BRAF V600E mutation does not predict recurrence after long-term follow-up in TNM stage I or II papillary thyroid carcinoma patients

BRAF V600E mutation co-existing with oncogenic mutations is associated with aggressive clinicopathologic features and poor prognosis in papillary thyroid carcinoma

BACKGROUND

The aim of this study was to evaluate the correlation among mutations in cancer-related genes, clinicopathologic features, and clinical outcome in classical papillary thyroid carcinoma (PTC).

PATIENTS AND METHODS

A total of 130 patients with classical PTC who underwent curative surgery between April 2012 and June 2023 at Hokuto Hospital were included. Mutations in targeted regions of 160 cancer-related genes were detected by next-generation sequencing (NGS)-based cancer panel testing.

RESULTS

The BRAF V600E mutation was detected in 108 (83.1%) of 130 PTC patients. Among the 108 patients with the BRAF V600E mutation, other co-existing oncogenic mutations were found in 12 (9.2%) patients. When we divided into 3 groups of no mutations, BRAF V600E mutation alone, and BRAF V600E and other oncogenic mutations, significant differences were observed in terms of tracheal invasion (P = 0.0024), and bilateral neck lymph node metastasis (P = 0.0047). Kaplan-Meier analysis of overall survival (OS) revealed patients with BRAF V600E and other oncogenic mutations had significantly poorer survival than those with BRAF V600E mutation alone (P = 0.0026). Multivariate cox proportional hazard analysis revealed BRAF V600E and other oncogenic mutations was an independent prognostic factor for OS (HR: 10.559; 95%CI: 1.007-110.656, P = 0.0493).

CONCLUSIONS

The BRAF V600E mutation co-existing with other oncogenic mutations but not the BRAF V600E mutation alone was associated with aggressive clinicopathologic features, resulting in poor prognosis in patients with classical PTC. Detection of oncogenic mutations using NGS-based cancer panel testing could enhance understanding of the clinical features of classical PTC.

METTL3-Induced miR-222-3p Upregulation Inhibits STK4 and Promotes the Malignant Behaviors of Thyroid Carcinoma Cells

CONTEXT

Abnormally high expression of N6-methyladenosine (m6A) methyltransferase-like 3 (METTL3) has been implied to accompany thyroid carcinoma (TC) development.

OBJECTIVE

This study aimed to explore the protumorigenic role and downstream signaling axis of METTL3 in TC.

METHODS

This study was conducted at the Sun Yat-Sen Memorial Hospital Sun Yat-Sen University. METTL3 and miR-222-3p were overexpressed or downregulated in TC cells. Tumor and adjacent normal tissues were collected from 80 patients (19 men and 60 women, aged 30-70 years) with a pathological diagnosis of TC from January 2012 to January 2015. Cells were classified and subjected to different treatments. The expression of METTL3 was validated in TC tissues and cell lines. In functional studies, METTL3 and miR-222-3p were overexpressed or downregulated in TC cells to evaluate their effects on malignant behaviors, which were subsequently verified by xenografts in nude mice.

RESULTS

The expression of METTL3 was elevated in TC, correlating with poor prognosis of TC patients. Heightened METTL3 expression accelerated malignant behaviors of TC cells. Mechanistically, METTL3 stimulated miR-222-3p expression by mediating the m6A modification of pri-miR-222-3p. miR-222-3p targeted and inversely regulated serine/threonine stress kinase 4 (STK4). Knockdown of METTL3 augmented STK4 expression by downregulating miR-222-3p, thereby suppressing the malignant behaviors of TC cells as well as tumor growth and lung metastasis in nude mice.

CONCLUSION

Silencing METTL3 suppresses miR-222-3p expression and thus stimulates STK4 expression, thereby repressing the malignancy and metastasis of TC.

Brown adipose tissue (BAT) activation at 18F-FDG PET/CT: correlation with clinicopathological characteristics in breast cancer

Background

There is conflicting results of few published human 18F-FDG PET/CT studies about BAT activation in breast cancer (BC). The aim of the study is to evaluate the association between the levels of BAT metabolic activity detected by 18F-FDG PET/CT and clinicopathological characteristics of a tumor in patients with primary BC.

Results

BAT was activated in 16 out of 157 (10.2%) consecutive female patients with BC who underwent 18F-FDG PET/CT for initial evaluation. The majority of patients (15/16) had bilateral uptake in the supraclavicular regions. The mean values of the highest SUVmax and total metabolic activity (TMA) of activated BAT were 13.3 ± 9.9 and 79.6 ± 45, respectively. Median outdoor temperature was significantly lower in the activated BAT group (P value=0.035). Patients with BAT activation tended to have a lower median primary tumor size and primary SUVmax, but not statistically significant than those without BAT activation. BAT activation was significantly more frequent among younger age groups (14/16) and patients with lower body mass index (BMI) (10/16), but it was insignificantly more frequent among estrogen receptor-positive (ER+), progesterone receptor-positive (PR+), human epidermal growth factor receptor2 negative (HER2-), invasive ductal carcinoma (IDC), grade II, luminal B subtype, high Ki-67 expression level, patients with positive nodal metastasis, and in patients without distant metastasis. TMA was significantly higher among HER2+ patients (P value=0.019), but insignificantly higher among the younger age groups, stages I and II, invasive lobular carcinoma (ILC), grade I, luminal B subtype, ER+, PR−, higher Ki-67 expression level, patients with positive nodal, and distant metastasis. BMI and patient’s age were the significant independent predictor factors for BAT activation on multivariate regression analysis.

Conclusion

BAT activation in young age females is sex hormone-dependent, positively associated with less aggressive molecular subtypes of BC, less frequent in patients with distant metastasis. BAT activation may be a prognostic factor that carries a better prognosis in BC.

Papillary thyroid carcinoma with a high tumor mutation burden has a poor prognosis

BACKGROUND

Tumor mutation burden (TMB) as a prognostic marker for immunotherapy has shown prognostic value in many cancers. However, there is no systematic investigation on TMB in papillary thyroid carcinoma (PTC).

METHODS

Based on the somatic mutation data of 487 PTC patients from The Cancer Genome Atlas (TCGA), TMB was calculated, and we classified the samples into high-TMB (H-TMB) and low-TMB (L-TMB) groups. Bioinformatics methods were used to explore the characteristics and potential mechanism of TMB in PTC.

RESULTS

High TMB predicts shorter progression-free survival (PFS) (P < 0.001). TMB was positively correlated with age, stage, tumor size, metastasis, the male sex and tall cell PTC. Compared to the L-TMB group, the H-TMB group presented with lower immune cell infiltration, a higher proportion of tumor-promoting immune cells (M0 macrophages, activated dendritic cells and monocytes) and a lower proportion of antitumor immune cells (M1 macrophages, CD8⁺ T cells and B cells). Additionally, the characteristics displayed by different TMB groups were not driven by critical driver mutations such as BRAF and RAS.

CONCLUSIONS

PTC patients with high TMB have a worse prognosis. By stratifying PTC patients according to their TMB, advanced PTC patients who are candidates for immunotherapy could be selected.

Characterization of BRAF mutation in patients older than 45 years with well-differentiated thyroid carcinoma

Introduction

Papillary thyroid carcinoma is the most frequent endocrine neoplasia and its incidence has tripled over the past 35 years. Although papillary thyroid carcinoma carries a good prognosis, 10%−30% of patients still develop recurrence and metastasis. Some clinical and genetic features are associated with worse prognosis. The most frequent mutation is the BRAF p.V600E, which has been associated with many clinical features of poor prognosis. However, many studies have produced controversial results without any association between BRAF mutation and clinicopathological features of poor prognosis.

Objective

Since the prognostic value of BRAF mutations remains controversial, this study aims to investigate the importance of this mutation in therapeutic decisions for papillary thyroid carcinoma.

Methods

Therefore, we evaluated whether the presence of BRAF mutation is associated with features of poor prognosis in 85 patients with papillary thyroid carcinoma older than 45 years treated at A.C. Camargo Cancer Center, from 1980 to 2007. BRAF mutation was evaluated by pyrosequencing. Statistical analysis was performed using SPSS.

Results

The mean age of patients was 54 years (range: 45 − 77 years), 73 were women (85.8%) and 12 were men (14.2%). Among them, 39 cases (45.9%) presented extrathyroidal extension and 11 cases had recurrent disease. BRAF mutation was detected in 57 (67%) patients. No significant association was observed between BRAF mutation and gender (p  = 0.743), age (p  = 0.236), N-stage (p  = 0.423), vascular and perineural infiltration (p  = 0.085 or multifocality (p  = 1.0). Although not statistically significant, the majority of patients with recurrent disease were BRAF positive (9 out of 11) (p  = 0.325). Patients affected by BRAF mutation are associated with tumors larger than 1 cm (p  = 0.034) and with extrathyroidal extension (p  = 0.033).

Conclusion

Although BRAF testing is widely available, there are no consistent data to support improvement in outcomes from incorporating it into therapeutic decision for thyroid cancer.

Association of MicroRNA Expression and BRAFV600E Mutation with Recurrence of Thyroid Cancer

Many miRNAs and cancer-related mutations have been proposed as promising molecular markers of papillary thyroid carcinoma (PTC). However, there are limited data on the correlation between miRNA expression, BRAFV600E mutation, and PTC recurrence. Therefore, to evaluate the potential of BRAFV600E mutation and five selected miRNAs (-146b, -222, -21, -221, -181b) in predicting PTC recurrence, these molecular markers were analyzed in 400 formalin-fixed, paraffin-embedded PTC tissue specimens. The expression levels of miRNAs were measured using qRT-PCR. It was demonstrated that expression levels of all analyzed miRNAs are significantly higher in recurrent PTC than in non-recurrent PTC (p < 0.05). Moreover, higher expression levels of miR-146b, miR-222, miR-21, and miR-221 were associated with other clinicopathologic features of PTC, such as tumor size and lymph node metastases at initial surgery (p < 0.05). No significant differences in the frequency of BRAFV600E mutation in recurrent PTC and non-recurrent PTC were determined. Our results suggest that miRNA expression profile differs in PTC that is prone to recurrence when compared to PTC that does not reoccur after the initial surgery while BRAFV600E mutation frequency does not reflect the PTC recurrence status. However, the prognostic value of the analyzed miRNAs is rather limited in individual cases as the pattern of miRNA expression is highly overlapping between recurrent and non-recurrent PTC.

BRAF V600E Status and Stimulated Thyroglobulin at Ablation Time Increase Prognostic Value of American Thyroid Association Classification Systems for Persistent Disease in Differentiated Thyroid Carcinoma

BACKGROUND

Stimulated thyroglobulin levels measured at the time of remnant ablation (A-hTg) and BRAFV600E mutation had shown prognostic value in predicting persistent disease in differentiated thyroid cancer (DTC). The aim of this study was to evaluate the prognostic role of A-hTg combined with the BRAFV600E status in association with the revised American Thyroid Association (ATA) risk stratification.

MATERIAL AND METHODS

620 patients treated for a DTC were included in this study with a median follow-up duration of 6.1 years. All patients underwent total thyroidectomy followed by radioiodine ablation. Patients with positive anti-thyroglobulin antibodies were excluded. The predictive value of A-hTg was calculated by receiver operating characteristic curve (ROC curve) analysis. The Cox proportional hazard regression model, including the BRAF status, A-hTg, and ATA classification system, was assessed to evaluate the existing persistent disease risk.

RESULTS

Taken together, the BRAF status and A-hTg levels improve the ATA risk classification in all categories. In particular, in the low-risk ATA classification, only the combination of BRAFV600E+A-hTg > 8.9ng/ml was associated with persistent disease (P = 0.001, HR 60.2, CI 95% 5.28-687). In the intermediate-risk ATA classification, BRAFWT+A-hTg > 8.9ng/ml was associated with persistent disease (P = 0.029, HR 2.71, CI 95% 1.106-6.670) and BRAFV600E+A-hTg > 8.9ng/ml was also associated with persistent disease (P < 0.001, HR 5.001, CI 95% 2.318-10.790). In the high-risk ATA classification, both BRAFV600E+A-hTg < 8.9ng/ml and BRAFV600E+A-hTg > 8.9 ng/ml were associated with persistent disease (P = 0.042, HR 5.963, CI 95% 1.069-33.255 and P = 0.002, HR 11.564, CI 95% 2.543-52.576, respectively).

CONCLUSIONS

The BRAF status and stimulated thyroglobulin levels at ablation time improve the ATA risk stratification of differentiated thyroid cancer; therefore, even A-hTg could be included in risk classification factors.

Suppression of long non-coding RNA TNRC6C-AS1 protects against thyroid carcinoma through DNA demethylation of STK4 via the Hippo signalling pathway

Objectives

Thyroid carcinoma (TC) represents a malignant neoplasm affecting the thyroid. Current treatment strategies include the removal of part of the thyroid; however, this approach is associated with a significant risk of developing hypothyroidism. In order to adequately understand the expression profiles of TNRC6C‐AS1 and STK4 and their potential functions in TC, an investigation into their involvement with Hippo signalling pathway and the mechanism by which they influence TC apoptosis and autophagy were conducted.

Methods

A microarray analysis was performed to screen differentially expressed lncRNAs associated with TC. TC cells were employed to evaluate the role of TNRC6C‐AS1 by over‐expression or silencing means. The interaction of TNRC6C‐AS1 with methylation of STK4 promoter was evaluated to elucidate its ability to elicit autophagy, proliferation and apoptosis.

Results

TNRC6C‐AS1 was up‐regulated while STK4 was down‐regulated, where methylation level was elevated. STK4 was verified as a target gene of TNRC6C‐AS1, which was enriched by methyltransferase. Methyltransferase’s binding to STK4 increased expression of its promoter. Over‐expressed TNRC6C‐AS1 inhibited STK4 by promoting STK4 methylation and reducing the total protein levels of MST1 and LATS1/2. The phosphorylation of YAP1 phosphorylation was decreased, which resulted in the promotion of SW579 cell proliferation and tumorigenicity.

Conclusion

Based on our observations, we subsequently confirmed the anti‐proliferative, pro‐apoptotic and pro‐autophagy capabilities of TNRC6C‐AS1 through STK4 methylation via the Hippo signalling pathway in TC.

PFKFB2 Promoter Hypomethylation as Recurrence Predictive Marker in Well-Differentiated Thyroid Carcinomas

Despite the low mortality rates, well-differentiated thyroid carcinomas (WDTC) frequently relapse. BRAF and TERT mutations have been extensively related to prognosis in thyroid cancer. In this study, the methylation levels of selected CpGs (5-cytosine-phosphate-guanine-3) comprising a classifier, previously reported by our group, were assessed in combination with BRAF and TERT mutations. We evaluated 121 WDTC, three poorly-differentiated/anaplastic thyroid carcinomas (PDTC/ATC), 22 benign thyroid lesions (BTL), and 13 non-neoplastic thyroid (NT) tissues. BRAF (V600E) and TERT promoter (C228T and C250T) mutations were tested by pyrosequencing and Sanger sequencing, respectively. Three CpGs mapped in PFKFB2, ATP6V0C, and CXXC5 were evaluated by bisulfite pyrosequencing. ATP6V0C hypermethylation and PFKFB2 hypomethylation were detected in poor-prognosis (PDTC/ATC and relapsed WDTC) compared with good-prognosis (no relapsed WDTC) and non-malignant cases (NT/BTL). CXXC5 was hypomethylated in both poor and good-prognosis cases. Shorter disease-free survival was observed in WDTC patients presenting lower PFKFB2 methylation levels (p = 0.004). No association was observed on comparing BRAF (60.7%) and TERT (3.4%) mutations and prognosis. Lower PFKFB2 methylation levels was an independent factor of high relapse risk (Hazard Ratio = 3.2; CI_95% = 1.1–9.5). PFKFB2 promoter methylation analysis has potential applicability to better stratify WDTC patients according to the recurrence risk, independently of BRAF and TERT mutations.

Are BRAF V600E and K-Ras Mutations Associated With Tumor Aggressiveness in Well-Differentiated Thyroid Cancer?

Aim:

Many clinical studies have shown an association between B-type rapidly growing fibrosarcoma kinase [BRAF(V600E)] mutation and aggressive clinicopathologic features, although some results from others are controversial. Besides, Kirsten rat sarcoma (K-Ras) mutations are more common in endemic iodine deficiency regions, as our country is. However, use of the biologic markers are questioned in clinical practice; they are beginning to be used for the management of patients with thyroid nodules and cancers. The aim of the present study was to evaluate the prevalence of the BRAF(V600E) mutation in tumor samples and its relationship to high-risk clinicopathologic features.

Methods:

From 2000 to 2007, 82 patients with well-differentiated thyroid cancer (WDTC) who underwent surgery in Ege University were enrolled retrospectively in the study. Univariate and multivariate analyses were performed to analyze associations between BRAF(V600E) and K-Ras mutations and clinicopathologic features. We identified 82 patients with WDTC (male:female = 1:3.2).

Results:

The median follow-up was 96 months. The mean age was 46.4 (16–80). None of the all analyzed prognostic factors—age; sex; lymph node metastasis; multifocality; multicentricity; invasion; tumor diameter; and tumor, node, metastasis staging—were correlated with BRAF(V600E) mutation status in the univariate analysis. Meanwhile, none of the analyzed prognostic factors were correlated with K-Ras mutation status.

Discussion:

Although many studies suggest BRAF(V600E) and K-Ras mutations as prognostic factors in WDTC, our results are controversial. BRAF(V600E) and K-Ras mutations have no significant effects on tumor aggressiveness in Turkish patients with WDTC. Our results underline that it is too early to reach a conclusion that BRAF(V600E) and K-Ras mutations are involved with poor clinical outcomes.

Targeted next-generation sequencing of cancer-related genes in thyroid carcinoma: A single institution's experience

Thyroid carcinoma (TC) has characteristic genetic alterations, including point mutations in proto-oncogenes and chromosomal rearrangements that vary by histologic subtype. Recent developments in next-generation sequencing (NGS) technology enable simultaneous analysis of cancer-associated genes of interest, thus improving diagnostic accuracy and allowing precise personalized treatment for human cancer. A total of 50 patients who underwent thyroidectomy between 2014 and 2016 at Hokuto Hospital were enrolled. Total DNA was extracted from formalin-fixed, paraffin-embedded tissue sections and quantified. Targeted regions of 24 cancer-associated genes were amplified by PCR, barcoded and sequenced using an Illumina MiSeq platform. Subjects included 30 patients with papillary carcinoma (PC), two with PC tall cell variant (TVPC), two with PC follicular variant (FVPC), eight with follicular carcinoma, seven with poorly differentiated carcinoma (PDC), and one with anaplastic carcinoma (AC). The BRAF V600E mutation was present in 25 of 30 (83%) patients with PC, 2 of 2 (100%) patients with TVPC, 6 of 7 (86%) patients of PDC, and one patient with AC. PIK3CA mutations were present in 3 of 30 (delPV104P, A1046T and C420R; 10%) patients with PC and 1 of 7 (H1047R; 14%) patients with PDC. The TP53 mutation was present in 1 of 30 (R306*; 3.3%) patients with PC and 1 of 7 (Q152*; 14%) patients with PDC. The NRAS mutation was present in 1 of 2 (Q61K, 50%) patients with FVPC. Statistical analysis showed that patients without the BRAF V600E mutation had advanced pathologic T and N stages compared with those with the mutation (P=0.047 and P=0.019, respectively). The BRAF V600E mutation was not correlated with overall and disease-free survival in patients with PC. A patient with PC with a mutation in EGFR (K852Q) and the PIK3CA mutation had an aggressive course with multiple bone and lung metastases. Detection of mutations in cancer-associated genes using NGS could enhance the understanding of the clinical behavior of TC.

B-Raf mutation and papillary thyroid carcinoma patients

Thyroid carcinoma is the most prevalent endocrine neoplasm globally. In the majority of thyroid carcinoma cases, a positive prognosis is predicted following administration of the appropriate treatment. A wide range of genetic alterations present in thyroid carcinoma exert their oncogenic actions partially through the activation of the mitogen-activated protein kinase pathway, with the B-Raf mutation in particular being focused on by experts for decades. The B-Raf gene has numerous mutations, however, V600E presents with the highest frequency. It is believed that the existence of the V600E mutation may demonstrate an association with the clinicopathological characteristics of patients, however, inconsistencies remain in the literature. A number of explanatory theories have been presented in order to resolve these discrepancies. Recently, it has been suggested that the V600E mutation may function as a target in a novel approach that may aid the diagnosis and prognosis of thyroid carcinoma, with a number of vying methods put forward to that effect. The current review aims to assist researchers in further understanding the possible association between B-Raf mutations and thyroid carcinoma.

BRAF(V600E) Is Correlated with Recurrence of Papillary Thyroid Microcarcinoma: A Systematic Review, Multi-Institutional Primary Data Analysis, and Meta-Analysis

BACKGROUND

Given the increasing incidence of papillary thyroid carcinoma despite stable disease-specific mortality rates, the potential for the disease to reoccur is a key outcome to predict. The BRAF(V600E) mutation has been associated with recurrent disease in larger tumors. However, its correlation in papillary thyroid microcarcinoma (PTMC) is not clear in individual series.

METHODS

The MEDLINE, EMBASE, Web of Science, and Cochrane databases were searched for studies including patients with PTMC undergoing initial surgical treatment. Studies with at least two years of follow-up, BRAF genotyping (the comparator), and recurrence as an outcome were included, as were unpublished primary data on 485 patients from two institutions. The metameter analyzed was odds ratio (OR) for recurrence between patients with BRAF(V600E) versus BRAF wild type (BRAFwt).

RESULTS

The initial search identified 431 references. After screening of the abstracts for inclusion, 44 manuscripts were reviewed in full by two independent reviewers. Four published studies and primary data from two institutional cohorts were included in the final analysis. A meta-analysis of 2247 PTMC patients revealed that patients with a BRAF(V600E) mutation had a higher likelihood for recurrence (odds ratio 2.09 [confidence interval 1.31-3.33], p = 0.002).

CONCLUSIONS

This meta-analysis shows that BRAF mutational status correlates with recurrence of PTMCs, highlighting the potential utility of genotyping in preoperative and postoperative planning. BRAF mutation may be helpful in risk-stratifying patients with PTMC for surgical management versus observation.

Best practice of BRAF V600E mutation testing for the diagnosis and management of thyroid cancers

BRAF V600E mutation is the single most common genetic alteration identified in papillary thyroid carcinoma. There is significant association between BRAF V600E mutation and aggressive tumor behavior. BRAF V600E mutation has also been found to be an independent predictor of treatment failure and tumor recurrence even in patients with low-stage disease. Pre-operative BRAF mutation testing of thyroid fine needle aspiration specimens has become a routine clinical practice that enhances the predictability of malignancy in indeterminate fine needle aspiration cytology specimens especially those in the follicular lesion of undetermined significance/atypia of undetermined significance category. In addition to histological evaluation of subsequent core needle biopsy and BRAF immunohistochemistry, an expanded panel of mutation testing including BRAF V600E, NRAS, HRAS, RET/papillary thyroid carcinoma and PAX8/PPARγ rearrangements are currently advocated to further improve the diagnostic predictability in the detection of thyroid carcinomas using cytological specimens.

The BRAF V600E mutation in papillary thyroid cancer with positive or suspected pre-surgical cytological finding is not associated with advanced stages or worse prognosis

The mutation BRAF V600E is thought to be a putative prognostic marker of the aggressiveness of several cancers among which is also papillary thyroid cancer. Our study aimed to evaluate whether this mutation is associated with advanced stages of disease or with a worse prognosis in a series of patients with cytological findings of Thyr 4 and Thyr 5 and who were undergoing total thyroidectomy and routine central compartment lymph-node dissection. 110 patients were consecutively enrolled over an 18-month period from September 2010 to March 2012. All patients had cytological findings that were either indicative of, or positive for papillary thyroid cancer, Thyr 4 or Thyr 5. Detection of BRAF mutation was made on fine-needle aspiration specimen by pyrosequencing after microdissection and DNA extraction of neoplastic cells. After surgical intervention, the patients underwent radioiodine ablation according to our protocol, and follow-up was performed after 8 months. The BRAF V600E mutation was found in 79 % of our cases: 85.7 % of these cases represented the classical variant, 57.8 % the follicular variant, 89.6 % the tall cell variant, and 33.3 % the solid variant. All patients had confirmation of papillary thyroid cancer after histology, with no differences being seen in pTNM presentation between patients with BRAF wild-type and patients with BRAF V600E mutation. Ninety-nine patients underwent radioiodine ablation. Results at follow-up 8 months after radioiodine ablation showed no differences in the rate of ablation between patients harboring BRAF V600E mutation and those having BRAF wild-type. The BRAF V600E mutation doesn't appear to be a reliable risk factor for the aggressiveness of a tumor. BRAF analysis should neither be the only guide for pre-surgical decisions regarding the extent of surgery nor for post-surgical decisions regarding the aggressiveness of the treatment.

The tall cell variant of papillary thyroid carcinoma: clinical and pathological features and outcomes

BACKGROUND

The tall cell variant (TCV) is a relatively rare variant of papillary thyroid cancer. Since a controversy exists whether or not the TCV has a worse outcome, the aim of our study was to retrospectively compare the clinicopathological features and outcomes in a group of TCV patients and a larger group of patients with classical papillary thyroid carcinoma (cPTC).

SUBJECTS AND METHODS

Data from 30 TCV and 293 cPTC patients were analyzed. Among the 293 cPTC, we also selected a "high-risk" cPTC group (no.=103) that was treated with the same protocol used for the TCV patients. All data were managed by Cox analysis.

RESULTS

Compared to all cPTC patients, TCV subjects displayed only a significantly higher rate of extrathyroid extension. At multivariate analysis, TCV was not an independent variable for the prediction of a high risk of persistent/recurrent disease. At the last follow-up observation, there was no difference in the disease status between the TCV and all cPTC patients. Moreover, "high-risk" cPTC patients had a significant increase in persistent/recurrent disease.

CONCLUSIONS

In our study, although the TCV histotype is associated with a higher prevalence of extrathyroid extension, it is characterized by an outcome that is not significantly different from that of all cPTC patients and is more favorable than that of "high-risk" cPTC patients. Only those TCV patients classified as "high risk" based on specific pathological and clinical features, according to current guidelines, should be treated aggressively, such as with a total thyroidectomy, neck lymph node dissection or ablative radioiodine treatment.

Clinical Significance of BRAF Mutation in Thyroid Papillary Cancer

Objective

To correlate the presence of BRAF V600E mutation with clinicopathological parameters.

Study Design

Case-control study.

Setting

BRAF mutation represents the most common oncogenic event in sporadic papillary thyroid cancer (PTC). There are, however, significant discrepancies regarding the overall frequency and its relationship with clinicopathological parameters of poor outcome. We analyzed BRAF mutation in a cohort of patients affected by PTCs to identify its association with clinical variables.

Subjects and Methods

We analyzed retrospectively a series of 304 patients, treated for PTC from 1999 to 2011 at Bologna University Hospital. We searched BRAF mutation by reverse transcription polymerase chain reaction (PCR) followed by PCR and direct sequencing.

Results

BRAF mutation was found in 77.4% of classical PTCs, 31.9% of the follicular variant, and 72.2% of high tall cell PTCs, being significantly associated, at univariate analysis, with recurrence, stage, multicentricity, histologic subtype, extrathyroidal extension, nodule dimension, body mass index, and American Thyroid Association (ATA) risk stratification. Furthermore, higher T, but not N or M, stage was associated with BRAF mutation. In the multivariate analysis, the BRAF mutation was significantly associated only with the ATA risk stratification, in turn showing a significant negative association with recurrence-free survival time with Cox multivariate analysis.

Conclusion

Our results indicate that BRAF mutation identifies a subset of PTC with increased risk of recurrence. The presence of BRAF mutation might be a valuable diagnostic and prognostic marker of the disease. To confirm the diagnostic usefulness of this marker, further studies should be carried out.

Biotinidase is a novel marker for papillary thyroid cancer aggressiveness

Biotinidase was identified in secretome analysis of thyroid cancer cell lines using proteomics. The goal of the current study was to analyze the expression of biotinidase in thyroid cancer tissues and fine needle aspiration (FNA) samples to evaluate its diagnostic and prognostic potential in thyroid cancer. Immunohistochemical analysis of biotinidase was carried out in 129 papillary thyroid cancer (PTC, 34 benign thyroid tissues and 43 FNA samples and correlated with patients' prognosis. Overall biotinidase expression was decreased in PTC compared to benign nodules (p = 0.001). Comparison of aggressive and non-aggressive PTC showed decrease in overall biotinidase expression in the former (p = 0.001). Loss of overall biotinidase expression was associated with poor disease free survival (p = 0.019, Hazards ratio (HR) = 3.1). We examined the effect of subcellular compartmentalization of nuclear and cytoplasmic biotinidase on patient survival. Decreased nuclear expression of biotinidase was observed in PTC as compared to benign tissues (p<0.001). Upon stratification within PTC, nuclear expression was reduced in aggressive as compared to non-aggressive tumors (p<0.001). Kaplan-Meier survival analysis showed significant association of loss of nuclear biotinidase expression with reduced disease free survival (p = 0.014, HR = 5.4). Cytoplasmic biotinidase expression was reduced in aggressive thyroid cancers in comparison with non-aggressive tumors (p = 0.002, Odds ratio (OR) = 0.29) which was evident by its significant association with advanced T stage (p = 0.003, OR = 0.28), nodal metastasis (p<0.001, OR = 0.16), advanced TNM stage (p<0.001, OR = 0.21) and extrathyroidal extension (p = 0.001, OR = 0.23). However, in multivariate analysis extrathyroidal extension emerged as the most significant prognostic marker for aggressive thyroid carcinomas (p = 0.015, HR = 12.8). In conclusion, loss of overall biotinidase expression is a novel marker for thyroid cancer aggressiveness.