Differential Clinicopathological Risk and Prognosis of Major Papillary Thyroid Cancer Variants

The clinicopathological significance of Ki67 in papillary thyroid carcinoma: a suitable indicator?

Background

To explore Ki67 expression in papillary thyroid carcinoma (PTC) and its clinical-pathological significance.

Methods

A total of 776 consecutive PTC and benign thyroid disease patients underwent thyroidectomy at Shanghai General Hospital from January 2013 to December 2015 and were retrospectively analysed. Ki67 expression was determined in the PTC and benign thyroid disease tissues, and other clinicopathological factors were identified via statistical analyses.

Results

The Ki67 expression intensity in the PTC group was significantly higher than that in the benign thyroid disease group. In the PTC group, a tumour size ≥ 1 cm and coexistence with thyroiditis were significantly associated with the Ki67 expression intensity. The TGAb and TPOAb plasma levels were linearly correlated with the Ki67 expression intensity. Moreover, the tumour size and Ki67 expression intensity also showed a linear correlation. Receiver operating characteristic (ROC) curve analysis suggested that the optimal cut-off value of Ki67 was 2.50%. Two groups divided by Ki67 cut-off values showed significant differences in the recurrence survival rate.

Conclusions

Ki67 is a suitable biomarker for distinguishing PTC from benign thyroid disease. Ki67 expression was related to the tumour size, thyroiditis and plasma levels of TGAb and TPOAb in PTC. Ki67 could be used as a prognostic indicator in PTC. Patients with high Ki67 expression are more likely to experience disease recurrence.

Risk factors associated with intrathyroid extension of thyroid microcarcinomas

PURPOSE

The aims of this study were to investigate the rate of intrathyroid extension of papillary thyroid microcarcinoma (PTMC) in patients operated for benign thyroid disease and to identify independent risk factors associated with it.

METHODS

A retrospective study of 301 patients operated for benign thyroid diseases (hyperthyroid diseases, multinodular goitre, Hashimoto thyroiditis and benign thyroid tumours) was performed at a high-volume endocrine surgery unit of a tertiary referral academic hospital, in a 5-year period. These patients had a PTMC incidentally discovered on definite histopathological findings following total or near-total thyroidectomy. Since distinguishing between intrathyroid extension of PTMC as the result of intrathyroid dissemination or as the result of multicentricity is challenging, we observed them together as multifocality. In statistical analysis, we used standard descriptive statistics and univariate and multivariate logistic regression analysis to determine independent risk factors associated with multifocality.

RESULTS

In our study, there were 85.4% females and 14.6% males with a median age of 54 years. A multinodular goitre (32.5%) was the most common indication for an operation. Most patients (68.4%) had a PTMC that was 5 mm or smaller. The most frequent histological variants of PTMC were the follicular variant (52.8%), followed by the papillary variant (22.6%) and the mixed follicular-papillary variant (18.6%). A multifocal PTMC was present in 26.6% of cases. An independent protective factor for multifocality of PTMC was a thyroid gland that weighed more than 38 g (OR 0.55, 95% CI 0.31-0.97, p = 0.039). Size of PTMC greater than 5 mm was an independent risk factor for a multifocal PTMC (OR 3.26, 95% CI 1.85-5.75, p = 0.000). Finally, the mixed follicular-papillary variant of PTMC represents an independent risk factor for a multifocal PTMC (OR 2.42, 95% CI 1.09-5.36, p = 0.030).

CONCLUSIONS

Intrathyroid extension is present in more than a quarter of PTMCs found in patients operated for benign thyroid disease. Independent risk factors for intrathyroid extension are size of PTMC greater than 5 mm and the mixed follicular-papillary variant of PTMC, while a large thyroid gland is an independent protective factor.

Aggressive Variants of Papillary Thyroid Carcinoma: Hobnail, Tall Cell, Columnar, and Solid

Papillary thyroid carcinomas are the most common endocrine cancer and are usually associated with good survival. However, some variants of papillary thyroid carcinomas may behave more aggressively than classic papillary thyroid carcinomas. The tall cell variant of papillary thyroid carcinoma is the most common aggressive variant of papillary thyroid carcinoma. The aggressive behavior has been ascribed to the histologic subtype and/or to the clinicopathologic features, an issue that remains controversial. The columnar variant of papillary thyroid carcinoma can be aggressive, particularly in older patients, with larger tumors showing a diffusely infiltrative growth pattern and extrathyroidal extension. A papillary thyroid carcinoma is designated as solid/trabecular variant when all or nearly all of a tumor not belonging to any of the other variants has a solid, trabecular, or nested (insular) appearance. This tumor must be distinguished from poorly differentiated thyroid carcinoma which has the same growth pattern but lacks nuclear features of papillary thyroid carcinoma and may show tumor necrosis and high mitotic activity. New to the fourth edition of the WHO Classification of Tumours of Endocrine Organs, the hobnail variant of papillary thyroid carcinoma is a moderately differentiated papillary thyroid carcinoma variant with aggressive clinical behavior and significant mortality. All of these variants are histologically unique and important to recognize due to their aggressive behavior.

Characteristics of Follicular Variant Papillary Thyroid Carcinoma in a Pediatric Cohort

CONTEXT

In adults, noninvasive follicular variant of papillary thyroid carcinoma (FVPTC) is considered a low risk for metastasis and persistent/recurrent disease.

OBJECTIVE

The goal of this study was to assess the clinical, sonographic, and histopathologic features of FVPTC in a pediatric cohort.

DESIGN

A retrospective review of subjects <19 years of age with papillary thyroid carcinoma (PTC) who underwent thyroidectomy between January 2010 and July 2015.

SETTING

Multidisciplinary academic referral center.

PATIENTS

Patients with FVPTC, defined as a tumor ≥1 cm in the largest dimension with predominant follicular growth, complete lack of well-formed papillae, and nuclear features of PTC.

MAIN OUTCOME MEASURES

Tumor size and location, presence of a tumor capsule, capsule and vascular invasion, lymph node invasion, and distant metastasis.

RESULTS

Eighteen patients with FVPTC were identified from a case cohort of 110 patients with PTC. On histopathology, 13 (72%) had unifocal nodules and 14 (78%) had completely encapsulated FVPTC. Capsule invasion was frequent (nine of 14; 64%), and vascular invasion was found in one-third of patients (six of 18; 33%). No lymph node metastases were found in the 13 patients (72%) who had a central neck lymph node dissection. One patient with vascular invasion had distant metastases.

CONCLUSION

When strictly defined, FVPTC in pediatric patients has a low risk for bilateral disease and metastasis. Prospective studies are needed to confirm whether lobectomy with surveillance is sufficient to achieve remission in pediatric patients with low-risk FVPTC.

BRAF V600E Mutation-Assisted Risk Stratification of Solitary Intrathyroidal Papillary Thyroid Cancer for Precision Treatment

Background

Precise risk stratification-based treatment of solitary intrathyroidal papillary thyroid cancer (SI-PTC) that is larger than 1.0 cm and 4.0 cm or less is undefined.

Methods

A genetic-clinical risk study was performed on BRAF V600E in 955 patients (768 women and 187 men) with SI-PTC, with median age of 46 years and median clinical follow-up time of 64 months at 11 medical centers in six countries. The chi-square test or, for analyses with small numbers, Fisher's exact test was performed to compare recurrence rates. Recurrence-free probability was estimated by Kaplan-Meier (KM) analysis, and the independent effect of BRAF mutation on the recurrence was analyzed by Cox regression and Cox proportional hazard analyses. All statistical tests were two-sided.

Results

Recurrence of SI-PTC larger than 1.0 cm and 4.0 cm or less was 9.5% (21/221) vs 3.4% (11/319) in BRAF mutation vs wild-type BRAF patients, with a hazard ratio (HR) of 3.03 (95% confidence interval [CI] = 1.46 to 6.30) and a patient age- and sex-adjusted hazard ratio of 3.10 (95% CI = 1.49 to 6.45, P = .002). Recurrence rates of SI-PTC larger than 2.0 cm and 4.0 cm or less were 16.5% (13/79) vs 3.6% (5/139) in mutation vs wild-type patients (HR = 5.44, 95% CI = 1.93 to 15.34; and adjusted HR = 5.58, 95% CI = 1.96 to 15.85, P = .001). Recurrence rates of SI-PTC larger than 3.0 cm and 4 cm or less were 30.0% (6/20) vs 1.9% (1/54) in mutation vs wild-type patients (HR = 18.40, 95% CI = 2.21 to 152.98; and adjusted HR = 14.73, 95% CI = 1.74 to 124.80, P = .01). Recurrences of mutation-positive SI-PTC were comparable with those of counterpart invasive solitary PTC, around 20% to 30%, in tumors larger than 2.0 cm to 3.0 cm. BRAF mutation was associated with a statistically significant decrease in recurrence-free patient survival on KM analysis, particularly in SI-PTC larger than 2.0 cm and 4.0 cm or less. Similar results were obtained in conventional SI-PTC. The negative predictive values of BRAF mutation for recurrence were 97.8% (95% CI = 96.3% to 98.8%) for general SI-PTC and 98.2% (95% CI = 96.3% to 99.3%) for conventional SI-PTC.

Conclusions

BRAF V600E identifies a subgroup of SI-PTC larger than 1.0 cm and 4.0 cm or less, particularly tumors larger than 2.0 cm and 4.0 cm or less, that has high risk for recurrence comparable with that of invasive solitary PTC, making more aggressive treatment reasonable.

BRAF V600E mutation in papillary thyroid cancer and its effect on postoperative radioiodine (131I) therapy: Should we modify our therapeutic strategy?

INTRODUCTION

The BRAF V600E mutation in papillary thyroid cancer (PTC) has been associated with resistance to ¹³¹I. Our aim was to quantify the response to ¹³¹I after surgery in patients who had the mutation (BRAF+) and those who did not have the mutated gene (BRAF-).

METHOD

A prospective cohort study was designed, from September 2015 to February 2016, which included patients with PTC receiving therapy after surgical treatment. Variables were described for age, gender, histology, tumor stage, thyroglobulin values before, 48h after and 6months after ¹³¹I; absorbed dose and % activity on days 2 and 7 and elimination time.

RESULTS

41 patients giving in total 67 thyroid remnants were included. 61% were BRAF+. In stagesiii and iv, 80% were BRAF+. In lateral resection, 100% were BRAF+. The number of nodes was higher in BRAF+: 3.4 vs 1.2 (P=.01). The classic variant was predominant in BRAF+ (91.7% vs 8.3%, P=.03). 85.7% vs 14.3% of BRAF+ had desmoplastic reaction (P=.02). The BRAF+ had a lower absorbed dose than the administered activity (5.4Gy/MBq vs 20Gy/MBq, P=.02); lower% activity with respect to the unit of mass at 2 (0.046%/g vs 0.103%/g, P=.02) and at 7days (0.006%/gr vs 0.034%/gr, P=.04) CONCLUSIONS: The mutation of the BRAF V600E gene is related with greater resistance to postoperative treatment with ¹³¹I since the onset of the disease.

CRLF1 promotes malignant phenotypes of papillary thyroid carcinoma by activating the MAPK/ERK and PI3K/AKT pathways

Papillary thyroid carcinoma (PTC) is the one of the most common types of endocrine cancer and has a heterogeneous prognosis. Tumors from patients with poor prognosis may differentially express specific genes. Therefore, an analysis of The Cancer Genome Atlas (TCGA) database was performed and revealed that cytokine receptor-like factor 1 (CRLF1) may be a potential novel target for PTC treatment. The objective of the current study was to explore the expression of CRLF1 in PTC and to investigate the main functions and mechanisms of CRLF1 in PTC. PTC tissues exhibited higher CRLF1 expression at both the mRNA and protein levels than it did with normal thyroid tissues. High CRLF1 levels were associated with aggressive clinicopathological features and poor disease-free survival rates. By using loss-of-function and gain-of-function assays, we found that CRLF1 not only increased cell migration and invasion in vitro but also promoted tumor growth both in vitro and in vivo. In addition, CRLF1 induced epithelial–mesenchymal transitions. Overexpression of CRLF1 activated the ERK1/2 and AKT pathways. The oncogenic effects induced by CRLF1 were suppressed by treating the cells with the MEK inhibitor U0126 or the AKT inhibitor MK-2206. These results suggest that CRLF1 enhances cell proliferation and metastasis in PTC and thus may therefore be a potential therapeutic target for PTC.

Epigenetically upregulated WIPF1 plays a major role in BRAF V600E-promoted papillary thyroid cancer aggressiveness

How the BRAF V600E mutation promotes the pathogenesis and aggressiveness of papillary thyroid cancer (PTC) is not completely understood. Here we explored a novel mechanism involving WASP interacting protein family member 1 (WIPF1). In PTC tumors, compared with the wild-type BRAF, BRAF V600E was associated with over-expression and hypomethylation of the WIPF1 gene. In thyroid cancer cell lines with wild-type BRAF, WIPF1 expression was robustly upregulated upon introduced expression of BRAF V600E (P=0.03) whereas the opposite was seen upon BRAF knockdown or treatment with BRAF V600E or MEK inhibitors in cells harboring BRAF V600E. Methylation of a functionally critical region of the WIPF1 promoter was decreased by expressing BRAF V600E in cells harboring the wild-type BRAF and increased by BRAF knockdown or treatment with BRAF V600E or MEK inhibitors in cells harboring BRAF V600E mutation. Under-expression and hypermethylation of WIPF1 induced by stable BRAF knockdown was reversed by DNA demethylating agent 5′-azadeoxycytidine. Knockdown of WIPF1 robustly inhibited anchorage-independent colony formation, migration, and invasion of thyroid cancer cells and suppressed xenograft thyroid cancer tumor growth and vascular invasion, mimicking the effects of BRAF knockdown. In human PTC tumors, WIPF1 expression was associated with extrathyroidal invasion (P=0.01) and lymph node metastasis (P=2.64E-05). In summary, BRAF V600E-activated MAP kinase pathway causes hypomethylation and overexpression of WIPF1; WIPF1 then functions like an oncoprotein to robustly promote aggressive cellular and tumor behaviors of PTC. This represents a novel mechanism in BRAF V600E-promoted PTC aggressiveness and identifies WIPF1 as a novel therapeutic target for thyroid cancer.

Differentiation of the Follicular Variant of Papillary Thyroid Carcinoma From Classic Papillary Thyroid Carcinoma: An Ultrasound Analysis and Complement to Fine-Needle Aspiration Cytology

OBJECTIVES

It is difficult to establish a diagnosis of the follicular variant of papillary thyroid carcinoma (PTC) using fine-needle aspiration cytology (FNAC). Preoperative features on ultrasound (US) imaging are different between follicular PTC and classic PTC. This study developed a risk score system to differentiate follicular PTC from classic PTC and to correlate the risk score of follicular PTC with its FNAC categories and pathologic features.

METHODS

The US features, FNAC results, and pathologic reports of 156 follicular PTC nodules and 152 classic PTC nodules from 296 patients with PTC along with their clinical characteristics were reviewed retrospectively. A risk score system based on US features was developed by multivariate logistic regression to differentiate classic PTC from follicular PTC nodules. The risk scores were then correlated with the FNAC category and pathologic features of the nodules.

RESULTS

The US risk score (5 × echogenicity + 3 × calcifications + 3 × marginal regularity) had an area under the receiver operating characteristic curve of 0.85 and a cutoff value of 8.0, with specificity of 87% and sensitivity of 69% for predicting a classic PTC nodule. The follicular PTC nodules with low Bethesda categorization (I-III) had a median US risk score of 6 (range, 0-11), which was higher than that of nodules with high categorization (IV-VI; median, 3; range, 0-11).

CONCLUSIONS

The US risk score may be useful in differentiating classic PTC from follicular PTC and complementary to FNAC in identifying follicular PTC.

Clinical Characteristics of Subtypes of Follicular Variant Papillary Thyroid Carcinoma

BACKGROUND

Among follicular variant papillary thyroid carcinomas (FVPTCs), the noninvasive encapsulated subtype has an excellent prognosis. For this reason, reclassification of noninvasive encapsulated FVPTC (EFVPTC) as a new entity called "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP) has been proposed, but controversy remains. To characterize noninvasive EFVPTC in an Asian population, the clinicopathologic features of each FVPTC subtype were compared in a Korean population.

METHODS

FVPTC patients (n = 142) who underwent thyroidectomy between 2009 and 2014, and whose tumor size was >1 cm, were included in the study. The surgical pathology of each patient was reevaluated by two independent expert pathologists.

RESULTS

The percentages of noninvasive and invasive EFVPTC and infiltrative FVPTC (IFVPTC) in the study were 30%, 31%, and 39%, respectively. There was no difference in preoperative cytological diagnosis or the extent of surgery between noninvasive and invasive EFVPTC. However, the proportion of Bethesda category IV was lower in IFVPTC (16%) than in noninvasive and invasive EFVPTC (35% and 36%, respectively). Therefore, thyroid lobectomy was more common in noninvasive or invasive EFVPTC (54% or 48%, respectively) than in IFVPTC (16%). Noninvasive EFVPTC showed lower multiplicity, extrathyroidal extension, and BRAF^V600E mutation frequency (three cases; 8%) than did invasive EFVPTC, but other pathological characteristics were similar. However, IFVPTC showed significant differences in tumor size, extrathyroidal extension, lymph node metastasis, Tumor Node Metastasis stage, and American Thyroid Association high-risk category compared with noninvasive and invasive EFVPTC. In the noninvasive EFVPTC group, there were six (14%) cases with multifocality and three (7%) cases with lymph node metastasis. However, only two cases with multifocality and one case with lymph node metastasis originated from noninvasive FVPTC, while the other cases were from coexisting conventional PTCs.

CONCLUSIONS

Noninvasive EFVPTC has favorable pathological features, but lymph node metastasis or BRAF^V600E mutations were observed in some patients. Therefore, in order for the distinction between noninvasive EFVPTC and invasive EFVPTC to have more clinical significance, the criteria for NIFTP need to be more strictly revised.

Association between preoperative thyrotrophin and clinicopathological and aggressive features of papillary thyroid cancer

PURPOSE

We aimed to investigate the relation between preoperative serum thyrotrophin (TSH) and clinicopathological features in patients with papillary thyroid carcinoma (PTC) and microcarcinoma (PTMC).

METHODS

Patients who underwent thyroidectomy and diagnosed to have benign nodular disease or PTC/PTMC in our clinic were evaluated retrospectively. Patients with a previous history of thyroid surgery, patients using antithyroid medications or thyroid hormone and patients with tumors known to be unresponsive to TSH were excluded.

RESULTS

Data of 1632 patients were analyzed. Histopathological diagnosis was benign in 969 (59.4%) and malignant in 663 (40.6%) patients. Preoperative median serum TSH was significantly higher in malignant compared to benign group (1.41 IU/dL vs. 0.98 IU/dL, p < 0.001). Malignancy risk increased gradually as going from hyperthyroidism to euthyroidism and hypothyroidism (20, 40.6, and 59.1%, respectively, p < 0.05). Serum TSH was lowest in benign nodular disease, higher in PTMC and highest in PTC (p < 0.001). This was also true when patients with positive antithyroid peroxidase/antithyroglobulin and with lymphocytic thyroiditis were excluded from the analysis (p < 0.001). Serum TSH was higher in patients with bilateral tumor, capsular invasion and lymph node metastasis (LNM) compared to patients with unilateral tumor, without capsule invasion and without LNM, respectively (p = 0.036, p = 0.002, and p = 0.001, respectively). Patients with aggressive variant PTC had higher serum TSH than nonaggressive ones (p < 0.05).

CONCLUSION

Preoperative serum TSH is associated with PTMC, PTC and LNM. Serum TSH seems to be related with thyroid cancer regardless of autoimmunity. With the present study, for the first time, we showed an association between serum TSH and aggressive variants of PTC.

A comparison of the clinicopathological features and prognoses of the classical and the tall cell variant of papillary thyroid cancer: a meta-analysis

Papillary thyroid cancer (PTC) accounts for 80–90% of all thyroid malignancies. The tall cell variant (TCV) is a rare aggressive histotype of PTC. We performed a meta-analysis to compare the clinicopathological characteristics and prognostic factors of TCV with those of classical papillary thyroid carcinoma (cPTC). A literature search was performed using the PubMed and EMBASE databases using Medical Subject Headings and keywords. Twenty studies that included 1871 patients with TCV and 75323 patients with cPTC were included in our meta-analysis. Odds ratios and confidence intervals were calculated for each study. Patients with TCV were associated with multifocality, higher TNM stage, extrathyroidal extension, vascular invasion, lymph node metastasis, distant metastasis, BRAF mutation, disease-specific survival, and overall survival. We found that TCV cases were associated with more aggressive clinicopathological characteristics and poorer prognoses than cPTC cases were. Our results suggest that TCV is a high-risk PTC that warrants aggressive treatment and follow-up strategies.

Thyroid lobectomy is not sufficient for T2 papillary thyroid cancers

BACKGROUND

Histologic subtypes of papillary thyroid cancer affect prognosis. The objective of this study was to examine whether survival is affected by extent of surgery for conventional versus follicular-variant papillary thyroid cancer when stratified by tumor size.

METHODS

Using the National Cancer Data Base, we evaluated 33,816 adults undergoing surgery for papillary thyroid cancer from 2004 to 2008 for 1.0-3.9 cm tumors and clinically negative lymph nodes. Conventional and follicular-variant papillary thyroid cancers were divided into separate groups. Cox regression models stratified by tumor size were used to determine if extent of surgery affected overall survival.

RESULTS

A total of 30,981 patients had total thyroidectomy and 2,835 had thyroid lobectomy; 22,899 patients had conventional papillary thyroid cancer and 10,918 had follicular-variant papillary thyroid cancer. On unadjusted KM analysis, total thyroidectomy was associated with improved survival for conventional (P = 0.02) but not for follicular-variant papillary thyroid cancer patients (P = 0.42). For conventional papillary thyroid cancer, adjusted analysis showed total thyroidectomy was associated with improved survival for 2.0-3.9 cm tumors (P = 0.03) but not for 1.0-1.9 cm tumors (P = 0.16). For follicular-variant, lobectomy and total thyroidectomy had equivalent survival for 1.0-1.9 cm (P = 0.45) and 2.0-3.9 cm (P = 0.88) tumors.

CONCLUSION

Tumor size, histologic subtype, and surgical therapy are important factors in papillary thyroid cancer survival. Total thyroidectomy was associated with improved survival in patients with 2.0-3.9 cm conventional papillary thyroid cancer, and should be considered for 2.0-3.9 cm papillary thyroid cancers when preoperative molecular analysis is not used to distinguish conventional from follicular-variant.

Patient Age-Associated Mortality Risk Is Differentiated by BRAF V600E Status in Papillary Thyroid Cancer

Purpose For the past 65 years, patient age at diagnosis has been widely used as a major mortality risk factor in the risk stratification of papillary thyroid cancer (PTC), but whether this is generally applicable, particularly in patients with different BRAF genetic backgrounds, is unclear. The current study was designed to test whether patient age at diagnosis is a major mortality risk factor. Patients and Methods We conducted a comparative study of the relationship between patient age at diagnosis and PTC-specific mortality with respect to BRAF status in 2,638 patients (623 men and 2,015 women) with a median age of 46 years (interquartile range, 35 to 58 years) at diagnosis and a median follow-up time of 58 months (interquartile range, 26 to 107 months). Eleven medical centers from six countries participated in this study. Results There was a linear association between patient age and mortality in patients with BRAF V600E mutation, but not in patients with wild-type BRAF, in whom the mortality rate remained low and flat with increasing age. Kaplan-Meier survival curves rapidly declined with increasing age in patients with BRAF V600E mutation but did not decline in patients with wild-type BRAF, even beyond age 75 years. The association between mortality and age in patients with BRAF V600E was independent of clinicopathologic risk factors. Similar results were observed when only patients with the conventional variant of PTC were analyzed. Conclusion The long-observed age-associated mortality risk in PTC is dependent on BRAF status; age is a strong, continuous, and independent mortality risk factor in patients with BRAF V600E mutation but not in patients with wild-type BRAF. These results question the conventional general use of patient age as a high-risk factor in PTC and call for differentiation between patients with BRAF V600E and wild-type BRAF when applying age to risk stratification and management of PTC.

Diagnostic significance of CK19, galectin-3, CD56, TPO and Ki67 expression and BRAF mutation in papillary thyroid carcinoma

The aim of the present study was to examine the rate of BRAF mutation and the expression profiles of CK19, galectin-3, CD56, thyroid peroxidase (TPO) and Ki67 in papillary thyroid carcinoma (PTC) and papillary thyroid micro-carcinoma (PTMC). A total of 246 cases of thyroid disease were collected, including PTC, PTMC, nodular goiter (NG) and Hashimoto thyroiditis (HT). The results revealed that CK19 expression was 116/120 in PTC, 61/64 in PTMC, 2/34 in NG and 1/28 in HT. Galectin-3 positive expression was 115/120 in PTC, 60/64 in PTMC, 6/34 in NG and 4/28 in HT. TPO positive expression was 8/120 in PTC, 1/64 in PTMC, 30/34 in NG and 25/28 in HT. CD56-positive expression was 12/120 in PTC, 3/64 in PTMC, 33/34 in NG and 26/28 in HT. Ki67 labeling index was 2.52±0.46% in PTC (120 cases), 2.62±0.52% in PTMC (64 cases), 2.55±0.44% in NG (34 cases) and 2.58±0.48% in HT (28 cases). BRAF mutation rate was 93/120 in PTC, 47/64 in PTMC, 3/34 in NG and 2/28 in HT. These results suggested that expression patterns of CK19, galectin-3, CD56 and TPO and BRAF mutation exhibit diagnosis value in thyroid disease. However, Ki67-positive rate exhibits no notable diagnosis value in thyroid disease.

High-throughput drug library screening identifies colchicine as a thyroid cancer inhibitor

We employed a high-throughput drug library screening platform to identify novel agents affecting thyroid cancer cells. We used human thyroid cancer cell lines to screen a collection of approximately 5200 small molecules with biological and/or pharmacologial properties. Parallel primary screens yielded a number of hits differentially active between thyroid and melanoma cells. Amongst compounds specifically targeting thyroid cancer cells, colchicine emerged as an effective candidate. Colchicine inhibited cell growth which correlated with G2 cell cycle arrest and apoptosis. These effects were hampered through inhibition of MEK1/2 and JNK. In contrast, inhibition of p38-MAPK had little effect, and AKT had no impact on colchicine action. Systemic colchicine inhibited thyroid cancer progression in xenografted mice. These findings demonstrate that our screening platform is an effective vehicle for drug reposition and show that colchicine warrants further attention in well-defined clinical niches such as thyroid cancer.

Histogram analysis of greyscale sonograms to differentiate between the subtypes of follicular variant of papillary thyroid cancer

AIM

To evaluate the diagnostic value of histogram analysis using ultrasound (US) to differentiate between the subtypes of follicular variant of papillary thyroid carcinoma (FVPTC).

MATERIALS AND METHODS

The present study included 151 patients with surgically confirmed FVPTC diagnosed between January 2014 and May 2016. Their preoperative US features were reviewed retrospectively. Histogram parameters (mean, maximum, minimum, range, root mean square, skewness, kurtosis, energy, entropy, and correlation) were obtained for each nodule.

RESULTS

The 152 nodules in 151 patients comprised 48 non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTPs; 31.6%), 60 invasive encapsulated FVPTCs (EFVPTCs; 39.5%), and 44 infiltrative FVPTCs (28.9%). The US features differed significantly between the subtypes of FVPTC. Discrimination was achieved between NIFTPs and infiltrative FVPTC, and between invasive EFVPTC and infiltrative FVPTC using histogram parameters; however, the parameters were not significantly different between NIFTP and invasive EFVPTC.

CONCLUSION

It is feasible to use greyscale histogram analysis to differentiate between NIFTP and infiltrative FVPTC, but not between NIFTP and invasive EFVPTC. Histograms can be used as a supplementary tool to differentiate the subtypes of FVPTC.

Molecular pathology of thyroid tumours of follicular cells: a review of genetic alterations and their clinicopathological relevance

Thyroid cancer is the most common endocrine malignancy. Knowledge of the molecular pathology of thyroid tumours originating from follicular cells has greatly advanced in the past several years. Common molecular alterations, such as BRAF p.V600E, RAS point mutations, and fusion oncogenes (RET-PTC being the prototypical example), have been, respectively, associated with conventional papillary carcinoma, follicular-patterned tumours (follicular adenoma, follicular carcinoma, and the follicular variant of papillary carcinoma/non-invasive follicular thyroid neoplasm with papillary-like nuclear features), and with papillary carcinomas from young patients and arising after exposure to ionising radiation, respectively. The remarkable correlation between genotype and phenotype shows how specific, mutually exclusive molecular changes can promote tumour development and initiate a multistep tumorigenic process that is characterised by aberrant activation of mitogen-activated protein kinase and phosphoinositide 3-kinase-PTEN-AKT signalling. Molecular alterations are becoming useful biomarkers for diagnosis and risk stratification, and as potential treatment targets for aggressive forms of thyroid carcinoma. What follows is a review of the principal genetic alterations of thyroid tumours originating from follicular cells and of their clinicopathological relevance.

MicroRNA-139 targets fibronectin 1 to inhibit papillary thyroid carcinoma progression

Thyroid cancer is the most common tumour of the endocrine system, and its incidence rate has markedly increased over the past several decades. Aberrantly expressed microRNAs (miRNAs) are reportedly involved in the formation and progression of papillary thyroid carcinoma (PTC) by regulating their target genes. Thus, miRNAs may be potential molecular biomarkers for the prediction and prognosis of PTC, and also as novel therapeutic targets for patients with PTC. miR-139 has recently been reported to be aberrantly expressed in several types of cancer. However, the expression levels, biological functions and the associated molecular mechanism of miR-139 in PTC have not been clearly elucidated. The results of the present study revealed that miR-139 expression was downregulated in PTC tissues and cell lines when compared with adjacent normal tissues and normal human thyroid cells, respectively. The restoration of miR-139 expression suppressed cellular proliferation and invasion in PTC in vitro. In addition, fibronectin 1 (FN1) was identified as a direct target of miR-139 in PTC. Furthermore, FN1 was highly expressed in PTC tissues and negatively associated with miR-139 expression. Moreover, the tumour-suppressive effects of miR-139 overexpression on PTC cells were ameliorated by ectopic FN1 expression. To the best of our knowledge, the present study is the first to demonstrate that miR-139 may serve as a tumour suppressor and serve important roles in inhibiting tumourigenesis by targeting FN1 in PTC cells.

Identification of Two Distinct Molecular Subtypes of Non-Invasive Follicular Neoplasm with Papillary-Like Nuclear Features by Digital RNA Counting

BACKGROUND

The follicular variant (FV) of papillary thyroid cancer (PTC) is one of the most common variants of PTC. Clinically, non-infiltrative FVPTC is considered a low-risk variant of PTC, and the non-invasive encapsulated forms of FVPTC represent a group of thyroid tumors with a particularly good prognosis. Consequently, these neoplasms have been very recently reclassified as non-invasive follicular neoplasms with papillary-like nuclear features (NIFTP). From a molecular standpoint, NIFTP appears to be similar to follicular neoplasms. However, only limited data are currently available regarding their gene expression profile.

METHODS

The aim of this study was to identify specific molecular signatures of 26 NIFTPs compared to those of 19 follicular adenomas (FAs) and 18 infiltrative FVPTCs (IFVPTCs). A nanoString custom assay was used to perform mRNA expression analysis. All cases were also genotyped for BRAF, N-, H-, and K-RAS mutations. Samples were grouped on the basis of gene expression profiles by Pearson's correlation and non-negative matrix factorization clustering analysis. Finally, the uncorrelated shrunken centroid machine-learning algorithm was used to classify the samples.

RESULTS

The results revealed distinct expression profiles of FAs and IFVPTCs. NIFTP samples can exhibit different expression profiles, more similar to FAs (FA-like) or to IFVPTCs (IFVPTC-like), and these different expression profiles largely depend on the presence of different mutations (RAS or BRAF).

CONCLUSION

In conclusion, although further validation of the model is required by using a larger group of prospective cases, these data reinforce the hypothesis that IFVPTC-like NIFTPs might represent precursors of IFVPTC.

Reevaluating the prognostic significance of male gender for papillary thyroid carcinoma and microcarcinoma: a SEER database analysis

The prognostic significance of gender remains controversial for papillary thyroid carcinoma (PTC). In this study, we investigated the associations between gender and prognosis in a large cohort of patients with PTC or PTMC that was diagnosed in 2010–2013 and recorded in the Surveillance, Epidemiology, and End Results cancer registry. The mean ± standard deviation duration of survival for all patients with PTC during the study period was 21.47 ± 14.04 months. In Kaplan-Meier analyses of the entire cohort of PTC patients, survival curves for all-cause death and cancer-specific death declined more sharply for men than for women. Similar results were observed in analyses of patients with PTCs > 1 cm and PTMC. After adjusting for potential confounders, hazard rates indicated significantly elevated all-cause mortality for men in analyses of all PTCs, PTCs > 1 cm, and PTMCs. However, in a confounder-adjusted analysis of patients with PTMC, the hazard rate did not indicate significantly higher mortality for men than for women. Our study demonstrated that male gender is an independent poor prognostic factor for all PTCs and for PTCs > 1 cm. However, gender is not an independent prognostic factor for cause-specific survival in PTMC.

The Prognostic Value of Tumor Multifocality in Clinical Outcomes of Papillary Thyroid Cancer

CONTEXT

Multifocality is often treated as a risk factor for papillary thyroid cancer (PTC), prompting aggressive treatments, but its prognostic value remains unestablished.

OBJECTIVE

To investigate the role of tumor multifocality in clinical outcomes of PTC.

METHODS

Multicenter study of the relationship between multifocality and clinical outcomes of PTC in 2638 patients (623 men and 2015 women) with median [interquartile range (IQR)] age of 46 (35 to 58) years and median (IQR) follow-up time of 58 (26 to 107) months at 11 medical centers in six countries. Surveillance, Epidemiology and End Results (SEER) data were used for validation.

RESULTS

Disease recurrence in multifocal and unifocal PTC was 198 of 1000 (19.8%) and 221 of 1624 (13.6%) (P < 0.001), with a hazard ratio of 1.55 [95% confidence interval (CI), 1.28 to 1.88], which became insignificant at 1.13 (95% CI, 0.93 to 1.37) on multivariate adjustment. Similar results were obtained in PTC variants: conventional PTC, follicular-variant PTC, tall-cell PTC, and papillary thyroid microcarcinoma. There was no association between multifocality and mortality in any of these PTC settings, whereas there was a strong association between classic risk factors and cancer recurrence or mortality, which remained significant after multivariate adjustment. In 1423 patients with intrathyroidal PTC, disease recurrence was 20 of 455 (4.4%) and 41 of 967 (4.2%) (P = 0.892) and mortality was 0 of 455 (0.0%) and 3 of 967 (0.3%) (P = 0.556) in multifocal and unifocal PTC, respectively. The results were reproduced in 89,680 patients with PTC in the SEER database.

CONCLUSIONS

Tumor multifocality has no independent risk prognostic value in clinical outcomes of PTC; its indiscriminate use as an independent risk factor, prompting overtreatments of patients, should be avoided.

Follicular morphological characteristics may be associated with invasion in follicular thyroid neoplasms with papillary-like nuclear features

The newly proposed nomenclature and diagnostic criteria for encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC), the noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP), could improve the consistency and accuracy of diagnosing this entity. Diagnosis of NIFTP requires evaluation of the complete tumor border or capsule. The presence of tumor invasion in follicular thyroid neoplasms with papillary-like nuclear features has been recently discussed by many authors. In this study, we examined the predictive value and association of follicular morphological characteristics with the tumor invasion. In addition, we analyzed the association between tumor encapsulation and molecular profile in EFVPTC/NIFTP cases. A total of 106 cases of FVPTC were included in the study. The tumors were grouped based on the presence of tumor capsule and characteristics of tumor border, as 1) completely encapsulated tumors without invasion, 2) encapsulated tumors with invasion, 3) infiltrative tumors without a capsule. Clinicopathological features, histomorphological features [nuclear criteria, minor diagnostic features, follicles oriented perpendicular to tumor border/capsule (FOPBC)] and molecular alterations in BRAF, NRAS, and KRAS genes were evaluated. FOPBC were significantly more frequently seen in encapsulated tumors with invasion (p = 0.008). The nuclear features were not associated with the presence of encapsulation and characteristics of tumor border. BRAF mutation was more frequent in infiltrative tumors, while NRAS mutation was more frequent in encapsulated tumors, but the results were not statistically significant (p = 0.917). In conclusion, FOPBC histomorphological feature may be associated with tumor invasion in EFVPTC/NIFTP. Additionally, BRAF/KRAS/NRAS mutation analysis may prevent inadequate treatment in these patients.

Defining Papillary Carcinoma of the Thyroid: A Short Review and Analysis

OBJECTIVES

To review how changes in the pathologic definitions for papillary tumors of the thyroid during recent decades have affected outcomes for patients with these tumors.

METHODS

Forty-nine previous reports or studies involving collectively 53,606 patients were reviewed, and new analyses were performed on the data to include analyses of agreement, incidence, survival, and diagnostic categories.

RESULTS

The past emphasis on cytologic features to define papillary tumors has not resulted in ideal pairwise agreement between pathologists and has produced incidence and survival data suggesting overdetection and overdiagnosis. Most recently, tissue patterns have been reemphasized.

CONCLUSIONS

With the recent reemphasis on diagnostic tissue patterns (over cytologic criteria), agreements between pathologists for the diagnosis of papillary tumors should improve, and the incidence of papillary carcinoma should decline. Nevertheless, updated survival analyses demonstrate excellent long-term survival for most of those diagnosed with papillary carcinomas.

Impact of major different variants of papillary thyroid microcarcinoma on the clinicopathological characteristics: the study of 1041 cases

Background

The incidence of papillary thyroid microcarcinoma (PTMC) has been increasing globally in the past few decades. PTMC does not have a distinctive morphology that results in differences in biological behavior. The aim of this study was to classify PTMCs according to the morphological features and explore the relationship with clinicopathological characteristics. Additionally, we sought to evaluate whether different variants of PTMC can be an independent predictor for lymph mode metastasis when considering other risk factors.

Methods

Between December 2014 and December 2015, 1041 PTMC cases undergoing surgical resection at Tianjin Medical University Cancer Institute and Hospital were reviewed retrospectively. Statistical analysis was performed to investigate the independent factors for lymph node metastasis in PTMC.

Results

Conventional variant PTMC (CPTMC), follicular variant PTMC (FPTMC), and encapsulated variant PTMC (EnPTMC) were major variants in PTMC, collectively accounting for 96.7% of the entire PTMC cohort.There were significant differences in clinicopathological characteristics among the three major variants. The frequency of aggressive parameters was significantly different among the three variants, including tumor size, minimal extrathyroidal extension (minimal ETE), and lymph node metastasis (all P < 0.05), being highest in CPTMC, lowest in EnPTMC, and intermediate in FPTMC. FPTMC (OR = 0.642, P = 0.003) and EnPTMC (OR = 0.540, P = 0.041) were independent protective factors for lymph node metastasis (LNM). In contrast, male gender (OR = 1.836, P = 0.000), age less than 45 years (OR = 1.457, P = 0.009), tumor size greater than 0.5 cm (OR = 1.453, P = 0.007), calcification (OR = 1.465, P = 0.016), minimal ETE (OR = 1.801, P = 0.001), and multifocality (OR = 1.721, P = 0.000) were independent risk factors for LNM.

Conclusions

The present study demonstrates the distinct biological behaviors of the three major PTMC variants and establishes an aggressive order of CPTMC ≫ FPTMC > EnPTMC. It is necessary to take into consideration variant-related risks and other independent predictors for the determination of lymphadenectomy in patients with PTMC.

Association between BRAF V600E Mutation and Ultrasound Features in Papillary Thyroid Carcinoma Patients with and without Hashimoto's Thyroiditis

To assess the association between BRAF V600E mutation and ultrasound (US) features in papillary thyroid carcinoma (PTC) patients with and without Hashimoto’s thyroiditis (HT). We retrospectively reviewed the US features and status of BRAF V600E mutation in 438 consecutive patients with surgically confirmed PTCs. The association between BRAF mutation and US features were analyzed. In addition, we conducted subgroup analyses in terms of coexistent HT. The BRAF mutation was found in 86.5% of patients (379 of 438). Patient age (OR: 1.028, P = 0.010), age ≥ 50 y (OR: 1.904, P = 0.030), and microcalcification (OR: 2.262, P = 0.015) on US were significantly associated with BRAF mutation in PTC patients. Solid component (OR: 5.739, P = 0.019) on US was the significant predictor for BRAF mutation in patients with HT, while age (OR: 1.036, P = 0.017) and microcalcification (OR: 3.093, P = 0.017) were significantly associated with BRAF mutation in patients without HT. In conclusion, older age and microcalcification are risk factors for BRAF mutation in PTC patients, especially in those without HT. For those with HT, however, PTCs with BRAF mutation tend to be solid on ultrasound. These factors might be considered when making treatment planning or prognosis evaluation.

Predictive Factors of Lymph Node Metastasis in Follicular Variant of Papillary Thyroid Carcinoma

BACKGROUND

Compared with conventional papillary thyroid carcinoma (PTC), follicular variant of PTC (FV-PTC) shows less aggressive behavior and better prognosis. Nonetheless, regional lymph node (LN) metastasis was found in 22.8% of FV-PTC patients. Because LN metastasis is a proven predictor of recurrence in PTC, it is important to assess LN metastasis in FV-PTC patients.

METHODS

We retrospectively reviewed 134 FV-PTC patients who underwent thyroidectomy with neck dissection.

RESULTS

Central LN metastasis (CLNM) and lateral LN metastasis (LLNM) were found in 50 (37.3%) and 16 (11.9%) patients, respectively. In the multivariate analysis for CLNM, male sex (adjusted OR 4.735, p = 0.001), nonencapsulated form (adjusted OR 2.863, p = 0.022), and tumor size >1.0 cm (adjusted OR 3.157, p = 0.008) were independent predictors of high prevalence of CLNM in FV-PTC patients. In the multivariate analysis for LLNM, microscopic extrathyroidal extension (ETE) (adjusted OR 3.939, p = 0.041) and CLNM (adjusted OR 13.340, p = 0.001) were independent predictors of high prevalence of LLNM in FV-PTC patients.

CONCLUSIONS

Meticulous perioperative evaluation and prophylactic central neck dissection may be beneficial for FV-PTC patients with male sex, nonencapsulated form, and tumor size >1.0 cm. Moreover, cautious perioperative evaluation of lateral neck LN may be mandatory for FV-PTC patients with microscopic ETE and CLNM.

Noninvasive Follicular Thyroid Neoplasm with Papillary-Like Nuclear Features: Historical Context, Diagnosis, and Future Challenges

The encapsulated/well-demarcated non-invasive form of follicular variant of papillary thyroid carcinoma (FVPTC) that occurs annually in 45,000 patients worldwide was thought for 30 years to be a carcinoma. Many studies have now shown almost no recurrence in these non-invasive tumors, even in patients treated by surgery without radioactive iodine therapy. The categorization of the tumor as cancer has led to aggressive forms of treatment, with their side effects, financial costs, and the psychological and social impact of a cancer diagnosis. Recently, the encapsulated/well-demarcated non-invasive, FVPTC was renamed as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) by an international group of experts. The new terminology lacks the carcinoma label enabling clinicians to avoid aggressive therapy. By taking the reader through the history of FVPTC, this article explains how diagnostic criteria for thyroid carcinoma of follicular cells have evolved over the last 60 years. It discusses the steps that led to the labeling of FVPTC as cancer and highlights the various studies that helped reclassify and rename this tumor. It also sheds light on the impact of this reclassification on cytologic diagnosis and focuses on the studies needed to refine and expand the histologic criteria of NIFTP. By understanding the history of this change in nomenclature, future classification of tumors will be greatly improved.

The Treatment of Advanced Thyroid Cancer in the Age of Novel Targeted Therapies

Until recently, patients with advanced thyroid cancers had limited options for systemic treatment. With the introduction of tyrosine kinase inhibitors (TKIs) as a promising new class of targeted therapies for thyroid cancer, suddenly patients with advanced disease were given new options to extend survival. Guidelines worldwide have been updated to include general indications for these newer agents, but questions remain regarding which agent(s) to select, when to begin treatment, and how long therapy should continue. Additionally, the true impact of TKIs on overall survival and quality-of-life in thyroid cancer patients needs further clarification. As familiarity with approved agents and longer-term data become available, better strategies for implementation of these targeted drugs will evolve to optimize benefit for patients living with metastatic disease.

Impact of sex on the clinicopathological characteristics and prognosis of papillary thyroid cancer

SUMMARY

Papillary thyroid cancer (PTC) is the most common endocrine malignancy. Observed clinical and pathological differences between the sexes of PTC patients have been reported. There is currently no consensus regarding the impact of sex on PTC prognostication. We studied 566 PTC patients and observed that there was a higher PTC incidence in women, that PTC diagnosis was more challenging in women, and that men tended to present with larger cancers. However, once PTC is diagnosed, both sexes have a similar cancer prognosis, as evaluated using the MACIS (Metastasis, Age, Completeness of Resection, Invasion, Size) score. Our observations suggest that research efforts should be especially directed at improving the diagnostic yield of preoperative fine needle aspiration biopsy in women who present with nodular thyroid disease.

ZCCHC12, a novel oncogene in papillary thyroid cancer

PURPOSE

Thyroid cancer is the most common endocrine malignancy worldwide. The molecular mechanisms underlying thyroid tumorigenesis remain unclear. Some studies suggested that the ZCCHC12 gene correlates with certain diseases. However, the function of ZCCHC12 in thyroid cancer has yet to be determined. This study investigated the role of the ZCCHC12 gene in papillary thyroid cancer (PTC).

METHODS

We conducted a comprehensive analysis of massively parallel whole-transcriptome resequencing of matched PTC tumors and normal tissues in 19 patients. Results showed that the expression of ZCCHC12 was significantly upregulated in thyroid cancer. qRT-PCR was performed to confirm previous results. The functions of the ZCCHC12 gene in PTC cell lines (TPC1 and BCPAP) transfected with small interfering RNA were determined through cell colony formation assay, migration assay, and invasion assay.

RESULTS

The ZCCHC12 gene was remarkably upregulated in primary PTC tumors in both validated cohort (T:N = 1.80 ± 2.58:0.23 ± 0.50, P < 0.01) and TCGA cohort (T:N = 7.63 ± 3.25:1.55 ± 1.71, P < 0.01). We also achieved area under the curve (AUC of ROC) of 87.9% for the validated cohort while 91.4% for the TCGA cohort to classify PTC tumors and normal tissues. ZCCHC12 overexpression correlated with lymph node metastasis in both cohorts (P < 0.05). In in vitro experiments, ZCCHC12 downregulation significantly inhibited the colony formation, migration, and invasion of PTC cells.

CONCLUSION

Our study indicated that ZCCHC12 gene has important biological functions and acts as a metastasis-related oncogene in PTC.

MicroRNA-based molecular classification of papillary thyroid carcinoma

MicroRNA (miRNA) expression is dysregulated in many human malignancies, and a growing number of studies are focused on their potential use as tumor biomarkers. To identify a miRNA signature for papillary thyroid carcinomas (PTC), we investigated miRNA expression profiles in two independent cohorts of PTCs, which included major histological subtypes [classical-type (PTC‑CT), follicular-variant (PTC‑FV), and tall-cell variant (PTC‑TCV)] and cases with low or intermediate risk of recurrence. Using TaqMan® Array Human MicroRNA A+B Cards v3.0, we first performed microRNA profiling of normal and neoplastic thyroid tissues from 29 PTC patients. Promising candidates were then investigated in a second, independent cohort of 76 PTCs using Custom TaqMan® Array MicroRNA Cards. We identified a molecular signature of 11 miRNAs that were significantly upregulated (miR‑146b-5p, miR‑146b-3p, miR‑221-3p, miR‑222‑5p, miR‑222‑3p) or downregulated (miR‑1179, miR‑486‑5p, miR‑204-5p, miR‑7-2-3p, miR‑144-5p, miR‑140-3p) in PTC tissues vs. normal thyroid tissue. Upregulation of miR‑146b-5p and miR‑222‑3p was also significantly associated with an increased risk of recurrence. Higher than normal expression of miR‑146b-5p and miR‑146b-3p characterized PTC‑CT and PTC‑TCV but not PTC‑FV, whereas miR‑21-5p was significantly upregulated only in PTC‑TCV. When PTC‑FV were subclassified as encapsulated (PTC‑EFV) or infiltrative (PTC‑IFV), miR‑204-5p was downregulated in all histological subtypes except PTC‑EFV, which displayed expression levels similar to those of normal thyroid tissues. These findings provide new insights into the molecular classification of PTC, showing that different miRNA expression profiles are associated with different histological types of PTC and different risks of recurrence.

How do etiological factors can explain the different clinical features of patients with differentiated thyroid cancer and their histopathological findings?

The aim was to retrospectively analyse the clinical-histopathological characteristics of patients with newly diagnosis of differentiated thyroid cancer (DTC) referred to two Italian centres, one in Northern and the other in Southern Italy, between 2000 and 2013. 1081 patients were included and subdivided into two groups: group A (474 patients from Novara) and group B (607 patients from Naples). The group A came from the industrial area of Novara, while the Group B came from the areas around Vesuvius and Campi Flegrei. The two groups were comparable for iodine levels, body mass index, diagnostic timing and clinical procedures. For all patients, demographic and clinical data were collected. No difference was found in gender, whereas the age at diagnosis was later in the group A (group A 53.1 ± 15.16 years, group B 41.9 ± 14.25 years, p < 0.001). In both groups, the most frequent histotype was papillary thyroid cancer (PTC) with prevalence of follicular variant in group A (p < 0.0001) and classical variant in group B (p < 0.0001). Aggressive histological features were mainly seen in group A (bilaterality p < 0.0001, multifocality p < 0.0001 and thyroid capsular invasion p < 0.0001). Microcarcinomas were more frequent in group A (p < 0.0001) but mostly characterized by bilaterality (p < 0.001) and multifocality (p < 0.04). In both groups, tumour-associated thyroiditis showed a significant increase over the years (group A p < 0.05, group B p < 0.04). Environmental factors could justify the differences found in our study. These preliminary data should stimulate the need for an Italian Cancer Registry of DTC in order to allow an epidemiological characterization, allowing the identification of specific etiological factors and an improvement in the management of the disease.

Prognostic implication of histological features associated with EHD2 expression in papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is a heterogeneous tumor with various histological and molecular subtypes. EHD2 is involved in endocytosis and endosomal recycling. This study aimed to investigate the prognostic significance of EHD2 expression in PTC and develop a new model for predicting persistent/recurrent disease after thyroidectomy. Pathologic slides of 512 consecutive patients with PTC ≥ 1 cm were retrospectively reviewed. BRAF mutation analysis and immunohistochemistry for EHD2 were performed. Clinical significance of EHD2 mRNA expression was analyzed in 388 PTC patients using The Cancer Genome Atlas dataset. The presence of dyscohesive cells and psammoma bodies were found have significant association with persistent/recurrent disease (p = 0.049 and p = 0.038, respectively). The best discrimination of disease-free survival was found by dividing patients into three prognostic groups based on the following two risk factors according to the size category: psammoma bodies ≥ 4 and dyscohesive cells (≥ 1% and ≥ 20% in PTCs of < 2.0 cm and ≥ 2.0 cm, respectively). In PTCs of ≥ 2.0 cm, patients with the two risk factors had a hazard ratio of 13.303 (p = 0.005) compared to those without risk factors. High expression level of EHD2 was associated with BRAF V600E (p < 0.001), presence of dyscohesive cells (p = 0.010), and absence of psammoma bodies (p = 0.001). Increased EHD2 mRNA expression level was associated with extrathyroidal extension (p < 0.001), pT3-4 (p < 0.001), lymph node metastasis (p < 0.001), higher risk of recurrence (p < 0.001), and BRAF V600E (p < 0.001). Our prognostic model is useful for predicting persistent/recurrent disease after surgery of PTC. EHD2 mRNA expression could be a novel prognostic marker for PTC patients.

Aggressiveness of the tall cell variant of papillary thyroid carcinoma is independent of the tumor size and patient age

The tall cell variant (TCV) of papillary thyroid carcinoma (PTC) is characterized by tall columnar cells with a height of at least three times their width. TCV usually presents at an older age, has a larger size and exhibits more extrathyroidal extension and metastases than classical PTC. The current study compared TCV with the classical and follicular variants (CaFVs) of PTC to determine if, irrespective of the age at diagnosis and tumor size, TCV is more aggressive than its classical and follicular counterparts. A total of 16 (3.66%) patients with TCV were identified in a series of 437 patients with PTC from the Clinical University Hospital (Santiago de Compostela, Spain) between 1990 and 2010. The patient clinicopathological features and B-Raf proto-oncogene (BRAF)V600E mutational status were compared with 34 cases of CaFVs of PTC matched for tumor size and patient age. The TCV series included 11 females and 5 males aged 15–74 years (median, 57 years). In total, 15 (93.8%) patients underwent total or near-total thyroidectomy, 1 underwent lobectomy and 5 (31.3%) underwent lymph node dissection. In the TCV series, the tumor size ranged from 5–45 mm (median, 19 mm). Compared with the CaFVs, the TCV of PTC exhibited a significantly higher prevalence of extrathyroidal extension [9/16 (56.3%) vs. 5/34 (14.7%) cases; P=0.007], lymph node metastases [9/16 (56.3%) vs. 9/34 (26.4%) cases; P=0.04], stage III/IV at presentation [10/16 (62.5%) vs. 7/34 (20.5%) cases; P=0.009] and BRAFV600E mutation [12/16 (80.0%) vs. 7/25 (28.0%) cases; P=0.004]. The TCV series also harbored more multifocal papillary carcinomas (50.0% vs. 26.4%), lymphovascular invasion (37.5% vs. 29.4%) and distant metastases (6.2% vs. 0.0%), as compared with the matched patient cohort. In conclusion, the TCV of PTC is frequently associated with BRAFV600E mutation and is more aggressive than the CaFVs of PTC, regardless of tumor size and patient age at diagnosis.

Programmed Death - Ligand 1 Expression Distinguishes Invasive Encapsulated Follicular Variant of Papillary Thyroid Carcinoma from Noninvasive Follicular Thyroid Neoplasm with Papillary-like Nuclear Features

BACKGROUND

The noninvasive Encapsulated follicular variant of papillary thyroid cancer (EFVPTC) has been reclassified as Noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) without a significant risk for malignant behavior. However the evaluation remains a challenge for clinicians. We sought to determine whether programmed death-ligand 1 (PD-L1) expression may serve as a biomarker to predict invasiveness of EFVPTC and assist to distinguish these neoplasms from NIFTP.

METHODS

Immunohistochemical staining of PD-L1 expression was performed in sections of 174 Formalin-fixed paraffin-embedded (FFPE) tissue blocks from surgery removed thyroid nodules.

RESULTS

Cytoplasmic PD-L1 expression was significantly increased in invasive EFVPTC (4.76±1.49) as compared to NIFTP (3.06±2.16, p<0.001). Increased cytoplasmic PD-L1 expression was associated with invasiveness in EFVPTC (p<0.001); PD-L1 positive EFVPTC cases were at 3.16 folds higher risk in developing invasion than the PD-L1 negative cases. No significant difference in cytoplasmic PD-L1 expression was observed between NIFTP and benign nodules.

CONCLUSION

PD-L1 expression may serve as a useful biomarker in predicting invasiveness of EFVPTC and distinguishing NIFTP from invasive EFVPTC. To our knowledge this is the first report suggesting the application of a protein biomarker to confirm NIFTP as benign indolent neoplasms.

The evolution of differentiated thyroid cancer

Differentiated thyroid tumours of follicular cell derivation have traditionally been classified based on architecture, cytology, or both. The features that distinguish the various entities are controversial and diagnostic criteria are inconsistent and often irreproducible. The complexity of classification schemes has not been substantiated by molecular profiling. In this review, a simplistic approach to the diagnosis of well differentiated thyroid neoplasia is provided to challenge the dogma. The proposed classification matches the molecular profiles of these lesions and simplifies the criteria for diagnosis. This approach can be used to support rational treatment algorithms.

Update on the cytologic features of papillary thyroid carcinoma variants

Papillary thyroid cancer (PTC), which accounts for 85-90% of all thyroid cancers, is generally an indolent tumor with long term survival rates >95%. A reliable definitive diagnosis of PTC is usually straightforward in fine needle aspirates of conventional PTC whenever the characteristic papillary and/or flat honeycomb sheet-like architecture and the typical nuclear features of chromatin pallor, nuclear enlargement, crowding, grooves and pseudoinclusions are encountered. Conventional PTC, however, has diminished in relative frequency as compared to PTC variants, especially the noninvasive follicular variant of PTC, an indolent tumor which has recently been reclassified as "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP). These PTC variants are characterized by various architecture, cell type and shape, and stromal features, some of which can be recognized cytologically. Awareness of the cytomorphological spectrum and of the characteristic cytological features of these PTC variants is important to avoid diagnostic pitfalls. In this article, we review the different variants of PTC, including their cytomorphologic features, differential diagnosis, and salient molecular features. Diagn. Cytopathol. 2017;45:714-730. © 2017 Wiley Periodicals, Inc.

Nomenclature Revision for Encapsulated Follicular Variant of Papillary Thyroid Carcinoma: A Paradigm Shift to Reduce Overtreatment of Indolent Tumors

IMPORTANCE

Although growing evidence points to highly indolent behavior of encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC), most patients with EFVPTC are treated as having conventional thyroid cancer.

OBJECTIVE

To evaluate clinical outcomes, refine diagnostic criteria, and develop a nomenclature that appropriately reflects the biological and clinical characteristics of EFVPTC.

DESIGN, SETTING, AND PARTICIPANTS

International, multidisciplinary, retrospective study of patients with thyroid nodules diagnosed as EFVPTC, including 109 patients with noninvasive EFVPTC observed for 10 to 26 years and 101 patients with invasive EFVPTC observed for 1 to 18 years. Review of digitized histologic slides collected at 13 sites in 5 countries by 24 thyroid pathologists from 7 countries. A series of teleconferences and a face-to-face conference were used to establish consensus diagnostic criteria and develop new nomenclature.

MAIN OUTCOMES AND MEASURES

Frequency of adverse outcomes, including death from disease, distant or locoregional metastases, and structural or biochemical recurrence, in patients with noninvasive and invasive EFVPTC diagnosed on the basis of a set of reproducible histopathologic criteria.

RESULTS

Consensus diagnostic criteria for EFVPTC were developed by 24 thyroid pathologists. All of the 109 patients with noninvasive EFVPTC (67 treated with only lobectomy, none received radioactive iodine ablation) were alive with no evidence of disease at final follow-up (median [range], 13 [10-26] years). An adverse event was seen in 12 of 101 (12%) of the cases of invasive EFVPTC, including 5 patients developing distant metastases, 2 of whom died of disease. Based on the outcome information for noninvasive EFVPTC, the name "noninvasive follicular thyroid neoplasm with papillary-like nuclear features" (NIFTP) was adopted. A simplified diagnostic nuclear scoring scheme was developed and validated, yielding a sensitivity of 98.6% (95% CI, 96.3%-99.4%), specificity of 90.1% (95% CI, 86.0%-93.1%), and overall classification accuracy of 94.3% (95% CI, 92.1%-96.0%) for NIFTP.

CONCLUSIONS AND RELEVANCE

Thyroid tumors currently diagnosed as noninvasive EFVPTC have a very low risk of adverse outcome and should be termed NIFTP. This reclassification will affect a large population of patients worldwide and result in a significant reduction in psychological and clinical consequences associated with the diagnosis of cancer.

Is Male Gender a Prognostic Factor for Papillary Thyroid Microcarcinoma?

BACKGROUND

Male gender is a prognostic factor of poor outcome in papillary thyroid carcinoma (PTC). We investigated the prognostic role of male gender in papillary thyroid microcarcinoma (PTMC).

METHODS

We included 2930 patients who underwent surgery at Asan Medical Center for PTC. Clinicopathologic characteristics from the patients' medical records were compared for male and female PTC patients. Independent prognostic factors for recurrence in PTC and PTMC were evaluated after propensity score matching analysis. The median follow-up period was 82 months.

RESULTS

Recurrence and death were more common in male patients with PTC than in female patients with PTC (12.6 vs. 9.6%, p = 0.03 and 2.2 vs. 0.6%, p < 0.001, respectively). However, there was no difference in disease-free survival between male and female PTMC patients (p = 0.57). Multivariate analysis after propensity score matching revealed that male gender is not an independent prognostic factor of recurrence in PTMC (hazard ratio [HR] 1.5, 95% confidence interval 0.75-5.33, p = 0.17), but that it is an independent prognostic factor in PTC >1 cm (HR = 3.06, 95% confidence interval 1.34-6.98, p = 0.008).

CONCLUSIONS

Male gender is an independent prognostic factor for recurrence in PTC >1 cm, but it is not a prognostic factor in PTMC.

The History of the Follicular Variant of Papillary Thyroid Carcinoma

CONTEXT

This review provides historical context to recent developments in the classification of the follicular variant of papillary thyroid carcinoma (FVPTC). The evolution of the diagnostic criteria for papillary thyroid carcinoma is described, clarifying the role of molecular analysis and the impact on patient management.

METHODS

A PubMed search using the terms "follicular variant" and "papillary thyroid carcinoma" covering the years 1960 to 2016 was performed. Additional references were identified through review of the citations of the retrieved articles.

RESULTS

The encapsulated/well-demarcated, noninvasive form of FVPTC that occurs annually in 45,000 patients worldwide was thought for 30 years to be a carcinoma. Many studies have shown almost no recurrence in these noninvasive tumors, even in patients treated by surgery alone without radioactive iodine therapy. The categorization of the tumor as outright cancer has led to aggressive forms of treatment, with their side effects, financial costs, and the psychological and social impacts of a cancer diagnosis. Recently, the encapsulated/well-demarcated, noninvasive FVPTC was renamed as noninvasive follicular thyroid neoplasm with papillary-like nuclear features. The new terminology lacks the carcinoma label, enabling clinicians to avoid aggressive therapy.

CONCLUSIONS

By understanding the history of FVPTC, future classification of tumors will be greatly improved.

A six-genotype genetic prognostic model for papillary thyroid cancer

A unique prognostic role of the genetic duet of BRAF V600E and TERT promoter mutations in papillary thyroid cancer (PTC) has been recently established, but the role of RAS mutation in this genetic interplay remains to be established. Using The Cancer Genome Atlas (TCGA) data of patients with PTC from 19 medical centers, we investigated the interactions among the three mutations in clinical outcomes of PTC. We found that BRAF and RAS mutations were mutually exclusive, but both were associated with TERT promoter mutations, with the genetic duet of BRAF/RAS and TERT mutations occurring in 34/388 (8.76%) patients. BRAF/RAS or TERT mutation had no or minimal effect alone, whereas coexisting BRAF/RAS and TERT mutations had a robust synergistic effect on poor clinicopathologic outcomes of PTC, including disease recurrence and patient mortality. For example, PTC recurrence rate was 52% with coexisting BRAF V600E/RAS and TERT promoter mutations vs 6.9% with no mutation, corresponding to a HR of 8.17 (95% CI 3.09-21.58), which remained significant at 14.71 (95% CI 2.79-77.61) after adjustment for clinicopathologic factors and institution. BRAF/RAS mutation or TERT mutation alone minimally affected Kaplan-Meier patient survival curves, whereas the genetic duet was associated with a sharp curve decline. Thus, by confirming and expanding previous findings in single-institution studies, this multicenter data analysis establishes a six-genotype genetic prognostic model for poor outcomes of PTC with a risk order of genetic duet of BRAF V600E/RAS mutation and TERT mutation >>>>BRAF V600E = TERT mutation alone >RAS mutation alone = wild-type genes.

Defective ciliogenesis in thyroid hürthle cell tumors is associated with increased autophagy

Primary cilia are found in the apical membrane of thyrocytes, where they may play a role in the maintenance of follicular homeostasis. In this study, we examined the distribution of primary cilia in the human thyroid cancer to address the involvement of abnormal ciliogenesis in different thyroid cancers. We examined 92 human thyroid tissues, including nodular hyperplasia, Hashimoto's thyroiditis, follicular tumor, Hürthle cell tumor, and papillary carcinoma to observe the distribution of primary cilia. The distribution and length of primary cilia facing the follicular lumen were uniform across variable-sized follicles in the normal thyroid gland. However, most Hürthle cells found in benign and malignant thyroid diseases were devoid of primary cilia. Conventional variant of papillary carcinoma (PTC) displayed longer primary cilia than those of healthy tissue, whereas both the frequency and length of primary cilia were decreased in oncocytic variant of PTC. In addition, ciliogenesis was markedly defective in primary Hürthle cell tumors, including Hürthle cell adenomas and carcinomas, which showed higher level of autophagosome biogenesis. Remarkably, inhibition of autophagosome formation by Atg5 silencing or treatment with pharmacological inhibitors of autophagosome formation restored ciliogenesis in the Hürthle cell carcinoma cell line XTC.UC1 which exhibits a high basal autophagic flux. Moreover, the inhibition of autophagy promoted the accumulation of two factors critical for ciliogenesis, IFT88 and ARL13B. These results suggest that abnormal ciliogenesis, a common feature of Hürthle cells in diseased thyroid glands, is associated with increased basal autophagy.

MiR-639 promoted cell proliferation and cell cycle in human thyroid cancer by suppressing CDKN1A expression

Accumulating evidence has indicated that aberrantly expressed microRNAs (miRs) are extensively involved in cancer development and progression. MiR-639 has been reported to act as tumor promoter in various types of cancer. However, the biological function and underlying molecular mechanism of miR-639 in thyroid carcinoma (TC) have not been intensively investigated. Herein the present study aimed to investigate the functional role of miR-639 in TC. We found that miR-639 expression was upregulated in TC cells and clinical tissues. Overexpression of miR-639 promoted TC cell proliferation and cell cycle, with increased expression of CyclinE and c-myc, whereas miR-639-in reverses the function. Using prediction software and luciferase reporter assay, we found that CDKN1A was a target of miR-639. CDKN1A small interfering RNA (siRNA) abrogated the role of miR-639-in on cell proliferation of TC. In summary, our data demonstrated that miR-639 upregulation was associated with development of TC, miR-639 promoted cell proliferation and cell cycle by targeting CDKN1A in TC.

Follicular and Diffuse Sclerosing Variant Papillary Thyroid Carcinomas as Independent Predictive Factors of Loco-Regional Recurrence: A Comparison Study Using Propensity Score Matching

BACKGROUND

Only about half of papillary thyroid carcinoma (PTC) cases are classified as conventional PTC (CV-PTC), whereas various histologic variants constitute the remaining cases. Since controversies about the clinical behavior and outcomes of PTC variants continue, the purpose of this study was to compare the outcomes of patients with PTC variants who were treated at a large tertiary referral center in Korea.

METHODS

The medical records for 15,598 CV-PTCs, 435 follicular variants of PTC (FV-PTCs), and 66 diffuse sclerosing variants of PTC (DSV-PTCs) were retrospectively reviewed. Loco-regional recurrences (LRR) among PTC variants were compared using propensity score matching.

RESULTS

Analysis I compared CV-PTC with FV-PTC. After rigorous matching, 367 pairs were established. Recurrence-free survival (RFS) rates in CV-PTC were 96.1% at 5 years, 92.2% at 10 years, and 92.2% at 15 years, while those for FV-PTC were 98.8% at 5 years, 98.8% at 10 years, and 98.8% at 15 years (p = 0.026). Analysis II compared CV-PTC with DSV-PTC. Rigorous matching yielded 56 pairs. RFS rates for CV-PTC were 87.4% at 5 years, 87.4% at 10 years, and 87.4% at 15 years, while those for DSV-PTC were 68.9% at 5 years, 57.5% at 10 years, and were not available at 15 years (p = 0.013).

CONCLUSIONS

Compared with CV-PTC, FV-PTC showed less aggressive behaviors and more favorable outcomes. However, DSV-PTC showed more aggressive behaviors and a less favorable outcome than CV-PTC did. Therefore, the management strategy and follow-up plan for PTC should be differentiated according to the histologic variant.

The Trend of Age-Group Effect on Prognosis in Differentiated Thyroid Cancer

Age has been included in various prognostic scoring systems for differentiated thyroid cancer (DTC). The aim of this study is to re-examine the relationship between age and prognosis by using Surveillance, Epidemiology, and End Results (SEER) population-based database. We identified 51,061 DTC patients between 2004 and 2012. Patients were separated into 10-year age groups. Cancer cause-specific survival (CSS) and overall survival (OS) data were obtained. Kaplan-Meier and multivariable Cox models were built to analyze the outcomes and risk factors. Increasing age gradient with a 10-year interval was associated with the trend of higher proportions for male gender, grade III/IV and summary stage of distant metastases. Both CSS and OS continued to worsen with increasing age, being poorest in in the oldest age group (≥71); multivariate analysis confirmed that CSS continued to fall with each age decade, significantly starting at 60 years (HR = 7.5, 95% 1.0–54.1, p = 0.047) compared to the young group (≤20). Similarly, multivariate analysis suggested that OS continued worsening with increasing age, but starting at 40 years (HR = 3.7, 95% 1.4–10.1, p = 0.009) compared to the young group. The current study suggests that an age exceeding 60 years itself represents an unfavorable prognostic factor and high risk for cancer-specific death in DTC.

Recent incidences and differential trends of thyroid cancer in the USA

The incidence rate of thyroid cancer has been rising rapidly in recent decades; however, its trend remains unclear. To investigate this, we analyzed the database of the Surveillance, Epidemiology and End Results (SEER) 13, 1992-2012 in the USA, particularly focusing on conventional papillary thyroid cancer (CPTC) and follicular variant of PTC (FVPTC). Of the 75,992 thyroid cancers, 61.3% were CPTC and 25.7% were FVPTC, and their incidence rates (IRs) were significantly increased from 1992 to 2012 (P all < 0.001), with CPTC being 2.4 times of FVPTC (P < 0.001) and the overall average annual percent change (AAPC) of incidence being 6.3% in the former and 5.3% in the latter. IRs were increased in all thyroid cancers, albeit most dramatically in PTC, in virtually all ethnic/demographic groups in recent two decades; however, the incidence trends varied among different thyroid cancers, particularly differentiable between CPTC and FVPTC. For example, Joinpoint analyses revealed that the APC of CPTC before 1996 was 1.5% (P > 0.05), which jumped to 6.8% (P < 0.05) after 1996, whereas the APC of FVPTC before 2000 was 6.6% (P < 0.05), which dropped to 4.8% (P < 0.05) after 2000. IRs and incidence trends of PTC were uneven among different ethnic/demographic groups, as exemplified by the lower IRs of both PTC variants in the Black females than in non-Hispanic White females but higher AAPCs of incidence in the former than in the latter. Interestingly, the data also suggest that the rise in the IRs of PTC is becoming plateaued in the most recent 2 years. These novel observations are helpful in understanding the incidence and incidence trends of thyroid cancer.