Clinical Utility of Circulating Cell-Free DNA Mutations in Anaplastic Thyroid Carcinoma

Promising Therapeutic Targets for Recurrent/Metastatic Anaplastic Thyroid Cancer

OPINION STATEMENT

Anaplastic thyroid cancer presents formidable challenges, particularly in cases of recurrence or metastasis. Timely BRAF V600E testing is imperative at diagnosis, initially through immunohistochemistry, followed by comprehensive genomic profiling encompassing genes such as NTRK, RET, ALK, and assessment of tumor mutation burden (TMB). FDA-approved treatment options include dabrafenib and trametinib for patients with BRAF mutations, while those exhibiting high TMB may benefit from pembrolizumab. Further therapeutic decisions hinge upon mutational profile, urgency of response required, airway integrity, and access to targeted therapies There is growing use of immunotherapy for ATC based on published reports of activity, but currently there is no FDA approved agent for ATC. The off-label utilization of "precision medicine" combinations imposes a considerable financial strain, underscoring the necessity for further clinical trials to elucidate promising therapeutic avenues for this orphan disease. There is a pressing need for the development and support of clinical trials investigating genomically driven and immune-based therapies for anaplastic thyroid cancer.

Characterization of the Thyroid Cancer Genomic Landscape by Plasma-Based Circulating Tumor DNA Next-Generation Sequencing

Background: The limited availability of targeted therapies in thyroid cancer (TC) has challenged conventional treatment algorithms and has established urgency for the identification of targetable genomic abnormalities. In addition to widely adopted tissue-based next-generation sequencing (NGS), plasma-based circulating tumor DNA (ctDNA) NGS is rapidly emerging as a genomic biomarker detection method and is steadily gaining utility across solid tumors. To date, plasma-based genomic alterations in TC have not been determined. Herein, we profile potential actionable mutations detected through ctDNA in patients with TC subtypes. Methods: A retrospective data analysis of the Guardant Health, Inc. database was performed using the commercially available Guardant360® plasma-NGS test on TC samples from adult patients collected between 2016 and 2021. The landscape of genomic alterations and blood tumor mutation burden (bTMB) were analyzed in patients with different types of TC: anaplastic TC (ATC), papillary TC (PTC), follicular TC (FTC), oncolytic carcinoma of the thyroid (OCA), poorly differentiated TC (PDTC), medullary TC (MTC), and TC not otherwise specified (TC NOS). Results: Of the 1094 patients included most of the patients n = 876 had TC NOS, and 20% had a specific diagnosis (92 ATC, 62 PTC, 14 FTC, 16 OCA, 2 PDTC, and 32 MTC patients). The median age was 65 (range 10-98) and 47.3% were male. 78.3% of patients had one or more genomic alteration detected by ctDNA NGS. TP53 (46.9%) was the most common mutation detected among all TC. BRAFV600E was detected in 27.2% of ATC, 35.7% of PTC, and in none of FTC. RAS was detected in 18.5% of ATC, 11.9% of PTC, and 62.5% of FTC. RET, ALK, and NTRK fusions were seen in 1.1%, 0.5%, and 0.2% of all TC, respectively. RET mutations were detected in 66.7% of MTC. bTMB analysis was performed on 159 patients. The mean bTMB was higher in ATC compared with other types of TC (p = 0.0011, 0.0557, and <0.0001, respectively). Conclusions: Plasma-based comprehensive NGS is a promising NGS method in TC; however, future validation of the clinical utility by analysis of paired tumor and plasma samples is needed.

Genomic alterations in thyroid cancer: biological and clinical insights

Tumours can arise from thyroid follicular cells if they acquire driver mutations that constitutively activate the MAPK signalling pathway. In addition, a limited set of additional mutations in key genes drive tumour progression towards more aggressive and less differentiated disease. Unprecedented insights into thyroid tumour biology have come from the breadth of thyroid tumour sequencing data from patients and the wide range of mutation-specific mechanisms identified in experimental models, in combination with the genomic simplicity of thyroid cancers. This knowledge is gradually being translated into refined strategies to stratify, manage and treat patients with thyroid cancer. This Review summarizes the biological underpinnings of the genetic alterations involved in thyroid cancer initiation and progression. We also provide a rationale for and discuss specific examples of how to implement genomic information to inform both recommended and investigational approaches to improve thyroid cancer prognosis, redifferentiation strategies and targeted therapies.

Comparative study on the mutation spectrum of L-MYC and C-MYC genes of blood cfDNA in patients with ovarian cancer and healthy females

BACKGROUND

This study aimed at detecting the mutations of L-MYC and C-MYC genes in ovarian cancer (OC) patients and healthy female volunteers using cell-free DNA (cfDNA).

METHODS

We evaluated cfDNA of 50 OC patients with different stages (I-IV) and 50 age-matched healthy female volunteers (controls) in order to access mutations in exon-1 of L-MYC (198 bp) and exon-3 of C-MYC (165 bp) genes using Sanger sequencing.

RESULTS

The total mutations reported were 43 and 7 in exon-1 of L-MYC and exon-3 of C-MYC genes, respective. The C-MYC and L-MYC gene mutational status recorded in both cases and controls were compared with the already available data on mutations in c-myc and L-myc databases viz SNP db-NCBI, ClinVar db, COSMIC, PubMed, and LitVar which suggested that the detected mutations in exon-1 of L-MYC and exon-3 of C-MYC genes are novel.

CONCLUSION

Our study showed that cfDNA might be used for noninvasive detection of clinico-genomic profiles of OC patients and as a prognostic biomarker for the disease.

History of Thyroid Surgery in the Last Century

Before the 20th century, thyroid surgery was regarded as "horrid butchery" such that no honest and sensible surgeon would ever engage in it. Yet, by the mid-20th century, thyroidectomy had become a respected, life-saving, safe, and increasingly practiced operation. From Kocher to Wells and onward into the 21st century, the evolution of thyroid surgery has continued, enhanced by the integration of endocrinology, genetics, immunology, physiology, technology, training, and multidisciplinary care. The ability to personalize and optimize the care of thyroid disorders has been progressively achieved through shared insights and discoveries, highlights of which are described herein.

Detection of driver mutations in plasma cell-free nucleic acids in differentiated thyroid neoplasm

IMPORTANCE

This proof-of-concept paper demonstrates that driver mutations can be detected in plasma in differentiated thyroid tumors, and we were able to detect mutations in upto 80% malignant thyroid nodules. Additionally, cancer subtypes could also be predicted using a 8-gene panel. In almost 90% follicular adenoma, rat sarcoma virus (RAS) mutations were detectable. There was a strong agreement between driver mutations found in plasma samples, FNAC materials, and histopathology samples. This has potential as a noninvasive, preoperative diagnostic tool (particularly of clinical importance in indeterminate nodules) and may help in detection of residual tumor after surgery. Future research is warranted to test the role of this tool to detect tumor recurrence.

OBJECTIVE

Ultrasonographic (USG) evaluation and fine-needle aspiration (FNA) are cornerstone for evaluation of thyroid neoplasm. Molecular technique including detection of driver mutation from FNA cytology (FNAC) material is an established modality. In this study, we explored the feasibility of using plasma cell-free nucleic acids to identify known driver mutations in differentiated thyroid neoplasm.

DESIGN

Patients presenting with thyroid nodules underwent USG with Thyroid Image Reporting and Data Systems scoring and FNAC (Bethesda classification). All patients in Bethesda 3, 4, 5, 6 underwent surgery and histopathological confirmation. Patients in Bethesda 2 (cosmetic concerns, compressive symptoms) underwent surgery, and rest were presumed benign on the basis of USG, FNAC features, and clinical followup.).

SETTING

Endocrinology clinic.

PARTICIPANTS

Subjects with thyroid nodule.

INTERVENTION(S) OR EXPOSURE(S)

None.

MAIN OUTCOME(S) AND MEASURE(S)

Plasma sample, FNA, and histopathology material were evaluated for driver mutations (8-gene panel comprising BRAF-V600E, RET/PTC3, RET/PTC1, TERT promoter, HRAS, NRAS, KRAS, and PAX8-PPARG).

RESULTS

A total of 223 subjects were recruited; of these 154 were benign and 69 had differentiated thyroid cancer. We were able to detect driver mutation from plasma in 55 subjects (79.71%) of all malignant patients, and 11 patients in benign category had RAS mutation (follicular adenoma). Rest of the benign nodules did not have any detectable driver mutations.

CONCLUSIONS AND RELEVANCE

Plasma might be a viable noninvasive alternative source for detection of driver mutations (8-gene panel) in subjects with differentiated thyroid tumors and may have significant clinical utility.

Molecular mechanisms of resistance to kinase inhibitors and redifferentiation in thyroid cancers

Protein kinases play critical roles in cell survival, proliferation, and motility. Their dysregulation is therefore a common feature in the pathogenesis of a number of solid tumors, including thyroid cancers. Inhibiting activated protein kinases has revolutionized thyroid cancer therapy, offering a promising strategy in treating tumors refractory to radioactive iodine treatment or cytotoxic chemotherapies. However, despite satisfactory early responses, these drugs are not curative and most patients inevitably progress due to drug resistance. This review summarizes up-to-date knowledge on various mechanisms that thyroid cancer cells develop to bypass protein kinase inhibition and outlines strategies that are being explored to overcome drug resistance. Understanding how cancer cells respond to drugs and identifying novel molecular targets for therapy still represents a major challenge for the treatment of these patients.

Cell-Free DNA Analysis within the Challenges of Thyroid Cancer Management

Simple Summary

Liquid biopsy is a minimally invasive method that emerged as a new promising tool for improving diagnosis, risk stratification, follow-up, and treatment of cancer patients. To date, the majority of the research in the area of liquid biopsy has focused on plasma-based cell-free DNA as a potential surrogate for tumor DNA obtained from a tissue biopsy. In the last decades, breakthrough advancements have been performed in the knowledge of thyroid cancer genetics, and the role of molecular characterization in clinical decision-making is continuously rising, from diagnosis completion to the personalization of treatment approach. Hence, it is expectable for cell-free DNA to be applicable in thyroid cancer management. This review aims to investigate the cell-free DNA utility for thyroid cancer patients’ care.

Abstract

Thyroid cancer is the most frequent endocrine malignancy with an increasing incidence trend during the past forty years and a concomitant rise in cancer-related mortality. The circulating cell-free DNA (cfDNA) analysis is a patient’s friendly and repeatable procedure allowing to obtain surrogate information about the genetics and epigenetics of the tumor. The aim of the present review was to address the suitability of cfDNA testing in different forms of thyroid cancer, and the potential clinical applications, as referred to the clinical weaknesses. Despite being limited by the absence of standardization and by reproducibility and validity issues, cfDNA assessment has great potential for the improvement of thyroid cancer management. cfDNA may support the pre-surgical definition of thyroid nodules by complementing invasive thyroid fine needle aspiration cytology. In addition, it may empower risk stratification and could be used as a biomarker for monitoring the post-surgical disease status, both during active surveillance and in the case of anti-tumor treatment.

Anaplastic Thyroid Cancer: New Horizons and Challenges

Anaplastic thyroid cancer (ATC) remains one of the most aggressive and deadliest malignancies. Traditionally, treatment consisted of cytotoxic chemotherapy and radiation therapy, with or without surgery, although a large proportion of patients were often directed toward palliative/hospice care. In the past decade, significant advances have been made through the advent of targeted therapies and immunotherapy. For patients with targetable disease and considerable treatment response, surgery and other multidisciplinary adjuvant therapies can now be considered. Overall, the era of untreatable ATC is progressively being replaced by highly personalized multidisciplinary therapies, actively shifting the treatment pendulum of this disease.

Efficacy and safety of larotrectinib in patients with TRK fusion-positive thyroid carcinoma

OBJECTIVE

Larotrectinib is a highly selective tropomyosin receptor kinase (TRK) inhibitor with demonstrated efficacy across various TRK fusion-positive solid tumours. We assessed the efficacy and safety of larotrectinib in patients with TRK fusion-positive thyroid carcinoma (TC).

METHODS

We pooled data from three phase I/II larotrectinib clinical trials (NCT02576431, NCT02122913, and NCT02637687). The primary endpoint was the investigator-assessed objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors v1.1. Secondary endpoints included duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety. Data cut-off: July 2020.

RESULTS

Twenty-nine patients (median age: 60; range: 6-80) with TRK fusion-positive TC were treated. Tumour histology was papillary (PTC) in 20 (69%) patients, follicular (FTC) in 2 (7%), and anaplastic (ATC) in 7 (24%) patients. Among 28 evaluable patients, ORR was 71% (95% CI: 51-87); best responses were complete response in 2 (7%) patients, partial response in 18 (64%), stable disease in 4 (14%), progressive disease in 3 (11%), and undetermined in 1 (4%) due to clinical progression prior to the first post-baseline assessment. ORR was 86% (95% CI: 64-97) for PTC/FTC and 29% (95% CI 4-71) for ATC. Median time to response was 1.87 months (range 1.64-3.68). The 24-month DoR, PFS, and OS rates were 81, 69, and 76%, respectively. Treatment-related adverse events were mainly grades 1-2.

CONCLUSION

In TRK fusion-positive TC, larotrectinib demonstrates rapid and durable disease control and a favourable safety profile in patients with advanced disease requiring systemic therapy.

SIGNIFICANCE STATEMENT

NTRK gene fusions are known oncogenic drivers and have been identified in various histologies of thyroid carcinoma, most commonly in papillary thyroid carcinoma. This is the first publication specifically studying a TRK inhibitor in a cohort of TRK fusion-positive thyroid carcinoma patients. In the current study, the highly selective TRK inhibitor larotrectinib showed durable antitumour efficacy and a favourable safety profile in patients with TRK fusion-positive thyroid carcinoma. Our findings show that patients with advanced non-medullary thyroid carcinoma who may require systemic therapy could be considered for testing for gene fusions by next-generation sequencing.

Emerging Biomarkers in Thyroid Practice and Research

Simple Summary

Tumor biomarkers are molecules at genetic or protein level, or certain evaluable characteristics. These help in perfecting patient management. Over the past decade, advanced and more sensitive techniques have led to the identification of many new biomarkers in the field of oncology. A knowledge of the recent developments is essential for their application to clinical practice, and furthering research. This review provides a comprehensive account of such various markers identified in thyroid carcinoma, the most common endocrine malignancy. While some of these have been brought into use in routine patient management, others are novel and need more research before clinical application.

Abstract

Thyroid cancer is the most common endocrine malignancy. Recent developments in molecular biological techniques have led to a better understanding of the pathogenesis and clinical behavior of thyroid neoplasms. This has culminated in the updating of thyroid tumor classification, including the re-categorization of existing and introduction of new entities. In this review, we discuss various molecular biomarkers possessing diagnostic, prognostic, predictive and therapeutic roles in thyroid cancer. A comprehensive account of epigenetic dysregulation, including DNA methylation, the function of various microRNAs and long non-coding RNAs, germline mutations determining familial occurrence of medullary and non-medullary thyroid carcinoma, and single nucleotide polymorphisms predisposed to thyroid tumorigenesis has been provided. In addition to novel immunohistochemical markers, including those for neuroendocrine differentiation, and next-generation immunohistochemistry (BRAF V600E, RAS, TRK, and ALK), the relevance of well-established markers, such as Ki-67, in current clinical practice has also been discussed. A tumor microenvironment (PD-L1, CD markers) and its influence in predicting responses to immunotherapy in thyroid cancer and the expanding arena of techniques, including liquid biopsy based on circulating nucleic acids and plasma-derived exosomes as a non-invasive technique for patient management, are also summarized.

Bibliometric Insights in Advances of Anaplastic Thyroid Cancer: Research Landscapes, Turning Points, and Global Trends

Background

Thyroid cancers are the most common endocrine malignancies with a dramatic increase in incidences. Anaplastic thyroid cancer is a rare but deadly form among thyroid cancers. To better understand of this field, we assessed the global scientific outputs and tried to depict its overview via bibliometric methods.

Methods

Approximately 1,492 science publications published between 1997 and 2020 were included by systematic retrieval in the WoS database. The general information of them was characterized, and the developmental skeleton and research frontiers were explored.

Results

The article number in this field has been increasing in the past 24 years. North America, East Asia, and Western Europe have reached remarkable achievements. Mutations of BARF and TERT and their downstream pathways have attracted researchers’ attention, where genetic diagnosis provides new clinical insight and several targeted therapeutic approaches have been on the clinical trial.

Conclusions

Numerous efforts have been made to figure out gene expression reprogramming of anaplastic thyroid cancer and key mechanism in driving its dedifferentiation, invasion and migration process. Targeted therapy, immunotherapy, and systematic combination therapy are the recent current research hotspots. These results provide insightful clues for the funding direction and the potential breakthrough direction of the anaplastic thyroid cancer study.

Preliminary Study on the Relationship of BRAF Mutations with the Outcome of the First 131I Radiotherapy and Malignant Biological Characteristics in Papillary Thyroid Carcinoma

Objective

To investigate the relationship of BRAF mutation with the outcome of the first postoperative ¹³¹I treatment and malignant biological characteristics in papillary thyroid carcinoma (PTC).

Methods

Thirty-three patients with PTC who underwent their first ¹³¹I treatment after total thyroidectomy were enrolled in this study. BRAF mutation in postoperative tumor tissue and circulating tumor DNA (ctDNA) in peripheral blood at the time of ¹³¹I treatment were detected. According to the status of BRAF mutation, all patients were divided into 2 groups in each category of tumor tissues and ctDNA, respectively: 1) BRAF mutation, 2) BRAF wild-type. The Fisher’s exact test was performed to analyze the relationship of BRAF mutation in either tumor tissue or ctDNA with the outcome of the first ¹³¹I treatment and malignant characteristics of PTC.

Results

BRAF mutation was detected in tumor tissues in 25 patients (25/33,75.8%), and all the patients had single mutation site. In ctDNA, BRAF mutation was detected in 5 patients (5/33, 15.2%), and all the patients had single mutation site. In both tumor tissues and ctDNA, BRAF mutation showed no relationship with the outcome of first ¹³¹I treatment and the malignant biological characteristics (P>0.05).

Conclusion

The value of BRAF mutation alone might be limited in predicting therapeutic outcome of the first ¹³¹I treatment in PTC. No definitive relevance was found between BRAF mutation and malignant biological features in PTC.

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.

Translational Utility of Liquid Biopsies in Thyroid Cancer Management

Liquid biopsies are a novel technique to assess for either circulating tumor cells (CTC) or circulating tumor DNA (ctDNA and microRNA (miRNA)) in peripheral blood samples of cancer patients. The diagnostic role of liquid biopsy in oncology has expanded in recent years, particularly in lung, colorectal and breast cancer. In thyroid cancer, the role of liquid biopsy in either diagnosis or prognosis is beginning to translate from the lab to the clinic. In this review, we describe the evolution of liquid biopsies in detecting CTC, ctDNA and miRNA in thyroid cancer patients, together with its limitations and future directions in clinical practice.

Oncogenic Mutations in PI3K/AKT/mTOR Pathway Effectors Associate with Worse Prognosis in BRAFV600E -Driven Papillary Thyroid Cancer Patients

PURPOSE

The extent to which routine genomic sequencing can identify relevant secondary genomic alterations among BRAF^V600E -mutant papillary thyroid carcinoma (PTC) is unknown. Such markers would prove highly valuable for prognostic purposes.

EXPERIMENTAL DESIGN

We reviewed clinicopathologic data of 225 patients with BRAF^V600E -mutant PTC and integrated them with genomic data derived from targeted next-generation sequencing (NGS) on tumor specimens. We defined patient subgroups based on bona fide secondary oncogenic events (separate from BRAF^V600E ) and compared their clinical features and outcomes with those without additional oncogenic alterations.

RESULTS

Additional oncogenic alterations were identified in 16% of tumors. Patients in the "BRAF+additional mutations" group were more likely to be at high American Thyroid Association (ATA) risk of recurrence (48.6% vs. 17.6%; P = 0.0009), had larger baseline tumor (2.7 vs. 1.9 cm; P = 0.0005) and more advanced stage at presentation (14.3% vs. 1.1% stage 4; P < 0.0001). Importantly, over a 65-month follow-up, disease-specific mortality (DSM) was increased when additional mutations were identified (13.8% vs. 1.4% in the BRAF-only group; P = 0.005). Separately, we identified a subcluster of patients harboring oncogenic mutations in key effectors of the PI3K/AKT/mTOR pathway, which were independently associated with DSM (OR = 47.9; 95% confidence interval, 3.5-1,246.5; P = 0.0043).

CONCLUSIONS

Identification of additional PIK3/AKT/mTOR alterations in patients with BRAF^V600E -mutant PTC provides important and actionable prognostic risk stratification. These data support genomic profiling of PTC tumors to inform prognosis and clinical strategy.