Genetic Alterations and Their Clinical Implications in High-Recurrence Risk Papillary Thyroid Cancer

Role of contrast-enhanced ultrasound with time-intensity curve analysis about thyroid nodule and parenchyma for differentiating BRAF V600E mutation status

Background

The BRAF V600E mutation was proven associated with papillary thyroid cancer (PTC) which has more aggressive behavior and could affect the outcome of PTC. The objective of this study was to observe more contrast-enhanced ultrasound (CEUS) time-intensity curve (TIC)-based quantitative parameters in nodules and surrounding parenchyma and analyze the association between the TIC-based quantitative parameters and BRAF V600E mutation status in patients with PTC.

Methods

A retrospective analysis of 447 PTC patients was conducted. Prior to thyroidectomy or fine needle aspiration (FNA), all patients had CEUS and had their BRAF V600E mutations examined. Based on their mutation status, the patients were split into two groups. The two groups were compared in terms of sex, age, quantitative CEUS characteristics, pathological findings, vascular invasion, capsular invasion, and cervical lymph node metastases.

Results

A total of 240 patients were in the mutation negative group and 207 patients were in the BRAF mutation positive group. The BRAF-positive group exhibited significantly higher arrival time (AT) and time to peak enhancement (TTP) of the nodules, among other direct quantitative characteristics. The BRAF-positive mutant nodules showed significantly higher arrival time change and time to peak change compared to the surrounding parenchyma for indirect quantitative metrics.

Conclusion

The time-dependent quantitative parameters of CEUS time intensity curve in nodules and surrounding parenchyma have clinical value in distinguishing BRAF V600E mutation positive nodules from gene mutation negative nodules. Quantitative CEUS characteristics may be beneficial in detecting the BRAF V600E mutation status and informing the subsequent clinical choice.

Rearranged During Transfection Rearrangement Detection by Fluorescence In Situ Hybridization Compared With Other Techniques in NSCLC

Introduction

RET rearrangements occur in 1% to 2% NSCLCs. Since no clinically validated RET antibody is currently available, fluorescence in situ hybridization (FISH) is often used as a screening tool to identify patients likely to benefit from RET-targeted therapy. In this study, we performed a comprehensive review of publications in which RET-rearrangement testing was performed by FISH and compared the methods and results with our data.

Methods

The findings of an electronic search for publications using RET-FISH in lung cancer were compared with the results obtained at the Grenoble University Hospital where 784 EGFR -, KRAS -, ALK-, and ROS1-negative NSCLCs were tested by RET break-apart FISH and confirmed by RNA-sequencing (RNA-seq).

Results

Out of the 85 publications using RET-FISH analysis, 52 pertained to patients with lung cancer. The most often used positivity threshold was 15%. Six publications compared RET-FISH with at least one other molecular technique on at least eight samples, and the concordance was variable, from 5.9% to 66.7% for FISH-positive cases. Regarding our data, out of the 784 analyzed samples, 32 (4%) were positive by RET-FISH. The concordance between RET-FISH and RNA-seq in RET-FISH positive samples was 69%.

Conclusions

Overall, both existing literature and our data suggest that RET-FISH testing can be used for rapid screening of RET rearrangements in NSCLC. Nevertheless, using an orthogonal technique such as RNA-seq to confirm RET-FISH-positive cases is essential for ensuring that only patients likely to benefit from RET-target therapy receive the treatment.

FHL1: A novel diagnostic marker for papillary thyroid carcinoma

Although there are clear morphologic criteria for the diagnosis of papillary thyroid carcinoma (PTC), when the morphology is untypical or overlaps, accurate diagnostic indicators are necessary. Since few studies investigated the role of down-regulated genes in PTC, this article aims to further explore the molecular markers associated with PTC. We conducted bioinformatics analysis of gene microarrays of PTC and normal adjacent tissues. Besides, quantitative real-time quantitative polymerase chain reaction array and immunohistochemical staining were used to investigate the expression of the major down-regulated genes. The results indicated that several important down-regulated genes, including TLE1, BCL2, FHL1, GHR, KIT, and PPARGC1A were involved in the process of PTC. Compared to normal adjacent tissues, the mRNA expression of the major genes was down-regulated in PTC (p＜0.05). Immunohistochemically, FHL1 shows negative or low expression in PTC tissues (p＜0.05). BCL2 did not show a significant difference between PTC and normal thyroid tissues (p > 0.05). TLE1, KIT, PPARGC1A and GHR showed negative expression in both tumor and normal tissues. These results suggested that FHL1 could serve as a novel tumor marker for precise diagnosis of PTC.

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.

Essential news for clinical practice—thyroid cancer

Established systemic treatment options for advanced thyroid cancer include the multityrosine kinase inhibitors lenvatinib and sorafenib for radioactive iodine refractory differentiated thyroid cancer (DTC) and vandetanib and cabozantinib for medullary thyroid cancer (MTC). Recently, the COSMIC-311 study resulted in approval of cabozantinib for DTC with progression upon lenvatinib and/or sorafenib; thus, for the first time a specific second-line therapy has been defined for these patients. In addition, the therapeutic landscape of thyroid cancer has been expanded by targeted therapies based on molecular tumor profiles. Selective RET inhibitors such as selpercatinib and pralsetinib show high activity in DTC with RET fusions and MTC with RET mutations, respectively. Further targeted treatment options include NTRK inhibitors for thyroid cancers with NTRK fusions and BRAF-targeted therapy for BRAF V600E-mutated (anaplastic) thyroid cancer.

A new paradigm for epidermal growth factor receptor expression exists in PTC and NIFTP regulated by microRNAs

Intoduction

Identification of molecular alterations associated with tumor behavior is necessary to guide clinical management. The 2022 WHO classification has organized the thyroid follicular cell-derived neoplasms into benign, low-risk and high-risk neoplasms, and emphasized the value of biomarkers that may provide differential diagnostic and prognostic information to avoid overtreatment of low risk neoplasms. This work aims to study the epidermal growth factor receptor (EGFR) expression, functional and spatial dynamics in relation to specific miRNAs alterations in papillary thyroid cancer (PTC) and in non-invasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP) considered as models of high-risk and low-risk thyroid tumors respectively.

Methods

Primary thyroid cultured cells were used for miRNA gain/loss of function and luciferase reporter assays. Paraffin embedded tissues were used for real time PCR, immuno-fluorescence stain and confocal microscopy experiments.

Results

Our results showed that in PTC, EGFR mRNA is reduced as an effect of miR-146b-5p upregulation. The EGF expression is low and the ERK pathway is inhibited. The EGFR protein high cytoplasmic expression and colocalization with the endosomal/exosomal markers, ALIX and CD63, suggest the occurrence of stress-induced EGFR internalization, accumulation in endosomal vesicles and secretion via exosomes. In NIFTP EGFR transcription is increased in association with downregulation of miR-7-5p and the EGFR/ERK pathway is active indicating dependence on the canonical EGFR pathway for growth.

Conclusion

Downregulation of transcript level along with cytoplasmic accumulation of undegraded protein is a new pattern of EGFR regulation associated with malignancy in thyroid. Further research is needed to elucidate the intracellular trafficking defects responsible for this specific EGFR dynamic in PTC.

Thyroid cancer incidence disparities among ethnic Asian American populations, 1990-2014

PURPOSE

Asian/Pacific Islanders (APIs) are at high risk of thyroid cancer, hence we examined thyroid cancer's incidence among disaggregated API subgroups in the United States (U.S.) to identify potential ethnic-specific disparities.

METHODS

Data from 1990 to 2014 in the Surveillance, Epidemiology, and End Results Program (SEER) were used to compare age-adjusted incidence rates (AAIRs) of thyroid cancer for seven API ethnic subgroups to non-Hispanic whites (NHWs) using incidence rate ratios (IRRs) and 95% confidence intervals (CIs). Sex, age, tumor histotype, and year of diagnosis were considered. Trends were evaluated using average annual percent change (AAPC) statistics.

RESULTS

The highest AAIRs (per 100,000 person-years) were among Filipinos (female AAIR=20.49, male AAIR=7.06) and the lowest among Japanese (female AAIR=8.36, male AAIR=3.20). However, Filipinos showed significantly lower incidence of medullary tumors when compared to NHWs (female IRR=0.60, 95% CI 0.40-0.87, male IRR=0.26, 95% CI 0.26-0.51). The largest increasing trends were among Asian Indian/Pakistanis for females (AAPC=5.19, 95% CI 3.81 to 6.58) and Koreans for males (AAPC=4.57, 95% CI 3.14 to 6.03).

CONCLUSIONS

There are clear differences in thyroid cancer incidence and trends when U.S. API ethnic subgroups are examined separately. Disaggregating APIs in research can provide critical information for understanding thyroid cancer risk.

The budget impact of adding pralsetinib to a US health plan formulary for treatment of non-small cell lung cancer and thyroid cancer with RET alterations

BACKGROUND: Lung cancer is the leading cause of cancer death in the United States. Non-small cell lung cancer (NSCLC) accounts for 80% to 85% of all lung cancers. Thyroid cancer, while generally not as lethal as lung cancer, has a large prevalent population and a rapidly increasing incidence in the United States. Pralsetinib is a highly potent, selective rearranged during transfection (RET) inhibitor indicated for the treatment of RET-positive NSCLC and thyroid cancer tumors. OBJECTIVE: To estimate the budget impact of adding pralsetinib to a 1 million-member US health plan formulary for the treatment of patients with metastatic RET fusion-positive NSCLC, advanced or metastatic RET-mutant medullary thyroid cancer (MTC), or advanced or metastatic RET fusion-positive thyroid cancer (non-MTC). METHODS: A budget impact model with a 3-year time horizon was developed in Microsoft Excel to estimate the number of eligible RET-positive NSCLC and thyroid cancer patients in a plan and quantify associated treatment costs (2020 USD). Comparators in the analyses included pralsetinib, selpercatinib, and cabozantinib, as well as indication-specific use of pembrolizumab, pemetrexed/carboplatin combination, vandetanib, lenvatinib, and sorafenib. Drug acquisition, molecular testing, treatment monitoring, and adverse event management costs were included to estimate total annual costs and per-member per-month (PMPM) costs in current (without pralsetinib) and potential future market scenarios, where pralsetinib is assumed to split the projected RET inhibitor market share with selpercatinib. The number of treated patients was based on age- and sex-adjusted incidence of disease, the proportion of patients diagnosed with advanced or metastatic disease, and projected RET testing rates. Treatment duration was based on progression-free survival or duration of response data from clinical trials. Medical resources were monetized using standardized sources such as Medicare reimbursement and wholesale acquisition cost (WAC). RESULTS: The model estimated that there would be approximately 6 new treatment-eligible patients in a 1 million-member plan annually. Monthly WAC is $19,243 for pralsetinib and $20,600 for selpercatinib at the recommended starting dose. Adoption of pralsetinib, with corresponding increases in pralsetinib market share, would be slightly cost saving to a payer, decreasing the overall budget impact to the health plan by $49,985 in year 3 (-$0.0042 PMPM; -$0.0030, -$0.0006, and -$0.0005 for NSCLC, MTC, and thyroid cancer [non-MTC], respectively). In year 3, drug costs were the key driver of total costs (~80%-98%) and cost savings. All other medical resource categories were cost-neutral or nominally cost saving or additive in the budget impact analysis. CONCLUSIONS: Quantifying the budget impact associated with the adoption of new targeted precision therapies is an important consideration for payers. For eligible NSCLC and thyroid cancer patients, our analysis suggests that adoption of pralsetinib is expected to result in modest cost savings for US payers. DISCLOSURES: Support for this study was provided by Blueprint Medicines Corporation. This study was conducted by Veritas Health Economics Consulting, Inc., in collaboration with Blueprint Medicines, which was involved in the design of the study; collection, analysis, and interpretation of the data; writing of the report; and the decision to submit the report for publication. Duff is an employee of Veritas Health Economics Consulting, which received research funding from Blueprint Medicines to develop the budget impact model. Norregaard and Sullivan are employees of Blueprint Medicines. Bargiacchi and Brener were employees of Blueprint Medicines at the time of the research study. This study was presented as a poster at the AMCP Virtual Learning Event, April 2021.

Analytical Accuracy of RET Fusion Detection by Break-Apart Fluorescence In Situ Hybridization

CONTEXT.—

RET gene fusions are oncogenic drivers in nonsmall cell lung cancer and nonmedullary thyroid cancer. Selpercatinib (RETEVMO), a targeted inhibitor of RET, was approved by the US Food and Drug Administration for the treatment of RET fusion-positive nonsmall cell lung cancer and nonmedullary thyroid cancer emphasizing the need for rapid and accurate diagnosis of RET fusions. Fluorescence in situ hybridization (FISH) has been used to detect gene rearrangements, but its performance detecting RET rearrangements is understudied.

OBJECTIVE.—

To validate and describe the performance of Abbott Molecular RET break-apart FISH probes for detecting RET rearrangements.

DESIGN.—

A training set with RET fusion-positive (13) and RET fusion-negative nonsmall cell lung cancer and nonmedullary thyroid cancer samples (12) was used to establish criteria for FISH scoring. The scoring criteria was then applied to a larger validation set of samples (96).

RESULTS.—

A cutoff of 19% or more positive nuclei by FISH was established in the training set and determined by the mean ±3 SD. The validation set was tested using Abbott Molecular RET break-apart FISH compared with sequencing. With this cutoff, a sensitivity of 86% (12 of 14) and specificity of 99% (81 of 82) was achieved. Bootstrapping showed sensitivity could be optimized by using a greater than 13% cutoff with indeterminate samples of 13% to 18% abnormal nuclei requiring confirmation by an orthogonal method. Using this 3-tier scoring system sensitivity increased to 100% (14 of 14) and specificity was 96% (79 of 82).

CONCLUSIONS.—

Abbott Molecular break-apart FISH probes can be used to detect RET fusions. Laboratories can optimize cutoffs and/or testing algorithms to maximize sensitivity and specificity to ensure appropriate patients receive effective, timely therapy.

Clinical significance of eukaryotic translation initiation factor 5A2 in papillary thyroid cancer

Eukaryotic translation initiation factor 5A2 (eIF5A2) plays an important role in tumor progression and prognosis evaluation. However, the potential role of eIF5A2 in human papillary thyroid cancer (PTC) is unknown. In this study, we aim to investigate the association between eIF5A2 expression and PTC clinical outcomes and underlying its Biological function in PTC cells in vitro and in vivo. The expression of eIF5A2 was examined by immunohistochemistry in PTC tissues and its adjacent tissue (n = 39) from 207 PTC patients. Functional analysis of eIF5A2 was performed in PTC cell lines in vitro and in vivo. The results showed that eIF5A2 was overexpressed in PTC tissues compared with the adjacent tissues. Enhanced eIF5A2 expression was significantly correlated with extrathyroidal extension (p = 0.012), lymph node metastasis (p = 0.002), TNM stage (p = 0.006), T classification (p = 0.047) and BRAF V600E mutation (p = 0.036). EIF5A2 inhibition prevented PTC cell growth, invasiveness and migration and induced cell apoptosis in vitro. Furthermore, eIF5A2 depletion inhibited tumor growth and metastasis in vivo. The data indicated that eIF5A2 could be employed as a novel prognostic marker and effective therapeutic target for PTC.

Risk Stratification Using a Novel Genetic Classifier Including PLEKHS1 Promoter Mutations for Differentiated Thyroid Cancer with Distant Metastasis

Background: Although most differentiated thyroid carcinomas (DTCs) have indolent behavior, DTCs with distant metastasis have a poor prognosis. However, there are no validated markers that predict the risk of distant metastasis and the prognosis of DTC. We aimed to develop a genetic classifier for predicting the outcomes of DTC patients with distant metastases. Methods: Targeted deep sequencing of 157 cancer-related genes was performed for 61 DTCs with distant metastases. A candidate mutation was validated with independent thyroid cancer samples using digital polymerase chain reaction. Results: The most frequently mutated gene in the 61 DTCs was BRAF (n = 31, 51%), followed by TERT promoter (n = 28, 46%), NRAS (n = 13, 11%), PLEKHS1 promoter (n = 6, 10%), and STK11 (n = 6, 10%) mutations. PLEKHS1 promoter mutations were more common in the radioactive iodine (RAI)-refractory cases (p = 0.003). Losses of 9q and 11q were associated with RAI-refractory disease (p = 0.002) and cancer-specific mortality (p = 0.028), respectively. In multivariate analysis, bone metastasis (adjusted odds ratio [aOR] = 15.17, 95% confidence interval [CI 3.38-68.06], p < 0.001) and at least one mutation in the TERT promoter, the PLEKHS1 promoter, or TP53 (aOR = 7.64 [CI 1.78-32.76], p = 0.006) remained significant factors associated with RAI-refractoriness. In independently collected papillary thyroid carcinomas without initial distant metastasis (n = 75), a PLEKHS1 promoter mutation was only found in one case that developed distant metastasis during the follow-up period. We developed a genetic classifier consisting of BRAF, RAS, the TERT promoter, the PLEKHS1 promoter, and TP53 for categorizing the prognosis of patients with DTC with distant metastasis. In the poor-prognosis group, 61% of the patients were RAI-refractory and death occurred in 21% during the follow-up. In the intermediate-prognosis group, 29% were RAI-refractory, but no death occurred. In the good-prognosis group, all patients were RAI-responsive and no death occurred. Conclusions: Mutations in the PLEKHS1 promoter are a novel genetic marker of aggressive DTC. Our genetic classifier can be useful for predicting RAI-refractory disease and poor prognosis in DTC patients with distant metastases.

NanoString in the screening of genetic abnormalities associated with thyroid cancer

In the setting of cancer pathology, molecular characterization of tumors providing diagnostic and predictive information is acquiring more and more relevance. Moreover, the advent of innovative technologies continuously improves the knowledge of the molecular landscape of tumors and strengthens the links between clinics, tumor pathology and molecular features. In the clinical management of patients with thyroid nodules and thyroid tumors, the aid of molecular testing is encouraged but still not strongly recommended by current guidelines. Also for this reason this field of study is attracting much interest. The nCounter system is a relatively new technology based on a direct hybridization of fluorescent probes to specific nucleic acid targets, followed by digital measurement of signals; the reaction is highly multiplexable and results are robust and reproducible. This review reports and discusses the available data related to the application of this specific technique to thyroid nodules and thyroid tumors samples. The available data indicate that nCounter system represents a solid approach for the research of relevant diagnostic and prognostic biomarkers in thyroid pathology.

Prediction of cervical lymph node metastasis with contrast-enhanced ultrasound and association between presence of BRAFV600E and extrathyroidal extension in papillary thyroid carcinoma

Objective:

This study aimed to evaluate the correlation between cervical lymph node metastasis (CLNM) and each of the ultrasound features, immunohistochemical factors, and B-type Raf (BRAF^V600E) mutation.

Methods:

A retrospective analysis was performed on 405 patients with single papillary thyroid carcinoma (PTC) nodules, all of whom underwent preoperative sonographic examinations, including gray-scale ultrasound, color Doppler ultrasound, and contrast-enhanced ultrasound (CEUS). All PTC patients were evaluated using 14 clinical and sonographic features, eight immunohistochemical factors, and BRAF^V600E. Multivariate analyses were performed to identify the risk factors for CLNM, and an equation for CLNM was established. The diagnostic value of each modality was compared with a receiver operating characteristic (ROC) curve.

Results:

Among the 405 PTC nodules removed surgically, CLNM was confirmed in 138 patients, whereas extrathyroidal extension was confirmed in 185 patients. Multivariate analyses indicated significant differences between CLNM and non-CLNM groups in three conventional ultrasound features (p < 0.05), whereas other sonographic features, eight immunohistochemical factors, and BRAF^V600E did not indicate significant differences. A ROC curve of 0.757 in the equation exhibited a significant difference compared with the solo factors (p < 0.05 for all). Hyper or isoechoic enhancement at peak time on CEUS was associated with CLNM, whereas the presence of the BRAF^V600E mutation was associated with extrathyroidal extensions although BRAF appeared to be uncorrelated with CLNM in the present study.

Conclusion:

Intensity at peak time, homogeneity, and size are the three most significant features in predicting CLNM in PTC patients, and the presence of the BRAF^V600E mutation was associated with extrathyroidal extensions when PTCs showed a hyper or isoechoic enhancement at peak time in CEUS.

High Preponderance of BRAF V600E Mutation in Papillary Thyroid Carcinoma Among Filipinos: A Clinicopathologic Study

Purpose

BRAF mutation in papillary thyroid carcinoma (PTC) is associated with an aggressive phenotype, with varying incidence. We evaluated the prevalence of BRAF mutations in PTC among Filipino patients and their correlation with clinicopathologic characteristics.

Patients and Methods

Clinicopathologic data were retrieved from 64 sequential patients who underwent thyroidectomy from June 2016 to December 2016. BRAF mutation testing was performed using Sanger sequencing.

Results

Eighteen (28%) of 64 patients were diagnosed with PTC; 12 (70.59%) of 17 harbored a BRAF V600E mutation (no amplification in one patient). Demographics of patients with PTC were as follows: 13 women and five men, with median age of 46 years (range, 25 to 74 years). Fourteen patients had conventional subtype PTC; two, follicular variant; one, oncocytic variant; and one, tall-cell features. Tumor size ranged from 0.8 to 7.0 cm (median, 2.4 cm); extrathyroidal extension was present in seven (38.9%) of 18 patients, multifocality in six (33.33%) of eight, and lymph node involvement in eight (44.4%) of 18. Significant association between presence of a BRAF mutation and presence of extrathyroidal extension or lymph node involvement was not determined due to the limited sample size.

Conclusion

The high preponderance of BRAF mutation (70.59%) suggests some correlation with the previously reported lower 5-year survival among Filipinos. This warrants further investigation in a larger-cohort prospective study.

The stress-activated protein kinase pathway and the expression of stanniocalcin-1 are regulated by miR-146b-5p in papillary thyroid carcinogenesis

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer. Deciphering the pathophysiological mechanisms that contribute to PTC development is essential to the discovery of optimal diagnostic and therapeutic approaches. MiR-146b-5p has been identified as a cancer-associated microRNA highly up-regulated in PTC. This study explores the hypothesis that miR-146b-5p contributes to papillary thyroid carcinogenesis through regulation of cell signaling pathways in a manner that overcomes the cellular growth suppressive events and provides survival advantage. The effect of miR-146b-5p inhibition on major cancer related signaling pathways and expression of Stanniocalcin-1 (STC1), an emerging molecule associated with stress response and carcinogenesis, was tested in cultured primary thyroid cells using luciferase reporter assays, quantitative real-time PCR, immunofluorescence staining, and flow cytometry. Our results demonstrated that miR-146b-5p inhibits the JNK/AP1 pathway activity and down-regulates the expression of STC-1 in thyroid-cultured cells and in thyroid tissue samples. In the presence of miR-146b-5p, PTC cells were resistant to cell death in response to oxidative stress. This is a novel report that miR-146b-5p directly targets STC1 and regulates the activity of JNK/AP1 pathway. Considering the importance of the JNK/AP1 pathway and STC1 in mediating many physiological and pathological processes like apoptosis, stress response and cellular metabolism, a biological regulator of these pathways would have a great scientific and clinical significance.

Intratumoral Genetic Heterogeneity in Papillary Thyroid Cancer: Occurrence and Clinical Significance

Intratumoral heterogeneity (ITH) refers to a subclonal genetic diversity observed within a tumor. ITH is the consequence of genetic instability and accumulation of genetic alterations, two mechanisms involved in the progression from an early tumor stage to a more aggressive cancer. While this process is widely accepted, the ITH of early stage papillary thyroid carcinoma (PTC) is debated. By different genetic analysis, several authors reported the frequent occurrence of PTCs composed of both tumor cells with and without RET/PTC or BRAF^V600E genetic alterations. While these data, and the report of discrepancies in the genetic pattern between metastases and the primary tumor, demonstrate the existence of ITH in PTC, its extension and biological significance is debated. The ITH takes on a great significance when involves oncogenes, such as RET rearrangements and BRAF^V600E as it calls into question their role of driver genes. ITH is also predicted to play a major clinical role as it could have a significant impact on prognosis and on the response to targeted therapy. In this review, we analyzed several data indicating that ITH is not a marginal event, occurring in PTC at any step of development, and suggesting the existence of unknown genetic or epigenetic alterations that still need to be identified.

The BRAF V600E mutation is a predictor of the effect of radioiodine therapy in papillary thyroid cancer

Objective: To investigate the correlation between the BRAF V600E gene mutation and clinicopathological features and thyroid function after iodine-131 treatment in patients with papillary thyroid cancer (PTC). Methods: A total of 128 PTC patients who underwent iodine-131 treatment after a total thyroidectomy from February 2015 to November 2016 at Hunan Cancer Hospital, China, were recruited. There were 25 males and 103 females. The age range was 11 to 73 years old. The BRAF V600E mutation in tumor tissues was detected by amplification-restriction mutation system polymerase chain reaction (ARMS-PCR), and the serum levels of Tg, TSH, Tg-Ab, and Tpo-Ab were measured by chemiluminescence after iodine-131 treatment. The BRAF V600E mutation was shown to be associated with clinicopathological characteristics and thyroid function indicators after iodine-131 treatment. Results: BRAF V600E mutation was detected in 75 of the 128 patients (58.6%) and was observed more frequently in cases with elevated Tg levels (Tg>1.00) at 3, 6, 12, and 18 months after treatment compared with patients without any BRAF mutations (P<0.05). Patients with BRAF V600E mutation had significant lower level of Tg-Ab at 3 and 12 months after treatment with iodine-131 than patients without BRAF V600E mutation (P<0.05). Among the 75 BRAF V600E patients, no significant association was found between the levels of TSH and Tpo-Ab after iodine-131 treatment (P>0.05). The BRAF V600E mutation was closely associated with the high-risk and age of the patient (≥45 years old) (P<0.05), but there was no significant correlation with gender, clinical stage, and distant metastasis. Conclusion: The BRAF V600E mutation is closely related to serum Tg elevation after treatment with iodine-131 in papillary thyroid cancer. These findings suggest that this BRAF mutation may be a predictor of the efficacy of iodine-131 treatment for papillary thyroid cancer.

PIK3CA Gene Mutations in Solid Malignancies: Association with Clinicopathological Parameters and Prognosis

Phosphoinositide kinases (PIKs) are a group of lipid kinases that are important upstream activators of various significant signaling pathways. Hyperactivation of the PI3K/AKT/mTOR pathways—either via mutations or genomic amplification—confers key oncogenic activity, essential for the development and progression of several solid tumors. Alterations in the PIK3CA gene are associated with poor prognosis of solid malignancies. Although the literature reports contradictory prognostic values of PIK3CA in aggressive cancers, most of the available data highlight the important role of PIK3CA mutation in mediating tumorigenesis via increased signaling of the PI3K/AKT/mTOR survival pathway. Several inhibitors of PI3K/AKT/mTOR pathways are investigated as potential therapeutic options in solid malignancies. This article reviews the role of PIK3CA mutations and inhibitors of PI3K/AKT/mTOR pathways in major cancer types and examines its association with clinicopathological parameters and prognosis.

Validation of molecular biomarkers for preoperative diagnostics of human papillary thyroid carcinoma in fine needle aspirates

Background

Despite substantial efforts, reliable preoperative diagnostic for human thyroid malignancies in case of cytologically indeterminate nodules is still missing, resulting in high number of unnecessary thyroidectomies. In an attempt to increase precision of existing preoperative diagnostics, we aimed at validating the panel of molecular biomarkers predictive for papillary thyroid carcinoma (PTC) in preoperative fine needle aspirate (FNA) samples.

Methods

In this prospective study conducted in preoperative thyroid FNA from 44 thyroid nodules, expression levels of 11 molecular biomarkers previously validated on the postoperative samples of PTCs were measured by Cell-to-CT and QuantiGene Plex methods and correlated with final diagnosis.

Results

The QuantiGene Plex resulted in reliable gene expression measurements for FNA and core-needle biopsy (CNB) samples, however this method was less sensitive than pre-amplification based Cell-to-CT. Measurements conducted on the same samples by the two methods significantly correlated for most of the genes. Expression levels of TIMP1, c-MET and ARNTL were upregulated in PTC nodules as compared to benign counterparts, supporting previous post-operative studies. Strong correlation was observed between these biomarker alterations in the same samples. Within the sub-group of 15 indeterminate nodules (Bethesda II-V), TIMP1 had 100% specificity and 83% sensitivity for PTC cases.

Conclusions

Assessment of TIMP1, c-MET and core-clock gene ARNTL expression levels by QuantiGene Plex assay in FNA samples holds promise as an ancillary method to the cytological preoperative diagnostics.

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.

BRAF mutation in papillary thyroid carcinoma (PTC) and its association with clinicopathological features and systemic inflammation response index (SIRI)

The aim of the present research was to investigate the association between the BRAF mutation and papillary thyroid carcinoma (PTC), and further explore the relationship between the systemic inflammation response index (SIRI) and BRAF mutation in patients with PTC. The clinicopathological data were extracted from the patients' medical records from June 2012 to June 2014 in our hospital. We enrolled 95 patients with PTC that have received the total or near-total thyroidectomy and pretracheal and paratracheal lymph node dissection. The blood samples were obtained before surgery. According to the BRAF mutation analysis, the patients were divided into two groups: BRAF mutation positive group and BRAF mutation negative group. The receiver operating characteristic curve (ROC) for the presence of BRAF mutation was used to evaluate the optimal cutoff value of SIRI. The ratio closest to the point with maximum sensitivity and specificity was defined as the optimal cutoff value. Univariate and multivariate logistic regression model were used to confirm the independent factors and compare observed and predicted outcomes. The BRAF mutation rates were 62.1% (59/95). The results indicated that BRAF mutation was significantly correlated with pathological TNM stage, monocyte, SIRI and Galectin-3. The pathological TNM stage, monocyte, SIRI and Galectin-3 were the significant risk factors associated with the presence of BRAF mutation. Moreover, we found that patients with low SIRI had higher BRAF mutation percentage than those with high SIRI, and patients with low monocyte had higher percentage than those with high monocyte. BRAF mutation is associated with the pathological TNM stage, monocyte, SIRI and Galectin-3, and SIRI was the significant risk factor with the BRAF mutation and patients with low SIRI have higher BRAF mutation.

Thyroid cancers of follicular origin in a genomic light: in-depth overview of common and unique molecular marker candidates

In recent years, thyroid malignances have become more prevalent, especially among women. The most common sporadic types of thyroid tumors of follicular origin include papillary, follicular and anaplastic thyroid carcinomas. Although modern diagnosis methods enable the identification of tumors of small diameter, tumor subtype differentiation, which is imperative for the correct choice of treatment, is still troublesome. This review discusses the recent advances in the field of molecular marker identification via next-generation sequencing and microarrays. The potential use of these biomarkers to distinguish among the most commonly occurring sporadic thyroid cancers is presented and compared. Geographical heterogeneity might be a differentiator, although not necessarily a limiting factor, in biomarker selection. The available data advocate for a subset of mutations common for the three subtypes as well as mutations that are unique for a particular tumor subtype. Tumor heterogeneity, a known issue occurring within solid malignancies, is also discussed where applicable. Public databases with datasets derived from high-throughput experiments are a valuable source of information that aid biomarker research in general, including the identification of molecular hallmarks of thyroid cancer.