The Prognostic Implications from Molecular Testing of Thyroid Cancer

Management of Small Papillary Thyroid Cancers

Thyroid cancer is the most common endocrine malignancy. With increasing imaging utilization, there has been an increase in the recognition of small, indolent cancers that would otherwise go undiagnosed. Historically, the surgical recommendation for all patients with thyroid cancer was a total thyroidectomy. However, over the last 20 years, there have been numerous studies evaluating the de-escalation of interventions for low-risk thyroid cancers, transitioning from total thyroidectomy to thyroid lobectomy or active surveillance when indicated. Here, we review the current literature and recommendations with each of these treatment options.

Advances in Molecular Profiling and Their Potential Influence on the Extent of Surgery in Well-Differentiated Thyroid Carcinoma (WDTC)

Thyroid cancer surgery has evolved dramatically with advances in our understanding of the biological behaviour of WDTC. Molecular profiling is shedding light on the subset that may behave aggressively. In an era when thyroid cancer management is becoming increasingly conservative, decision making regarding the extent of surgery must be objectively guided by molecular markers. The aim of the present article is to summarise the current published literature and provide possible practice recommendations. An online search for relevant published articles was performed using several databases. Title, abstract, and full-text screening, along with data extraction, was performed by two independent reviewers after the inclusion and exclusion criteria were defined. A total of 1241 articles were identified, and 82 relevant articles were extracted and scrutinised. BRAF V600E and TERT promoter mutations were found to be associated with an increased risk of disease recurrence and distant metastases. Several other mutations have been identified that enhance disease aggressiveness (such as RET/PTC, PTEN, and TP53). One of the most important determinants of the outcome in WDTC is the extent of surgical resection. The evolution of molecular testing has reached a stage of personalised incorporation into surgical practice. Guidelines for molecular testing and surgery in WDTC will need to be clearly defined, arguably representing the next chapter in the management of the disease.

Effect of Having Concurrent Mutations on the Degree of Aggressiveness in Patients with Thyroid Cancer Positive for TERT Promoter Mutations

This study aimed to examine whether concurrent mutations with a TERT promoter mutation are associated with a greater likelihood of more aggressive disease than a TERT promoter mutation alone. The medical records of 1477 patients who underwent thyroid surgery at two tertiary hospitals between 2017 and 2022 were reviewed. Twenty-four patients had TERT promoter mutations based on molecular profile testing. Clinicodemographic data, mutational profiles, and histopathological features were assessed. Descriptive analysis, Fisher's exact test, and binary logistic regression were performed. Seven patients had single-gene TERT promoter mutations, and 17 had concurrent mutations, including BRAF V600E, HRAS, NRAS, PIK3CA, and EIF1AX. The overall prevalence of malignancy was 95.8%, of which 78.3% were aggressive thyroid cancers. There was a statistically significant association between concurrent mutations and disease aggressiveness. The odds of having aggressive disease were 10 times higher in patients with a TERT promoter mutation and a concurrent molecular alteration than in those with a TERT promoter mutation alone. This is an important finding for thyroid specialists to consider when counseling patients concerning risk stratification and management options.

[Accuracy of two thyroid imaging, reporting and data systems for differential diagnosis of benign and malignant thyroid nodules]

OBJECTIVE

To compare the accuracy of two widely used thyroid imaging, reporting and data systems (TI-RADS), namely ACR TI-RADS and Kwak TI-RADS, in the differential diagnosis of benign and malignant thyroid nodules.

METHODS

We reviewed the data of 350 thyroid nodules with definite diagnoses by surgical histopathology (n=144, 41.14%) or fine needle aspiration (FNA) cytopathology (n=206, 58.86%). The nodules were graded using ACR TI-RADS and Kwak TI-RADS based on the ultrasound images, and the diagnostic accuracy of these two systems was evaluated by the area under the receiveroperating characteristic curve (AUC).

RESULTS

The AUCs of ACR TI-RADS and Kwak TI-RADS were both 0.879. For a differential diagnosis of the thyroid nodules, ACR TI-RADS had a diagnostic sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, Youden's index and accuracy of 77.3%, 89.1%, 83.0%, 85.1%, 7.101, 0.255, 27.848, 0.664 and 0.843, respectively, with an optimal threshold of TR5, as compared with 84.8%, 84.0%, 78.3%, 89.0%, 5.283, 0.181, 29.265, 0.688 and 0.843, respectively, of Kwak TI-RADS, which had an optimal threshold of 4c.

CONCLUSIONS

Both ACR TI-RADS and Kwak TI-RADS have good performance for differential diagnosis of thyroid nodules, but ACR TI-RADS has a higher specificity and a lower sensitivity compared with Kwak TI-RADS.

Absence of RET/PTC1 rearrangement in a sample of Colombian individuals with papillary thyroid carcinoma

Introduction: Papillary thyroid carcinoma is the most common endocrine neoplasm; therefore, markers with possible prognostic utility have been evaluated.Objective: To analyze the presence of RET/PTC1 rearrangement, lymphocytic thyroiditis and associated clinical features in patients with papillary thyroid cancer treated at the Hospital de San José in Bogotá, Colombia.Materials and methods: Clinical records of patients with complete thyroidectomy and diagnosis of papillary cancer were retrospectively identified. RNA was extracted from tumor tissue, and cDNA was obtained using inverse transcriptase to detect the rearrangement of the RET/PTC1 gene by means of qPCR.Results: 55 patients with papillary thyroid cancer were selected; 93% were females, and the mean age was 45.8 years. The most frequent histological variant was classic (49%). A relationship was found between lymphocytic thyroiditis and the number of positive nodes in segments other than central draining, as well as thyroiditis and antithyroid antibody value. No RET/PTC1 rearrangement expression was found.Conclusions: A relationship between lymphocytic thyroiditis and the number of positive nodes in segments other than central draining was found. Other molecular markers should be searched to differentiate the prognosis of these patients.

Rationales for the Use of Cancer Stem Cells Markers in the Staging of Papillary Thyroid Carcinoma

Fine needle aspiration biopsy (FNAB) is a standard procedure for the detection of thyroid nodules malignancy, yet 10-25% of the sample diagnosed may go undetermined or suspicious. The utility of cancer stem cell markers (CSCM) as a differential diagnosis molecular marker in nodules of suspicious decision in FNAB was hypothesized. Papillary thyroid carcinoma (PTC) and thyroid fibroadenoma (TFA) samples were selected to test the hypothesis. The samples employed in this study were from patients who had thyroid hyperplasia and a suspicious or undetermined diagnosis by FNAB. The patient underwent a successful thyroidectomy at Al-Yarmouk Teaching Hospital in Baghdad between January 2015 and December 2017. All nodule samples underwent a systematic histopathological examination after resection. Tumors diagnosed as PTC and those diagnosed as fibroadenoma (TFA) were selected for this study. Collectively 39 PTC and 11 TFA nodules were included. Quantitative reverse transcriptase real-time PCR (qRT-PCR) and immunohistochemistry (IHC) were used to determine levels of mRNA and proteins of CSCM ALDH1A1, CD44, ABCG2, and Oct3/4 in both types of tumors were used. This study revealed that the expression levels of CSCM were significantly increased in PTC tissues when compared to benign tissues and the positive correlation was found between the CSCM expression levels and tumor stage, size, and gender. In conclusion, for a more precise diagnosis, we suggest these markers be included in what is currently available to characterize malignancy from what is not in thyroid cancer, as well as for the staging process of PTC.

Extent of Surgery for Low-Risk Differentiated Thyroid Cancer

Although the incidence of thyroid cancer is increasing, survival remains unchanged. Due to concern for overtreatment, surgical management of thyroid cancer has evolved. Papillary thyroid microcarcinoma measuring 1 cm or smaller are considered very low risk and can be managed with either thyroid lobectomy or active surveillance. Total thyroidectomy is no longer recommended for these cancers unless there is evidence of metastasis, local invasion, or aggressive disease. Recommendations for low-risk differentiated thyroid cancer measuring 1 cm to 4 cm remain controversial. This article explores the controversies over the extent of surgery for patients with very low-risk and low-risk differentiated thyroid cancer.

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.

The role of molecular diagnostic testing in the management of thyroid nodules

INTRODUCTION

Fine needle aspiration (FNA) with cytologic examination remains the standard of care for investigation of thyroid nodules. However, as many as 30% of FNA samples are cytologically indeterminate for malignancy, which confounds clinical management. To reduce the burden of repeat diagnostic testing and unnecessary surgery, there has been extensive investigation into molecular markers that can be detected on FNA specimens to more accurately stratify a patient's risk of malignancy. Areas covered: In this review, the authors discuss recent evidence and progress in molecular markers used in the diagnosis of thyroid cancer highlighting somatic gene alterations, molecular technologies and microRNA analysis. Expert commentary: The goal of molecular markers is to improve diagnostic accuracy and aid clinicians in the preoperative management of thyroid lesions. Modalities such as direct mutation analysis, mRNA gene expression profiling, next-generation sequencing, and miRNA expression profiling have been explored to improve the diagnostic accuracy of thyroid nodule FNA. Although no perfect test has been discovered, molecular diagnostic testing has revolutionized the management of thyroid nodules.