Genomics and Epigenomics of Medullary Thyroid Carcinoma: From Sporadic Disease to Familial Manifestations

Novel prognostic nomogram for predicting recurrence-free survival in medullary thyroid carcinoma

AIMS

Recently, there have been attempts to improve prognostication and therefore better guide treatment for patients with medullary thyroid carcinoma (MTC). In 2022, the International MTC Grading System (IMTCGS) was developed and validated using a multi-institutional cohort of 327 patients. The aim of the current study was to build upon the findings of the IMTCGS to develop and validate a prognostic nomogram to predict recurrence-free survival (RFS) in MTC.

METHODS AND RESULTS

Data from 300 patients with MTC from five centres across the USA, Europe, and Australia were used to develop a prognostic nomogram that included the following variables: age, sex, AJCC stage, tumour size, mitotic count, necrosis, Ki67 index, lymphovascular invasion, microscopic extrathyroidal extension, and margin status. A process of 10-fold cross-validation was used to optimize the model's performance. To assess discrimination and calibration, the area-under-the-curve (AUC) of a receiver operating characteristic (ROC) curve, concordance-index (C-index), and dissimilarity index (D-index) were calculated. Finally, the model was externally validated using a separate cohort of 87 MTC patients. The model demonstrated very strong performance, with an AUC of 0.94, a C-index of 0.876, and a D-index of 19.06. When applied to the external validation cohort, the model had an AUC of 0.9.

CONCLUSIONS

Using well-established clinicopathological prognostic variables, we developed and externally validated a robust multivariate prediction model for RFS in patients with resected MTC. The model demonstrates excellent predictive capability and may help guide decisions on patient management. The nomogram is freely available online at https://nomograms.shinyapps.io/MTC_ML_DFS/.

International medullary thyroid carcinoma grading system: an Indian tertiary care centre experience

INTRODUCTION

Medullary carcinoma (MTC) is a rare neuroendocrine thyroid neoplasm. The international medullary thyroid carcinoma grading scheme (IMTCGS), which has prognostic significance, has been introduced recently. The present study graded MTC cases using the IMTCGS and evaluated it in our study cohort.

METHODS

All MTC thyroidectomy cases over 6 years were evaluated. Low-grade (LG) and high-grade (HG) were compared. Survival analysis included overall survival (OS), loco-regional free survival and distant metastasis free survival (DMFS).

RESULTS

Of 32 cases, 31.25% were HG and 68.75% LG. The mean age was 44.0 years and M:F ratio 1:1.146. HG patients were older and had tumour cells with high-grade nuclear features and prominent nucleoli and showed distant metastasis. Necrosis was found more in patients with high grade nuclear features. There was discordance between the high Ki67 (60%) and increased mitotic activity (20%). Univariate survival analysis revealed poor DMFRS and OS in the cohorts with high grade, Ki67 > 5% and coagulative necrosis. The multivariate cox regression analysis showed IMTCGS significantly associated with overall survival (HR 28.30, p = 0.009) and DMFS (HR 15.70, p = 0.02).

DISCUSSION AND CONCLUSION

This is the first Indian study evaluating IMTCGS, a very simple and convenient grading system that can be readily used in any tertiary health care centre. IHC for Ki 67 should mandatorily be done irrespective of the low mitotic activity on the HPE and necrosis should be diligently searched in cases with high-grade nuclear morphology. HG MTC cohorts were associated with poor OS as well as DMFRS.

Association of the Genomic Profile of Medullary Thyroid Carcinoma with Tumor Characteristics and Clinical Outcomes in an International Multicenter Study

Purpose: The prognostic importance of RET and RAS mutations and their relationship to clinicopathologic parameters and outcomes in medullary thyroid carcinoma (MTC) need to be clarified. Experimental Design: A multicenter retrospective cohort study was performed utilizing data from 290 patients with MTC. The molecular profile was determined and associations were examined with clinicopathologic data and outcomes. Results: RET germ line mutations were detected in 40 patients (16.3%). Somatic RET and RAS mutations occurred in 135 (46.9%) and 57 (19.8%) patients, respectively. RETM918T was the most common somatic RET mutation (n = 75). RET somatic mutations were associated with male sex, larger tumor size, advanced American Joint Committee Cancer (AJCC) stage, vascular invasion, and high International Medullary Thyroid Carcinoma Grading System (IMTCGS) grade. When compared with other RET somatic mutations, RETM918T was associated with younger age, AJCC (eighth edition) IV, vascular invasion, extrathyroidal extension, and positive margins. RET somatic or germ line mutations were significantly associated with reduced distant metastasis-free survival on univariate analysis, but there were no significant independent associations on multivariable analysis, after adjusting for tumor grade and stage. There were no significant differences in outcomes between RET somatic and RET germ line mutations, or between RETM918T and other RET mutations. Other recurrent molecular alterations included TP53 (4.2%), ARID2 (2.9%), SETD2 (2.9%), KMT2A (2.9%), and KMT2C (2.9%). Among them, TP53 mutations were associated with decreased overall survival (OS) and disease-specific survival (DSS), independently of tumor grade and AJCC stage. Conclusions: RET somatic mutations were associated with high-grade, aggressive primary tumor characteristics, and decreased distant metastatic-free survival but this relationship was not significant after accounting for tumor grade and disease stage. RETM918T was associated with aggressive primary tumors but was not independently associated with clinical outcomes. TP53 mutation may represent an adverse molecular event associated with decreased OS and DSS in MTC, but its prognostic value needs to be confirmed in future studies.

Research progress and application of single-cell sequencing in head and neck malignant tumors

Single-cell sequencing (SCS) is a technology that separates thousands of cells from the organism and accurately analyzes the genetic material expressed in each cell using high-throughput sequencing technology. Unlike the traditional bulk sequencing approach, which can only provide the average value of a cell population and cannot obtain specific single-cell data, single-cell sequencing can identify the gene sequence and expression changes of a single cell, and reflects the differences between genetic material and protein between cells, and ultimately the role played by the tumor microenvironment. single-cell sequencing can further explore the pathogenesis of head and neck malignancies from the single-cell biological level and provides a theoretical basis for the clinical diagnosis and treatment of head and neck malignancies. This article will systematically introduce the latest progress and application of single-cell sequencing in malignant head and neck tumors.

High-grade medullary thyroid carcinoma with papillary-like nuclear features: A report of five cases

BACKGROUND

Medullary thyroid carcinoma (MTC) with papillary-like nuclear features has not been previously described. Here, we aimed to describe the unique features of MTC and examine their prognostic value as markers of high-grade MTC.

METHODS

Of the 110 MTC patients reviewed, a total of five (4.5%) who exhibited MTC with papillary-like nuclear features based on observations from cytological preparations were included in this study. Papillary-like nuclear features were defined as exhibiting all of the following characteristics: ground-glass chromatin pattern, grooves, indented membrane, and lobulation.

RESULTS

The patients included four females and one male, with a median age of 70 years. Calcitonin-doubling times for patients 1 and 3 were 0.8 and 0.34 years, respectively. Cytologically, patients 4 and 5 displayed a Ki-67 labeling index of 5.1% and necrotic cells, respectively. All three histologically evaluated patients exhibited papillary-like nuclear features and a Ki-67 labeling index of >5.0%. Patients 1 and 3 had mitotic counts of ≥5 per 2 mm2 . The MTC in all five patients was classified as high-grade. Moreover, patient 1 harbored a RET mutation (M918T), while RET (R912W), BRAF (V600E), and CTNNB1 (S33F, T41I) mutations were present in patient 2.

CONCLUSION

Our work suggests that papillary-like nuclear features in MTC may be associated with high-grade tumors. These findings may be cytologically indicative of high-grade tumors other than necrosis or mitosis.

Ki67 proliferation index in medullary thyroid carcinoma: a comparative study of multiple counting methods and validation of image analysis and deep learning platforms

AIMS

The International Medullary Thyroid Carcinoma Grading System, introduced in 2022, mandates evaluation of the Ki67 proliferation index to assign a histological grade for medullary thyroid carcinoma. However, manual counting remains a tedious and time-consuming task.

METHODS AND RESULTS

We aimed to evaluate the performance of three other counting techniques for the Ki67 index, eyeballing by a trained experienced investigator, a machine learning-based deep learning algorithm (DeepLIIF) and an image analysis software with internal thresholding compared to the gold standard manual counting in a large cohort of 260 primarily resected medullary thyroid carcinoma. The Ki67 proliferation index generated by all three methods correlate near-perfectly with the manual Ki67 index, with kappa values ranging from 0.884 to 0.979 and interclass correlation coefficients ranging from 0.969 to 0.983. Discrepant Ki67 results were only observed in cases with borderline manual Ki67 readings, ranging from 3 to 7%. Medullary thyroid carcinomas with a high Ki67 index (≥ 5%) determined using any of the four methods were associated with significantly decreased disease-specific survival and distant metastasis-free survival.

CONCLUSIONS

We herein validate a machine learning-based deep-learning platform and an image analysis software with internal thresholding to generate accurate automatic Ki67 proliferation indices in medullary thyroid carcinoma. Manual Ki67 count remains useful when facing a tumour with a borderline Ki67 proliferation index of 3-7%. In daily practice, validation of alternative evaluation methods for the Ki67 index in MTC is required prior to implementation.

YTHDF3as a prognostic predictive biomarker of thyroid cancer and its correlation with immune infiltration

PURPOSE

Thyroid cancer (TC) is one of the most common endocrine malignancies, and its morbidity continues to rise. N6-methyladenosine (m6A) RNA methylation, an epigenetic modification, is an important regulator of gene expression in TC. Therefore, it's worth finding the characteristics and predictive value of the m6A RNA methylation regulators in thyroid cancer (TC).

METHOD

RNA-seq data of TC was downloaded from the Cancer Genome Atlas (TCGA) database to screen out the differential expressed regulators. The absolute contraction selection operator (Lasso) Cox regression was used to construct the risk model of m6A methylation regulators. The predictive value of the risk scoring model was evaluated by Kaplan Meier (K-M) analysis and receiver operating characteristic (ROC) curves. The underlying mechanism of m6A methylation regulators in TC was predicted by gene set enrichment analysis (GSEA). Further validation was performed by using immunohistochemistry (IHC) and q-PCR. The correlation between risk-related gene and immune infiltration was evaluated by Tumour Immune Estimation Resource (TIMER).

RESULTS

IGF2BP2, YTHDF1 and YTHDF3 were screened out as strong independent prognostic factors of TC. Then a risk score model was established to further screen the predictors. Finally, according to the results of overall survival (OS) and clinical characteristics of TC, YTHDF3 was screened out as a potential predictor. Meanwhile, IHC and qPCR confirmed that YTHDF3 was expressed differential in TC. The expression of YTHDF3 was positively associated with the infiltration level of CD4+ T cells and macrophages. It was strongly correlated with a variety of immune markers in TC.

CONCLUSION

We confirmed that YTHDF3 can be used as a potential prognostic biomarker of TC. It not only plays a decisive role in the initiation and development of TC, but also provides a new perspective for understanding the modification of m6A RNA in TC.

Independent Validation of the International Grading System for Medullary Thyroid Carcinoma: A Single Institution Experience

Medullary thyroid carcinoma (MTC), an uncommon C cell thyroid malignancy, accounts for a disproportionate number of thyroid cancer deaths. To predict MTC clinical behavior, the recent international MTC grading system (IMTCGS) was published combining features from the Memorial Sloan Kettering Cancer Center and Royal North Shore Hospital grading systems that incorporates mitotic count, necrosis, and Ki67 proliferative index (Ki67PI). The IMTCGS appears promising, but independent validation data are limited. Here, we applied the IMTCGS to our institutional MTC cohort and assessed its ability to predict clinical outcomes. Our cohort comprised 87 MTCs (30 germline and 57 sporadic). Slides for each case were reviewed by 2 pathologists and histologic features recorded. Ki67 immunostaining was performed on all cases. Each MTC was graded with the IMTCGS based on tumor necrosis, Ki67PI, and mitotic count. Cox regression analysis was performed to assess the impact of various clinical and pathological data on disease outcomes, including overall survival (OS), disease-free survival, disease-specific survival (DSS), and distant metastasis-free survival. In our MTC cohort, 18.4% (n = 16/87) were IMTCGS high grade. IMTCGS grade was strongly prognostic for OS, disease-free survival, DSS, and distant metastasis-free survival on univariate analysis and multivariable analysis in both the entire MTC cohort and in the sporadic subset. Among the individual IMTCGS parameters, while all 3 were associated with poorer survival outcomes on univariate analysis, necrosis had the strongest association with all survival parameters on multivariable analysis, whereas Ki67PI or mitotic count was associated only with OS and DSS. This retrospective study independently demonstrates that the IMTCGS is valid for grading MTCs. Our findings support incorporating IMTCGS into routine pathology practice. IMTCGS grading may help clinicians to better predict the prognosis of MTC. Future studies may shed light on how MTC grading should impact treatment protocols.

Challenges in the care of patients with RET-altered thyroid cancer: a multicountry mixed-methods study

BACKGROUND

The discovery of driver oncogenes for thyroid carcinomas and the identification of genomically targeted therapies to inhibit those oncogenes have altered the treatment algorithm in thyroid cancer (TC), while germline testing for RET mutations has become indicated for patients with a family history of RET gene mutations or hereditary medullary TC (MTC). In the context of an increasing number of selective RET inhibitors approved for use, this paper aims to describe challenges and barriers affecting providers' ability to deliver optimal care for patients with RET-altered TC across the patient healthcare journey.

METHODS

A mixed-method educational and behavioral needs assessment was conducted in Germany (GER), Japan (JPN), the United Kingdom (UK), and the United States (US) prior to RET-selective inhibitor approval. Participants included medical oncologists (MO), endocrinologists (EN) and clinical pathologists (CP) caring for patients affected with TC. Data collection tools were implemented in three languages (English, German, Japanese). Qualitative data were coded and thematically analyzed in NVivo. Quantitative data were analyzed via frequency and crosstabulations in SPSS. The findings presented here were part of a broader study that also investigated lung cancer challenges and included pulmonologists.

RESULTS

A total of 44 interviews and 378 surveys were completed. Suboptimal knowledge and skills were self-identified among providers, affecting (1) assessment of genetic risk factors (56%, 159/285 of MOs and ENs), (2) selection of appropriate genetic biomarkers (59%, 53/90 of CPs), (3) treatment plan initiation (65%, 173/275 of MOs and ENs), (4) management of side effects associated with multitargeted tyrosine kinase inhibitors (78%, 116/149 of MOs and ENs), and (5) transfer of patients into palliative care services (58%, 160/274 of MOs and ENs). Interviews underscored the presence of systemic barriers affecting the use of RET molecular tests and selective inhibitors, in addition to suboptimal knowledge and skills necessary to manage the safety and efficacy of targeted therapies.

CONCLUSION

This study describes concrete educational needs for providers involved in the care of patients with RET-altered thyroid carcinomas. Findings can be used to inform the design of evidence-based education and performance improvement interventions in the field and support integration into practice of newly approved RET-selective inhibitors.

Top 10 Nested Pattern Head and Neck Lesions to Notice

BACKGROUND

Nested is defined as "cellular clusters arranged in small groupings with intervening vascular or stromal networks, lacking lumens or glandular formation." Using this definition, multiple neoplastic and non-neoplastic lesions of the head and neck come into the differential. We have broadly organized the differential diagnosis of "nested" tumors into entities with neuroendocrine differentiation, squamous differentiation, thyroid follicular cell differentiation, and other lesions.

METHODS

Review.

RESULTS

Many different entities have a nested appearance and the morphologic, immunohistochemical, clinical, and radiographic features contribute to the differential diagnosis. The different tumors covered in this review include neuroendocrine neoplasms, paraganglioma, middle ear neuroendocrine tumor (formerly known as middle ear adenoma), medullary thyroid carcinoma, poorly differentiated thyroid carcinoma, olfactory neuroblastoma, ectopic pituitary neuroendocrine tumor, hyalinizing trabecular tumor, solid subtype of papillary thyroid carcinoma, solid cell nests/C-cell hyperplasia, necrotizing sialometaplasia, and meningioma.

CONCLUSION

In this review, we discuss the morphologic and immunohistochemical features of the covered entities as a guide to differential diagnosis when nested-patterned head and neck lesions are encountered.

Update on C-Cell Neuroendocrine Neoplasm: Prognostic and Predictive Histopathologic and Molecular Features of Medullary Thyroid Carcinoma

Medullary thyroid carcinoma (MTC) is a C-cell-derived epithelial neuroendocrine neoplasm. With the exception of rare examples, most are well-differentiated epithelial neuroendocrine neoplasms (also known as neuroendocrine tumors in the taxonomy of the International Agency for Research on Cancer [IARC] of the World Health Organization [WHO]). This review provides an overview and recent evidence-based data on the molecular genetics, disease risk stratification based on clinicopathologic variables including molecular profiling and histopathologic variables, and targeted molecular therapies in patients with advanced MTC. While MTC is not the only neuroendocrine neoplasm in the thyroid gland, other neuroendocrine neoplasms in the thyroid include intrathyroidal thymic neuroendocrine neoplasms, intrathyroidal parathyroid neoplasms, and primary thyroid paragangliomas as well as metastatic neuroendocrine neoplasms. Therefore, the first responsibility of a pathologist is to distinguish MTC from other mimics using appropriate biomarkers. The second responsibility includes meticulous assessment of the status of angioinvasion (defined as tumor cells invading through a vessel wall and forming tumor-fibrin complexes, or intravascular tumor cells admixed with fibrin/thrombus), tumor necrosis, proliferative rate (mitotic count and Ki67 labeling index), and tumor grade (low- or high-grade) along with the tumor stage and the resection margins. Given the morphologic and proliferative heterogeneity in these neoplasms, an exhaustive sampling is strongly recommended. Routine molecular testing for pathogenic germline RET variants is typically performed in all patients with a diagnosis of MTC; however, multifocal C-cell hyperplasia in association with at least a single focus of MTC and/or multifocal C-cell neoplasia are morphological harbingers of germline RET alterations. It is of interest to assess the status of pathogenic molecular alterations involving genes other than RET like the MET variants in MTC families with no pathogenic germline RET variants. Furthermore, the status of somatic RET alterations should be determined in all advanced/progressive or metastatic diseases, especially when selective RET inhibitor therapy (e.g., selpercatinib or pralsetinib) is considered. While the role of routine SSTR2/5 immunohistochemistry remains to be further clarified, evidence suggests that patients with somatostatin receptor (SSTR)-avid metastatic disease may also benefit from the option of ¹⁷⁷Lu-DOTATATE peptide radionuclide receptor therapy. Finally, the authors of this review make a call to support the nomenclature change of MTC to C-cell neuroendocrine neoplasm to align this entity with the IARC/WHO taxonomy since MTCs represent epithelial neuroendocrine neoplasms of endoderm-derived C-cells.

MicroRNA-206 in human cancer: Mechanistic and clinical perspectives

MicroRNAs (miRNAs), small non-coding RNAs approximately 20-25 nt in length, play important roles via directly binding to the corresponding 3' UTR of target mRNAs. Recent research has shown that miRNAs cover a wide range of diseases, including several types of cancer. It is interesting to note that miR-206 operates as a tumor suppressor and is downregulated in abundant cancer types, such as breast cancer, lung cancer, colorectal cancer, and so forth. Interestingly, a growing number of studies have also reported that miR-206 could function as an oncogene and promote tumor cell proliferation. Thereby, miR-206 may act as either oncogenes or tumor suppressors under certain conditions. In addition, it was widely acknowledged that restoring tumor-suppressor miR-206 has emerged as an unconventional cancer therapy strategy. Therefore, miR-206 might be a newfangled procedure for achieving a more significant treatment outcome for cancer patients. This review summarizes the role of miR-206 in several cancer types and the contributions made between miR-206 and the diagnosis, treatment, and drug resistance of solid tumors.

Molecular genotyping in medullary thyroid cancer

PURPOSE OF REVIEW

There has been a significant advance in our understanding of the molecular biology of medullary thyroid cancer (MTC) alongside progress in the development of targeted therapies including multikinase and specific rearranged during transfection inhibitors.

RECENT FINDINGS

This review will examine the latest data investigating the impact of the genomics of MTC on the prediction of the natural history of an individual's disease and the determination, selection and timing of treatment interventions.

SUMMARY

Recent advances in genotyping in MTC and the development of targeted therapies have impacted on the clinical management of both sporadic and hereditary MTC.

Non-Apoptotic Programmed Cell Death in Thyroid Diseases

Thyroid disorders are among the most common endocrinological conditions. As the prevalence of thyroid diseases increases annually, the exploration of thyroid disease mechanisms and the development of treatments are also gradually improving. With the gradual advancement of therapies, non-apoptotic programmed cell death (NAPCD) has immense potential in inflammatory and neoplastic diseases. Autophagy, pyroptosis, ferroptosis, and immunogenic cell death are all classical NAPCD. In this paper, we have compiled the recent mechanistic investigations of thyroid diseases and established the considerable progress by NAPCD in thyroid diseases. Furthermore, we have elucidated the role of various types of NAPCD in different thyroid disorders. This will help us to better understand the pathophysiology of thyroid-related disorders and identify new targets and mechanisms of drug resistance, which may facilitate the development of novel diagnostic and therapeutic strategies for patients with thyroid diseases. Here, we have reviewed the advances in the role of NAPCD in the occurrence, progression, and prognosis of thyroid diseases, and highlighted future research prospects in this area.

Integrated proteogenomic characterization of medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine malignancy derived from parafollicular cells (C cells) of the thyroid. Here we presented a comprehensive multi-omics landscape of 102 MTCs through whole-exome sequencing, RNA sequencing, DNA methylation array, proteomic and phosphoproteomic profiling. Integrated analyses identified BRAF and NF1 as novel driver genes in addition to the well-characterized RET and RAS proto-oncogenes. Proteome-based stratification of MTCs revealed three molecularly heterogeneous subtypes named as: (1) Metabolic, (2) Basal and (3) Mesenchymal, which are distinct in genetic drivers, epigenetic modification profiles, clinicopathologic factors and clinical outcomes. Furthermore, we explored putative therapeutic targets of each proteomic subtype, and found that two tenascin family members TNC/TNXB might serve as potential prognostic biomarkers for MTC. Collectively, our study expands the knowledge of MTC biology and therapeutic vulnerabilities, which may serve as an important resource for future investigation on this malignancy.

MANAGEMENT OF ENDOCRINE DISEASE: Medullary thyroid cancer: from molecular biology and therapeutic pitfalls to future targeted treatment perspectives

During the last decades, knowledge of the molecular biology in medullary thyroid carcinoma (MTC) and specifically on the role of rearranged during transfection (RET)-activating mutations in tumorigenesis has led to the evolution of novel targeted therapies, mainly tyrosine kinase inhibitors (TKIs). Vandetanib and cabozantinib have been approved for the management of metastatic progressive MTC. Two novel, highly selective RET inhibitors, selpercatinib and pralsetinib, have recently been approved for the treatment of RET-mutant MTCs and RET-fusion differentiated thyroid cancer. The administration of targeted therapies in MTC patients has changed the therapeutic strategies; however, in the majority of cases, there are no real data showing an improvement of prognosis by TKIs in MTC. Drug resistance remains the main reason for treatment failure. Thus, the understanding of the molecular landscape of tumorigenesis and the mechanisms underlying resistance to targeted therapies is of paramount importance for the further development of more efficient therapies for MTC. The present review focuses on the molecular pathways implicated in MTC tumorigenesis, the approved targeted therapies, the tumoral escape mechanisms, as well as the future perspectives for targeted therapy.

Diagnostic Strategies and Algorithms for Investigating Cancer Predisposition Syndromes in Children Presenting with Malignancy

Simple Summary

Here we provide an overview of several genetically determined conditions that predispose to the development of solid and hematologic malignancies in children. Diagnosing these conditions, whose prevalence is estimated around 10% in children with cancer, is useful to warrant personalized oncologic treatment and follow-up, as well as psychological and genetic counseling to these children and their families. We reviewed the most recent studies focusing on the prevalence of cancer predisposition syndromes in cancer-bearing children and the most-used clinical screening tools. Our work highlighted the value of clinical screening tools in the management of young cancer patients, especially in settings where genetic testing is not promptly accessible.

Abstract

In the past recent years, the expanding use of next-generation sequencing has led to the discovery of new cancer predisposition syndromes (CPSs), which are now known to be responsible for up to 10% of childhood cancers. As knowledge in the field is in constant evolution, except for a few “classic” CPSs, there is no consensus about when and how to perform germline genetic diagnostic studies in cancer-bearing children. Several clinical screening tools have been proposed to help identify the patients who carry higher risk, with heterogeneous strategies and results. After introducing the main clinical and molecular features of several CPSs predisposing to solid and hematological malignancies, we compare the available clinical evidence on CPS prevalence in pediatric cancer patients and on the most used decision-support tools in identifying the patients who could benefit from genetic counseling and/or direct genetic testing. This analysis highlighted that a personalized stepwise approach employing clinical screening tools followed by sequencing in high-risk patients might be a reasonable and cost-effective strategy in the care of children with cancer.

Management of thyroid nodules

In the past 30 years, there has been a substantial rise in the detection of thyroid nodules. Largely asymptomatic, thyroid nodules are most often incidental findings that typically pose minimal risk. Data supporting these findings show a rapid rise in the incidental detection of thyroid nodules and cancer, but minimal effect on mortality rates, despite treatment. These data imply that historical approaches to thyroid nodule and cancer care might at times include unnecessary or excessive care. To address this issue, the past decade has witnessed an increasingly conservative approach to nodule management, seeking to individualise care and provide the most focused intervention that leads to favourable outcomes. Benign nodules can be safely monitored with minimal, or long-interval follow-up imaging. Molecular testing should be considered for cytologically indeterminate nodules because of its ability to improve preoperative cancer risk determination and reduce unnecessary surgery. The treatment of biopsy-proven malignant nodules has become increasingly nuanced, since recommendations for near-total thyroidectomy are no longer routine. Hemithyroidectomy is now commonly considered when operative intervention is favoured. Some patients with small volume, isolated cancerous nodules are safely managed non-operatively with active monitoring. In summary, modern management strategies for thyroid nodular disease seek to incorporate the growing amount of available diagnostic and prognostic data, inclusive of demographic, radiological, pathological and molecular findings. Once obtained, an individualised management plan can be effectively formulated.

Clinical Application of Next-Generation Sequencing in Advanced Thyroid Cancers

Background: With the emergence of mutation-based systemic therapies for patients with advanced thyroid cancer, molecular profiling has become an important component of care. Although next-generation sequencing (NGS) gene panels are accessible to clinicians, there is no consensus on the optimal approach to testing. This study investigates the clinical application of NGS results in the management of advanced thyroid cancer. Methods: Patients with advanced thyroid cancer with NGS completed as part of the Integrated Molecular Profiling in Advanced Cancers Trial (IMPACT; NCT01505400) or Ontario-wide Cancer TArgeted Nucleic Acid Evaluation (OCTANE; NCT02906943) clinical trials at the Princess Margaret Cancer Centre were included. Electronic medical records were reviewed to collect clinicopathologic and treatment data. The OncoKB framework was used to categorize molecular alterations based on levels of actionability. Patients with an actionable alteration by OncoKB framework who had treatment with a drug targeting the alteration were categorized as receiving "matched" therapy. Time-to-event data were analyzed using the Kaplan-Meier method. This study was approved by the University Health Network Research Ethics Board (ID# 19-5888). Results: NGS was performed on 118 patients with advanced thyroid cancer between 2013 and 2020. The most common molecular alterations included BRAF V600E (62%) and NRAS (15%) mutations in papillary thyroid cancer, RET alterations (78%) in medullary thyroid cancer, and BRAF V600E (38%) and TP53 (62%) mutations in anaplastic thyroid cancer. Actionable alterations were found in 87% of patients, and 57% of patients had at least one Level 1 or 2 alteration for which Food and Drug Administration (FDA)-approved drug is available. BRAF and RET alterations made up 86% of Level 1 and 2 alterations. A matched therapeutic approach was undertaken in 13% of patients. Conclusion: This study uses a structured framework to analyze the actionability and clinical use of NGS results in advanced thyroid cancer. Most patients had at least one potentially actionable mutation and 57% of patients had at least one Level 1 or 2 alteration, predominantly driven by BRAF V600E and RET alterations. This study rationalizes the need for routine multigene NGS testing or reflex BRAF and RET testing in the management of patients with advanced thyroid cancer.

Medullary Thyroid Carcinoma Mutational Spectrum Update and Signaling-Type Inference by Transcriptional Profiles: Literature Meta-Analysis and Study of Tumor Samples

Simple Summary

Medullary thyroid carcinoma (MTC) is a rare but clinically relevant tumor based on its aggressiveness and the limited therapeutic opportunities currently available for advanced cases. A better understanding of the mechanisms of MTC development is crucial to identify more effective means of intervention and therapies. Several studies have shown that RET and RAS genes play a central role in MTC. However, little is known about the signaling processes operating downstream of these genes. Here, we report mutation and gene expression profiles in proprietary sporadic MTCs, including both primary and metastatic tumors. We show that tumors derived from the same patient display similar expression profiles and that the latter can be used to obtain information about specific downstream signaling, identifying distinct molecular subtypes. Furthermore, by reviewing the relevant literature, we highlight that, along with RET and RAS, other less frequent genes are emerging as possible new players in MTC.

Abstract

Medullary thyroid carcinoma (MTC) is a rare but aggressive tumor. Although RET and RAS genes are recognized drivers in MTC, associated downstream signaling pathways are largely unknown. In this study, we report 17 sporadic MTCs, collected at our institution, comprising patient-matched primary and lymph node metastatic tumors investigated for mutational and transcriptional profiles. As we identified two uncommon RET deletions (D898_E901del and E632_L633del), we also performed a literature review and meta-analysis to assess the occurrence of unconventional alterations in MTC, focusing on next-generation sequencing studies. We found that new gene alterations are emerging, along with the known RET/RAS drivers, involving not only RET by multiple concurrent mutations or deletions but also other previously underestimated cancer-related genes, especially in sporadic MTCs. In our MTC gene profiles, we found transcriptome similarity between patient-matched tissues and expression of immune genes only by a few samples. Furthermore, we defined a gene signature able to stratify samples into two distinct signaling types, termed MEN2B-like and MEN2A-like. We provide an updated overview of the MTC mutational spectrum and describe how transcriptional profiles can be used to define distinct MTC signaling subtypes that appear to be shared by various gene drivers, including the unconventional ones.

Curcumin induces autophagic cell death in human thyroid cancer cells

Curcumin, a polyphenolic compound, is a well-known anticancer agent, although its poor bioavailability remains a big concern. Recent studies suggest that autophagy-targeted therapy may be a useful adjunct treatment for patients with thyroid cancer. Curcumin acts as an autophagy inducer on many cancer cells. However, little is known about the exact role of curcumin on thyroid cancer cells. In the present study, curcumin significantly inhibited the growth of thyroid cancer cells. Autophagy was markedly induced by curcumin treatment as evidenced by an increase in LC3-II conversion, beclin-1 accumulation, p62 degradation as well as the increased formation of acidic vesicular organelles (AVOs). 3-MA, an autophagy inhibitor, partially rescued thyroid cancer cells from curcumin-induced cell death. Additionally, curcumin was found to exert selective cytotoxicity on thyroid cancer cells but not normal epithelial cells and acted as an autophagy inducer through activation of MAPK while inhibition of mTOR pathways. Hyperactivation of the AKT/mTOR axis was observed in the majority of PTC samples we tested, and thyroid cancer cell lines along with cancer tissue specimens sustained a low basal autophagic activity. Taken together, our results provide new evidence that inducing autophagic cell death may serve as a potential anti-cancer strategy to handle thyroid cancer.

Opportunities and Challenges of Liquid Biopsy in Thyroid Cancer

Thyroid cancer is the most common malignancy of the endocrine system, encompassing different entities with distinct histological features and clinical behavior. The diagnostic definition, therapeutic approach, and follow-up of thyroid cancers display some controversial aspects that represent unmet medical needs. Liquid biopsy is a non-invasive approach that detects and analyzes biological samples released from the tumor into the bloodstream. With the use of different technologies, tumor cells, free nucleic acids, and extracellular vesicles can be retrieved in the serum of cancer patients and valuable molecular information can be obtained. Recently, a growing body of evidence is accumulating concerning the use of liquid biopsy in thyroid cancer, as it can be exploited to define a patient's diagnosis, estimate their prognosis, and monitor tumor recurrence or treatment response. Indeed, liquid biopsy can be a valuable tool to overcome the limits of conventional management of thyroid malignancies. In this review, we summarize currently available data about liquid biopsy in differentiated, poorly differentiated/anaplastic, and medullary thyroid cancer, focusing on circulating tumor cells, circulating free nucleic acids, and extracellular vesicles.

Update on Targeted Therapy in Medullary Thyroid Cancer

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor that accounts for 2-4% of all thyroid cancers. All inherited MTC and approximately 50% of sporadic cases are driven by mutations in the REarranged during Transfection (RET) proto-oncogene. The recent expansion of the armamentarium of RET-targeting tyrosine kinase inhibitors (TKIs) has provided effective options for systemic therapy for patients with metastatic and progressive disease. However, patients that develop resistant disease as well as those with other molecular drivers such as RAS have limited options. An improved understanding of mechanisms of resistance to TKIs as well as identification of novel therapeutic targets is needed to improve outcomes for patients with MTC.