Follicular thyroid lesions, elements that affect both diagnosis and prognosis

Papillary Thyroid Cancer: Genetic Alterations and Molecular Biomarker Investigations

Papillary thyroid cancer (PTC) is the most prevalent form of malignancy among all cancers of the thyroid. It is also one of the few cancers with a rapidly increasing incidence. PTC is usually contained within the thyroid gland and generally biologically indolent. Prognosis of the cancer is excellent, with less than 2% mortality at 5 years. However, more than 25% of patients with PTC developed a recurrence during a long term follow-up. The present article provides an updated condensed overview of PTC, which focuses mainly on the molecular alterations involved and recent biomarker investigations.

Circulating thyroid stimulating hormone receptor messenger RNA and differentiated thyroid cancer: A diagnostic meta-analysis

Thyroid stimulating hormone receptor messenger RNA (TSHR-mRNA) is over-expressed in thyroid cancer patients, which indicates that TSHR-mRNA is a potential biomarker of thyroid cancer. However, system evaluation for TSHR-mRNA as a diagnostic biomarker of thyroid cancer is deficient. The performance of TSHR-mRNA for thyroid cancer diagnosis was evaluated in this study. Three common international databases as well as a Chinese database were applied for literature researching. Quality assessment of the included literatures was conducted by the QUADAS-2 tool. Totally, 1027 patients from nine studies eligible for the meta-analysis were included in this study. Global sensitivity and specificity for the positivity of TSHR-mRNA in the thyroid cancer diagnosis is 72% and 82%. The value of AUC for this test performance was 0.84. Our meta-analysis suggests that TSHR-mRNA might be a potential biomarker to complete present diagnostic methods for early and precision diagnosis of thyroid cancer. Notably, this findings need validation thorough large-scale clinical studies.

Larger tumor size predicts nodal involvement in patients with follicular thyroid carcinoma

Aims and background

Lymph node metastases are rare in patients with follicular thyroid carcinoma, with an average incidence of 5.5% of all cases reported in the literature. In the present study we focused on the search for risk factors predictive of lymph node involvement in patients with follicular thyroid carcinoma to plan the most appropriate management and follow-up.

Methods and study design

We carried out a cross-sectional study among patients with follicular thyroid carcinoma and lymph node metastasis at diagnosis and patients without lymph node involvement. From January 1998 to April 2008, 930 patients underwent thyroidectomy in our surgical department for a variety of thyroid disorders, 420 (45.2%) of them for a differentiated thyroid carcinoma. The medical records of 55 patients with histological diagnosis of follicular thyroid carcinoma were analyzed.

Results

Four patients (7.3%) had lymph node metastasis from follicular thyroid carcinoma at presentation in both the lateral and central neck compartments. Mean tumor size was significantly greater for follicular thyroid carcinomas with nodal metastasis (5.1 ± 1.4 cm) than for those without nodal involvement (3.0 ± 1.2 cm, P <0.010). Among factors supposed to influence the presence of nodal metastasis at diagnosis (age, gender, tumor size, multifocality, tumor poorly differentiated, tumor widely invasive, vascular invasion, thyroid capsular invasion, and extra thyroid invasion), tumor size larger than 4.0 cm was the only factor retained in the multivariate statistical model.

Conclusions

Lymph node dissection must be planned only in the case of large follicular thyroid carcinomas. Since follicular carcinoma is usually diagnosed postoperatively, more attention should be paid to nodal involvement in the tumor re-staging during follow-up of those patients with tumors larger than 4.0 cm in diameter.

Can Ultrasound Predict Malignancy in Patient with Thyroid Cold Nodule?

Thyroid nodule is one of the most common endocrine diseases in the world; it occurs in 4–7% of the general population. Depending on the method of discovery, 4–8% nodules are discovered using palpation, 10–41% with ultrasound (US), and 50% through autopsy where only 20% or less of cold thyroid nodules are caused by cancerous lesions. The aim of this study was to assess US as supporting modality for thyroid scintigraphy to predict malignancy in patient with thyroid cold nodules. In a retrospective study between 2009 and 2013, we analyzed 399 subjects with cold thyroid nodule, where 39 subjects (36 women and 3 men) presented with malignant thyroid cold nodule and 19 subjects underwent US. The US showed malignancy parameters in 8 (42.11%) subjects, while the rest of the 11 (57.89%) subject were benign. Out of all the subjects who underwent US in this study, only 8 (42.11%) subjects shown malignancy characteristics in cold thyroid nodule with papillary thyroid cancer (PTC). That means US parameters of malignant thyroid nodule do not always show up in malignant cold thyroid nodule.

Prognostic value of p27 in follicular thyroid carcinoma and its relation to radioactive iodine response: does it aid in the modification of risk stratification?

INTRODUCTION

Follicular thyroid carcinoma (FTC) is the second most common type of thyroid cancer. Genetic studies have demonstrated that the loss of expression and function of Cdk inhibitor p27 leads to the development of multiple-organ hyperplasia and malignancy, including thyroid carcinoma.

AIM OF WORK

(1) To assess the prognostic value of the quantitative expression of p27 in correlation with clinicopathologic prognostic indicators in FTC. (2) To explore its predictive value in the assessment of response to radioactive I-131 therapy in metastatic FTC patients.

MATERIALS AND METHODS

This retrospective study was conducted on 43 histopathologically confirmed FTC patients referred to the nuclear medicine department, National Cancer Institute, Cairo University between July 2001 and December 2010, for radioactive I-131 therapy. Clinicopathologic parameters, details of radioactive I-131 therapy and its outcome, and a serial follow-up serum thyroglobulin levels and I-131 whole body scan were obtained from their medical records. Quantitative expression of p27 using immunostaining was analyzed using paraffin blocks of thyroidectomy specimens in all patients.

RESULTS

With respect to clinicopathologic characteristics, p27 expression was found to be significantly lower in patients with vascular invasion (P=0.024) and in patients with an advanced-stage disease (P=0.048). A significant difference was detected between the risk stratification and the quantitative expression of p27. A statistically significant difference was obtained with respect to immunohistochemical expression of p27 between the metastatic and nonmetastatic patients as well as age, growth characteristics, tumor size, vascular invasion, and extrathyroidal extension. Despite the observed trend in patients with a low p27 expression, to have a worse response to iodine therapy, and a poor overall survival, the point of statistical significance could not be reached.

CONCLUSIONS

In this preliminary study, p27 quantitative expression appeared to provide a complementary valuable predictor with other prognostic variables for risk stratification in FTC patients. Response to I-131 therapy in FTC in relation to p27 expression should be thoroughly investigated including large-scale studies and more homogenous risk groups.

Pitfalls in the staging of cancer of thyroid

Thyroid cancer includes several neoplasms originating from the thyroid gland-from indolent and curable histologies of differentiated thyroid carcinoma to aggressive anaplastic thyroid carcinoma. Differentiation of thyroid nodules is problematic on CT and MR imaging unless there is evidence of extrathyroidal extension. Evaluation of regional lymph nodes is often performed clinically or with ultrasound. The retropharyngeal and mediastinal lymph nodes are better evaluated by CT and MR imaging. Nuclear scintigraphy is useful for staging and treatment of distant metastasis in differentiated thyroid carcinoma. PET may have a role in aggressive cancers. Accurate staging affects surgical management and subsequent therapy.

BRAF V600E mutation and its association with clinicopathological features of papillary thyroid cancer: a meta-analysis

BACKGROUND

There is conflicting literature regarding the association of the BRAF V600E mutation and aggressive clinicopathological features of papillary thyroid cancer (PTC). Nevertheless, some propose that BRAF status be incorporated into the management of patients with PTC, specifically recommendations regarding lymph node dissection. We therefore performed a meta-analysis to examine the relationship between BRAF and clinicopathological features of PTC.

METHODS

A literature search was performed within PubMed and EMBASE databases using the following Medical Subject Headings (MeSH) and keywords: "braf," "mutation," "thyroid," "neoplasm(s)," "tumor," "cancer," and "carcinoma." Individual study-specific odds ratios and confidence intervals were calculated, as were Mantel-Haenszel pooled odds ratios for the combined studies.

RESULTS

Thirty-two studies including 6372 patients were reviewed. BRAF mutation was associated with lymph node metastases (LNM), advanced stage, extrathyroidal extension, tumor size, male gender, multifocality, absence of capsule, classic PTC, and tall-cell variant PTC. There was no association with age or vascular invasion. Only two studies were prospective; nine included consecutive patients, whereas one included randomly selected patients; and only two included patients who had undergone routine central lymph node dissection and were thus evaluable for the presence of LNM.

CONCLUSION

Meta-analysis found that BRAF mutation is associated with LNM, stage, extrathyroidal extension, tumor size, male gender, multifocality, absence of capsule, classic PTC, and tall-cell variant PTC in PTC. However, almost all studies were retrospective and only two of 32 included patients who had undergone routine central lymph node dissection, emphasizing the need for well-designed studies to appropriately examine this association before making important clinical decisions.

Expression of CK-19, galectin-3 and HBME-1 in the differentiation of thyroid lesions: systematic review and diagnostic meta-analysis

Background

To distinguish between malignant and benign lesions of the thyroid gland histological demonstration is often required since the fine-needle aspiration biopsy method applied pre-operatively has some limitations. In an attempt to improve diagnostic accuracy, markers using immunocytochemistry and immunohistochemistry techniques have been studied, mainly cytokeratin-19 (CK-19), galectin-3 (Gal-3) and Hector Battifora mesothelial-1 (HBME-1). However, current results remain controversial. The aim of the present article was to establish the diagnostic accuracy of CK-19, Gal-3 and HBME-1 markers, as well as their associations, in the differentiation of malignant and benign thyroid lesions.

Methods

A systematic review of published articles on MEDLINE and The Cochrane Library was performed. After establishing inclusion and exclusion criteria, 66 articles were selected. The technique of meta-analysis of diagnostic accuracy was employed and global values of sensitivity, specificity, area under the summary ROC curve, and diagnostic odds ratio (dOR) were calculated.

Results

For the immunohistochemistry technique, the positivity of CK-19 for the diagnosis of malignant thyroid lesions demonstrated global sensitivity of 81% and specificity of 73%; for Gal-3, sensitivity of 82% and specificity of 81%; and for HBME-1, sensitivity of 77% and specificity of 83%. The association of the three markers determined sensitivity of 85%, specificity of 97%, and diagnostic odds ratio of 95.1. Similar results were also found for the immunocytochemistry assay.

Conclusion

This meta-analysis demonstrated that the three immunomarkers studied are accurate in pre- and postoperative diagnosis of benign and malignant thyroid lesions. Nevertheless, the search for other molecular markers must continue in order to enhance this diagnostic accuracy since the results found still show a persistency of false-negative and false-positive tests.

Virtual slides

Http://www.diagnosticpathology.diagnomx.eu/vs/3436263067345159

Thyroid nodule management: clinical, ultrasound and cytopathological parameters for predicting malignancy

Although fine-needle aspiration cytology is considered to be the reference method for evaluating thyroid nodules, the results are inaccurate in approximately 10-30% of cases. Several studies have attempted to predict the risk of malignancy in thyroid nodules based on age, nodularity, thyrotropin values, thyroid autoimmune disease, hot/cold nodule status, and ultrasound parameters. However, no consensus has been found, and none of these parameters has significantly affected patient management. The management of indeterminate thyroid nodules and re-biopsies of nodules with initially benign cytological results remain important and controversial topics of discussion. The Bethesda cytological system and several studies on the use of molecular markers to predict malignancy from cytological samples of thyroid nodules need further clarification. More in-depth discussions among and continuous education of the specialists involved in treating thyroid disease are necessary to improve the management of these patients. This review aims to examine the clinical, laboratory, ultrasound, and scintigraphic parameters that can be used for thyroid nodule management.

The quest for diagnostic molecular markers for thyroid nodules with indeterminate or suspicious cytology

Thyroid nodules are very common and fine needle aspiration (FNA) is a very sensitive means of diagnosis. However, its limitations include the fact that the cytology reports are often indeterminate or suspicious only. The quest for adjunctive measures to improve its specificity has been ongoing for decades, but significant results have remained elusive. The potential use of diagnostic molecular markers appears to be the most promising area of research at this time.

Telomere length is related to alternative splice patterns of telomerase in thyroid tumors

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.

Clinical implications of molecular markers in follicular cell-derived thyroid cancer

The increasing use/applications of molecular biology techniques have provided new insights on the genetic changes that underlie carcinogenesis and tumor progression in thyroid cancer. Molecular analysis may improve the histopathologic evaluation of follicular cell-derived thyroid carcinoma, not only elucidating some unresolved problems related to the diagnosis and disease prognosis, but also by improving patient management. Besides increasing our comprehension of cancer biology, either genetic alterations or gene expression profiles implicated in thyroid carcinogenesis shed new light on innovative diagnostic procedures as well as on targeted therapies.

Differentiating alternative splice variant patterns of human telomerase reverse transcriptase in thyroid neoplasms

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

These differences in gene expression patterns of hTERT alternative splice variants may provide a useful adjunct to FNA diagnosis of suspicious thyroid tumors.

Fine-needle aspiration of thyroid nodules: a study of 4703 patients with histologic and clinical correlations

BACKGROUND

The Papanicolaou Society of Cytopathology recently proposed 6 diagnostic categories for the classification of thyroid fine-needle aspiration (FNA) cytology. Using these categories, the experience with FNA from 2 institutions was studied with emphasis on cytologic-histologic correlation, source of errors, and clinical management.

METHODS

Patient cytology data were retrieved by a retrospective search of thyroid FNA in the institutional databases. Cytologic diagnoses were classified as unsatisfactory, benign, atypical cellular lesion (ACL), follicular neoplasm (FN), suspicious for malignancy, and positive for malignancy. Samples with a histologic discrepancy were re-evaluated, and clinical follow-up information was recorded.

RESULTS

Of 4703 FNA samples, 10.4% were classified as unsatisfactory, 64.6% were classified as benign, 3.2% were classified as ACL, 11.6% were classified as FN, 2.6% were classified as suspicious, and 7.6% were classified as malignant. Five hundred twelve patients had at least 1 repeat FNA, mainly for results in the unsatisfactory and ACL categories. One thousand fifty-two patients had surgical follow-up, including 14.9% of patients with unsatisfactory FNA results, 9.8% of patients with benign results, 40.6% of patients with ACL results, 63.1% of patients with FN results, 86.1% of patients with suspicious results, and 79.3% of patients with malignant results. The rates for histologically confirmed malignancy in these categories were 10.9%, 7.3%, 13.5%, 32.2%, 64.7%, and 98.6%, respectively. The cytologic-histologic diagnostic discrepancy rate was 15.3%. Sources of errors included diagnoses on inadequate specimens, sample errors, and overlapping cytologic features between hyperplastic nodules and follicular adenoma. The sensitivity and specificity of thyroid FNA for the diagnosis of malignancy were 94% and 98.5%, respectively.

CONCLUSIONS

The current results indicated that FNA provides an accurate diagnosis of thyroid malignancy. The 6 diagnostic categories were beneficial for triaging patients for either clinical follow-up or surgical management.

Follicular neoplasm of the thyroid--vanishing cytologic diagnosis?

The significance of making a diagnosis of follicular neoplasm on fine needle aspiration (FNA) biopsy remains a controversial issue, considering that the diagnosis of follicular carcinoma is based on histological criteria and the significantly decreasing incidence of follicular carcinoma in the general population. On FNA the main differential diagnoses of follicular neoplasm includes follicular variant of papillary carcinoma (FVPC), follicular adenoma, follicular carcinoma and benign solitary nodule occurring in a goiter. Several studies have looked at immunohistochemical and molecular markers to distinguish benign from malignant lesions but none of them have proved to be infallible. Although, FVPC is a distinct entity from the follicular neoplasm group, it is not always possible to separate it from the other follicular lesions because of overlapping cytologic features and often-sporadic presence of nuclear features, follicular variant of papillary carcinoma remains the main pitfall in a diagnosis of follicular neoplasm. Since a significant number of cases that are malignant on follow-up are usually FVPC, consequently, follicular neoplasm is an essential diagnostic consideration on FNA. In addition, follicular carcinoma, despite a decreasing incidence continues to be a real entity. Therefore, it is essential that follicular neoplasm continue to be part of our diagnostic repertoire.

Management Considerations for Differentiated Thyroid Carcinoma Presenting as a Metastasis to the Skull Base

OBJECTIVES/HYPOTHESIS

To characterize the salient features of skull base metastasis from differentiated thyroid carcinoma, discuss the diagnostic and treatment strategies, and propose rational management guidelines for such tumors.

STUDY DESIGN

Case report.

METHODS

Review of English literature from MEDLINE with the addition of our case.

RESULTS

Skull base metastasis from differentiated thyroid carcinoma is rare, with only 20 cases reported to date, including our case report. On the basis of a review of all reported cases, both follicular and papillary thyroid cancers can metastasize to the skull base. Our case is unique because the lesion extends locally into the cavernous sinus and beyond. Histopathologic diagnosis is limited by the remote location of lesions. Most tumors are highly vascular, and there is potential for significant morbidity and mortality associated with surgical resection. The overall survival ranges from less than one year to 10+ years from the discovery of the metastasis and is similar in both tumor subtypes. There is no clear consensus on the management strategy for skull base metastasis from differentiated thyroid carcinoma. Interestingly, surgical resection of both the primary and metastatic lesions yields similar survival when compared with resection of the primary tumor alone.

CONCLUSIONS

Distant metastasis from differentiated thyroid carcinoma needs to be considered in the differential diagnosis of destructive skull base lesions, regardless of the patient's age. Histopathologic tissue diagnosis should always be attempted, followed by total thyroidectomy, radioiodine, or external beam radiation, and chronic thyroid-stimulating hormone suppression. Surgical resection of the metastatic lesion should only be performed in carefully selected cases because it is associated with significant morbidity.

Markers of cell proliferation, apoptosis, and angiogenesis in thyroid adenomas: a comparative immunohistochemical and genetic investigation of functioning and nonfunctioning nodules

OBJECTIVE

To perform (i) an immunohistochemical investigation of cell proliferation, apoptosis, angiogenesis, and malignancy markers in 15 functioning and 15 nonfunctioning thyroid adenomas, and in normal adjacent tissue, and (ii) a genetic analysis of thyroid-stimulating hormone receptor (TSH-r), Gsalpha, and RAS mutations in the same group of adenomas, in order to describe their expression within tissues and to correlate them with the hormonal functioning.

DESIGN

Thirty patients who underwent surgery for a solitary thyroid nodule were included in the study. Adenomas and normal adjacent tissues were evaluated by immunohistochemistry using the following antibodies: MIB-1 for proliferative activity, bcl-2 and mutant p53 for apoptosis control, vascular endothelial growth factor-A (VEGF-A) for angiogenic activity, and galectin-3 as a marker for malignancy. To calculate microvascular density, "hot spots" were selected and defined by cells positive for CD34 staining. Genetic analysis for TSH-r, Gsalpha, and H-, K-, and N-RAS mutations was performed on adenoma specimens.

MAIN OUTCOMES

Our results evidenced that a proportion of both functioning and nonfunctioning adenomas showed immunohistochemical phenotypes similar to normal adjacent tissue. No differences were found between functioning and nonfunctioning thyroid adenomas with regard to the expression of markers associated to angiogenesis (VEGF-A, microvascular density) and apoptosis control (mutant p53, bcl-2). All adenomas resulted negative for galectin-3 immunostaining. MIB-1 was the only marker showing a substantial difference of expression between the two groups of adenomas. TSH-r mutations were found in 12 out of 15 functioning adenomas, whereas the absence of Gsalpha and H-, K-, and N-RAS mutations was demonstrated in all adenomas.

CONCLUSIONS

Our data suggest that the differences between functioning and nonfunctioning thyroid adenomas are restricted to the genetic mutations of the TSH-r, to the hormonal status of tumors, and to the proliferative activity, not involving markers of apoptosis control and angiogenesis.

Thyroid-stimulating hormone receptor messenger ribonucleic acid measurement in blood as a marker for circulating thyroid cancer cells and its role in the preoperative diagnosis of thyroid cancer

CONTEXT

Thyroid cancer cells express TSH receptor (TSHR) mRNA, and its measurement in the circulation may be useful in the diagnosis/management of differentiated thyroid cancer (DTC).

OBJECTIVE

Our objective was to assess the diagnostic value of circulating TSHR mRNA for preoperative detection of DTC in patients with thyroid nodules.

PATIENTS

We measured TSHR mRNA levels by RT-PCR in 258 subjects: 51 healthy subjects and 207 patients (thyroid nodules, n = 180; recurrent thyroid cancer, n = 27) with fine-needle aspirations (FNA) and/or thyroid/neck surgery. Eighty-nine patients also had d-1 postoperative levels assessed.

OUTCOME MEASURES

TSHR mRNA levels were compared with FNA cytology for cancer detection preoperatively and serum thyroglobulin and/or whole-body 131I scans postoperatively.

RESULTS

Based on cytology/pathology, 88 patients had DTC and 119 had benign thyroid disease. The TSHR mRNA levels in cancer patients were significantly higher than in benign disease (P < 0.0001). At a cutoff value of 1.02 ng/microg total RNA, the TSHR mRNA correctly classified 78.7% of patients preoperatively (sensitivity = 72.0%; specificity = 82.5%). Of 131 patients with FNA and surgery, 51 were FNA positive (all cancer), 17 were FNA negative (15 benign, two cancer), and 63 were indeterminate. TSHR mRNA correctly diagnosed DTC in 16 of 24 (67%) and benign disease in 29 of 39 (74%) patients with indeterminate FNA (combined sensitivity = 90%; specificity = 80%). Combining TSHR mRNA and ultrasound features for follicular lesions correctly classified all follicular cancers and could have spared surgery in 31% of these patients with benign disease. TSHR mRNA has a short life in circulation, and normalized levels on postoperative d 1 correlated with disease-free status, whereas elevated levels predicted residual/metastatic disease.

CONCLUSIONS

TSHR mRNA measured with FNA enhances the preoperative detection of cancer in patients with thyroid nodules, reducing unnecessary surgeries, and immediate postoperative levels can predict residual/metastatic disease.

The utility of peripheral thyrotropin mRNA in the diagnosis of follicular neoplasms and surveillance of thyroid cancers

BACKGROUND

Thyroid cells in peripheral circulation express uniquely thyrotropin receptor (TSHR) mRNA, and their detection may aid thyroid cancer management.

METHODS

Since 2002, 258 patients had prospective TSHR mRNA measurement by quantitative RT-PCR from peripheral blood before and/or after thyroidectomy. Thyroid cancer detection was assessed from known clinical diagnostic criteria and mRNA for patients with follicular neoplasms (n = 64) and long-term cancer follow-up (n = 13).

RESULTS

Adding TSHR mRNA to fine-needle aspiration biopsy (FNAB) maintained high sensitivity (90%) but improved specificity (73%) for thyroid cancer diagnosis. When FNAB specimens indicated follicular neoplasm, a decision algorithm combining TSHR mRNA and abnormal thyroid ultrasound features correctly diagnosed all cancer patients (100% sensitivity) and would have spared operation for benign disease in 38%. Elevated TSHR mRNA on postoperative day 1 predicted persistent/recurrent cancer. During long-term thyroid cancer surveillance, TSHR mRNA had a 91% concordance with radioactive iodine whole body scan (WBS)-detectable disease, agreed with thyroglobulin (Tg) levels in 64% of patents, missed disease in 5%, but was more sensitive to detecting disease than Tg levels in 31% of patients, including all patients with Tg antibodies.

CONCLUSIONS

Detecting circulating thyroid cancer cells is useful for initial thyroid cancer diagnosis and postoperatively predicts recurrent cancer. This novel test promises to enhance thyroid cancer patient care by management algorithms that combine histologic, genomic, and clinical criteria.

Prognostic Factors in Papillary and Follicular Thyroid Carcinoma: Their Implications for Cancer Staging

BACKGROUND

Papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC) are two distinct histological types of thyroid carcinoma but have often been studied and staged as a collective group, known as differentiated thyroid carcinoma (DTC). However, this may not be an optimal approach to cancer staging.

METHODS

A total of 760 patients with DTC, comprising 589 (77.5%) with PTC and 171 with (22.5%) FTC, being managed at our institution from 1961 to 2001 were retrospectively reviewed. Their clinicopathological features, treatment modalities received, and postoperative outcome were analyzed. Both univariate and multivariate analyses were performed to identify prognostic factors related to cancer-specific survival (CSS) for PTC and FTC.

RESULTS

There were statistically significant differences between PTC and FTC in terms of age >/=50 years at diagnosis (P = .040), tumor size (P < .001), lymph node metastases (P < .001), distant metastases (P < .001), extrathyroidal extension (P < .001), multifocality (P = .002), capsular invasion (P < .001), extent of thyroid resection (P < .001), radioiodine ablation (P < .001), and external-beam irradiation (P = .003). Although PTC and FTC had similar 10-year and 15-year CSS (P = .846), each possessed its own set of independent prognostic factors for CSS. Age at diagnosis and completeness of resection were independent prognostic factors in both PTC and FTC.

CONCLUSIONS

There were marked differences in clinicopathologic features, treatment, and prognostic factors between the two histologic types of DTC. Different staging systems should be evaluated and validated for PTC and FTC individually in the future.

Promising molecular techniques for discriminating among follicular thyroid neoplasms

To guide the extent of thyroidectomy for indeterminate follicular neoplasm (FN), clinicians have long sought ways to differentiate follicular adenoma from carcinoma pre- or intraoperatively. Several promising molecular techniques have recently appeared including loss of heterozygosity analysis and molecular profiling microarray analysis. These new tools may also prove useful in determining prognosis, thus and allow a paradigm change in current management of the thyroid nodule.

A six-gene model for differentiating benign from malignant thyroid tumors on the basis of gene expression

BACKGROUND

Thyroid nodules are common; fine-needle aspirations commonly are read as indeterminate, necessitating surgery to exclude carcinoma. We developed a 6-gene array-based predictor model to diagnose benign versus malignant thyroid lesions. In this study, we verified whether quantitative reverse transcription-polymerase chain reaction (qRT-PCR) using this model reliably can differentiate benign from malignant thyroid nodules.

METHODS

Molecular profiles of benign (follicular adenomas, hyperplastic nodules) and malignant tumors (papillary thyroid carcinomas, follicular variants of papillary thyroid carcinomas) were analyzed using qRT-PCR from our 6-gene model (kit, Hs.296031, Hs.24183, LSM7, SYNGR2, C21orf4). The gold standard was standard pathologic criteria. A diagnosis-predictor model was built by using the training samples and was then used to predict the class of 10 additional samples analyzed as unknowns.

RESULTS

Our predictor model using 47 training samples correctly predicted 9/10 unknowns. One sample diagnosed as benign by standard histologic criteria was diagnosed as malignant by our model (sensitivity 75%; specificity, 100%; positive predictive value, 100%; negative predictive value, 85.7%).

CONCLUSIONS

Molecular diagnosis with our 6-gene model can differentiate between benign and malignant thyroid tumors with high sensitivity and specificity. In combination, these genetic markers may be a reliable test to preoperatively diagnose the malignant potential of thyroid nodules.