Virginia Livolsi,
Richard B Lanman
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ABSTRACT: Fine-needle aspiration (FNA) biopsies are the cornerstone of preoperative evaluation of thyroid nodules, but FNA diagnostic performance has varied across different studies. In the course of collecting thyroid FNA specimens for the development of a molecular diagnostic test, local cytology and both local and expert panel surgical pathology results were reviewed.
Prospective FNAs were collected at 21 clinical sites. Banked FNAs were collected from two academic centers. Cytology and corresponding local and expert panel surgical pathology results were compared to each other and to a meta-review of 11 recently published U.S.-based thyroid FNA studies.
FNA diagnostic performance was comparable between the study specimens and the meta-review. Histopathology malignancy rates for prospective clinic FNAs were 34% for cytology indeterminate cases and 98% for cytology malignant cases, comparable to the figures found in the meta-review (34% and 97%, respectively). However, histopathology malignancy rates were higher for cytology benign cases in the prospective clinic FNA subcohort (11%) than in the meta-review (6%, with meta-review rates of 10% at community sites and 2% at academic centers, p < 0.0001). Resection rates for prospective clinic FNAs were also comparable to the meta-review for both cytology indeterminate cases (62% vs. 59%, respectively) and cytology malignant cases (82% vs. 81%, respectively). Surgical pathology categorical disagreement (benign vs. malignant diagnosis) was higher between local pathology and a consensus of the two expert panelists (11%) than between the two expert panelists both pre- (8%) and postconferral (3%).
Although recent guidelines for FNA biopsy and interpretation have been published, the rates of false-positive and false-negative results remain a challenge. Two-thirds of cytology indeterminate cases were benign postoperatively and may decrease with the development of an accurate molecular diagnostic test. High disagreement rates between local and expert panel histopathology diagnosis suggests that central review for surgical diagnoses should be used when developing diagnostic tests based on resected thyroid specimens.
Thyroid: official journal of the American Thyroid Association 12/2010; 21(3):243-51. · 2.60 Impact Factor
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ABSTRACT: To review cutting-edge, novel, implemented and potential translational research and to provide a glimpse into rich, innovative, and brilliant approaches to everyday surgical problems.
Scientific literature and unpublished results.
Articles reviewed were chosen based on innovation and application to surgical diseases.
Each section was written by a surgeon familiar with cutting-edge and novel research in their field of expertise and interest.
Articles that met criteria were summarized in the manuscript.
Multiple avenues have been used for the discovery of improved means of diagnosis, treatment, and overall management of patients with surgical diseases. These avenues have incorporated the use of genomics, electrical impedence, statistical and mathematical modeling, and immunology.
Archives of surgery (Chicago, Ill.: 1960) 02/2010; 145(2):187-96. · 4.32 Impact Factor
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Yongchun Wang,
Jeanne Kowalski,
Hua-Ling Tsai,
Radharani Marik,
Nijaguna Prasad,
Helina Somervell,
Pang-Kuo Lo,
Lauren E Sangenario,
Lars Dyrskjot,
Torben F Orntoft,
William H Westra,
Alan K Meeker,
James R Eshleman,
Christopher B Umbricht,
Martha A Zeiger
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ABSTRACT: Although fine-needle aspiration (FNA) biopsy of thyroid nodules is very sensitive in detecting thyroid malignancy, it remains ambiguous in 20-30% of cases. Current biomarkers for thyroid cancer lack either the sensitivity or specificity to substantially address this clinical problem. The aim of this study was to investigate the gene expression patterns of human telomerase reverse transcriptase (hTERT) alternative splice variants in benign and malignant thyroid tumors in an attempt to find a more reliable biomarker in the differential diagnosis of thyroid nodules.
One hundred and thirty-three thyroid tumors from eight histopathological tumor types were collected from patients undergoing thyroid surgery at Johns Hopkins Hospital. Gene expression patterns of hTERT alternative splice variants were investigated in the tumors by nested reverse transcriptase-PCR. Telomerase enzyme activity was evaluated in a subset of 16 samples associated with the different hTERT patterns. Association of c-myc expression and hTERT patterns was also examined.
Malignant thyroid tumors exhibited a greater proportion of the active full-length hTERT transcript (0.57 +/- 0.15) than inactive splice variants, alpha(-) (0.13 +/- 0.02), or beta(-)/alpha(-)beta(-) deletion transcripts (0.30 +/- 0.11; p < 0.001). The opposite was observed in benign tumors, which exhibited greater proportions of beta(-)/alpha(-)beta(-) deletion transcripts (0.64 +/- 0.08) than either the full-length (0.19 +/- 0.06) or alpha(-) deletion transcripts (0.17 +/- 0.02; p < 0.001). Similar results were observed among a diagnostically challenging subset of 50 thyroid tumors that were suspicious for malignancy on FNA. Further, increased telomerase enzymatic activity was only associated with expression of the full-length hTERT isoform. In contrast, c-myc expression, which has been implicated in hTERT regulation, correlated with overall hTERT transcription without specificity for expression of the full-length isoform.
These differences in gene expression patterns of hTERT alternative splice variants may provide a useful adjunct to FNA diagnosis of suspicious thyroid tumors.
Thyroid: official journal of the American Thyroid Association 10/2008; 18(10):1055-63. · 2.60 Impact Factor
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Nijaguna B Prasad,
Helina Somervell,
Ralph P Tufano,
Alan P B Dackiw,
Michael R Marohn,
Joseph A Califano, Yongchun Wang,
William H Westra,
Douglas P Clark,
Christopher B Umbricht,
Steven K Libutti,
Martha A Zeiger
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ABSTRACT: Although fine-needle aspiration biopsy is the most useful diagnostic tool in evaluating a thyroid nodule, preoperative diagnosis of thyroid nodules is frequently imprecise, with up to 30% of fine-needle aspiration biopsy cytology samples reported as "suspicious" or "indeterminate." Therefore, other adjuncts, such as molecular-based diagnostic approaches are needed in the preoperative distinction of these lesions.
In an attempt to identify diagnostic markers for the preoperative distinction of these lesions, we chose to study by microarray analysis the eight different thyroid tumor subtypes that can present a diagnostic challenge to the clinician.
Our microarray-based analysis of 94 thyroid tumors identified 75 genes that are differentially expressed between benign and malignant tumor subtypes. Of these, 33 were overexpressed and 42 were underexpressed in malignant compared with benign thyroid tumors. Statistical analysis of these genes, using nearest-neighbor classification, showed a 73% sensitivity and 82% specificity in predicting malignancy. Real-time reverse transcription-PCR validation for 12 of these genes was confirmatory. Western blot and immunohistochemical analyses of one of the genes, high mobility group AT-hook 2, further validated the microarray and real-time reverse transcription-PCR data.
Our results suggest that these 12 genes could be useful in the development of a panel of markers to differentiate benign from malignant tumors and thus serve as an important first step in solving the clinical problem associated with suspicious thyroid lesions.
Clinical Cancer Research 06/2008; 14(11):3327-37. · 7.74 Impact Factor
