Does Molecular Genotype Provide Useful Information in the Management of Radioiodine Refractory Thyroid Cancers? Results of a Retrospective Study

The value of preoperative molecular testing in the management of Bethesda V and Bethesda VI thyroid tumors

The incidence of thyroid cancer has increased over recent years due to the fact that several diagnostic tools, such as neck ultrasound and fine-needle aspiration, are being ever more widely adopted. Lately, another modality which might provide significant information preoperatively on the aggressiveness of a thyroid tumor, its prognosis, and its recurrence rate is molecular testing. We reviewed the literature with regard to the role of preoperative molecular testing in patients with Bethesda V and Bethesda VI thyroid nodules and its impact on choice of the optimal treatment strategy. Several molecular mutations and alterations are associated with thyroid cancer and its biological behavior, such as BRAF-V600E, RET, and TERT promoter. Although the value of preoperative molecular testing for indeterminate nodules (Bethesda III and Bethesda IV) have been analyzed in numerous studies, the impact of preoperative molecular testing on Bethesda V and Bethesda VI thyroid nodules is not adequately described in the current literature. The preoperative recognition of specific molecular mutations, such as BRAFV600E and TERT promoter mutation, might provide more individualized management for thyroid cancer patients by altering the surgical approach and the extent of surgery for patients diagnosed with a more aggressive or iodine-resistant subtype of thyroid cancer.Thyroid cancer is characterized by multiple genetic mutations and alterations and, as a result, preoperative molecular testing of malignant nodules could be a very useful tool for surgeons, enabling them to decide on the most appropriate surgical approach for each patient.

Emerging drugs for the treatment of radioactive iodine refractory papillary thyroid cancer

INTRODUCTION

The most frequent radioactive (RAI) refractory thyroid cancers are papillary thyroid carcinoma, followed by poorly differentiated thyroid carcinoma. They are rare and lethal. In recent years, significant therapeutic progress has been achieved.

AREAS COVERED

This paper offers insights on refractoriness to RAI treatment and the optimization of treatment initiation and treatment choice. Clinical trials performed with anti-angiogenic kinase inhibitors and with targeted inhibitors in patients with BRAF, RAS mutation or RET, TRK or ALK fusion are discussed.

EXPERT OPINION

These treatments provide high response rates. Anti-angiogenic kinase inhibitors improve median progression-free-survival; however, their benefit in terms of overall survival has been shown in only few subsets of patients. Treatment sequencing is challenging; in the absence of targetable abnormality, lenvatinib should be used as first line treatment. Options for second line treatment include lenvatinib (if not given at first line), cabozantinib or the addition of an anti-checkpoint antibody. In patients with a targetable abnormality, specific inhibitors, might be used as first line treatment and lenvatinib as second line or vice-versa. Further studies are needed, based on documented genomic and immunologic characteristics of the tumor to assess the potential role of combination and redifferentiation therapy.

Prognostic and Therapeutic Role of Angiogenic Microenvironment in Thyroid Cancer

Simple Summary

Angiogenesis is an essential event for the progression of solid tumors and is promoted by angiogenic cytokines released in the tumor microenvironment by neoplastic and stromal cells. Over the last 20 years, the role of the microenvironment and the implication of several angiogenic factors in tumorigenesis of solid and hematological neoplasms have been widely studied. The tumor microenvironment has also been well-defined for thyroid cancer, clarifying the importance of angiogenesis in cancer progression, spread, and metastasis. Furthermore, recent studies have evaluated the association of circulating angiogenic factors with the clinical outcomes of differentiated thyroid cancer, potentially providing noninvasive, low-cost, and safe tests that can be used in screening, diagnosis, and follow-up. In this review, we highlight the mechanisms of action of these proangiogenic factors and their different molecular pathways, as well as their applications in the treatment and prognosis of thyroid cancer.

Abstract

Thyroid cancer is the most common endocrine malignancy, with a typically favorable prognosis following standard treatments, such as surgical resection and radioiodine therapy. A subset of thyroid cancers progress to refractory/metastatic disease. Understanding how the tumor microenvironment is transformed into an angiogenic microenvironment has a role of primary importance in the aggressive behavior of these neoplasms. During tumor growth and progression, angiogenesis represents a deregulated biological process, and the angiogenic switch, characterized by the formation of new vessels, induces tumor cell proliferation, local invasion, and hematogenous metastases. This evidence has propelled the scientific community’s effort to study a number of molecular pathways (proliferation, cell cycle control, and angiogenic processes), identifying mediators that may represent viable targets for new anticancer treatments. Herein, we sought to review angiogenesis in thyroid cancer and the potential role of proangiogenic cytokines for risk stratification of patients. We also present the current status of treatment of advanced differentiated, medullary, and poorly differentiated thyroid cancers with multiple tyrosine kinase inhibitors, based on the rationale of angiogenesis as a potential therapeutic target.

Correlation between F18-FDG PET/CT Imaging and BRAF V600E Genetic Mutation for the Early Assessment of Treatment Response in Papillary Thyroid Cancers

In thyroid neoplastic pathology, the BRAF V600E mutation is shown to be involved in the oncogenesis of papillary thyroid cancer and its subtypes. The purpose of this study is to evaluate the correlation between the mutation of the BRAF V600E oncogene and the pathological standardized uptake values (SUV) at the F18-fluorodeoxyglucose (F18-FDG) positron emission tomography/computed tomography (PET/CT) evaluation, for a group of 20 patients with radically treated (total thyroidectomy and radioiodine therapy) papillary thyroid cancer, with subclinical persistent disease, at 6 months after the initial treatment. We analyzed the correlations between the values of SUV and the presence of the BRAF mutation as well with other prognostic factors such as stage, age, specific tumor markers (thyroglobulin and anti-thyroglobulin), extrathyroid extension, the presence of metastatic lymph nodes or distant metastasis. The value of SUV in the case of BRAF+ (positive) patients was higher than in the negative ones, but without statistical significance, thus, the values of the SUV cannot be a predictable factor for the presence of the genetic mutation. There was a statistically significant correlation in BRAF+ subgroup between the SUV values and the positive resection limit following surgery, showing a higher SUV value in the PET/CT evaluation. No correlation was observed between the aforementioned prognostic factors involved in papillary thyroid cancer and the BRAF V600E mutation.

Current Advances in Thyroid Cancer Management. Are We Ready for the Epidemic Rise of Diagnoses?

A rising incidence of thyroid cancers (TCs) mainly small tumors, observed during recent years, lead to many controversies regarding treatment strategies. TCs represent a distinct molecular background and clinical outcome. Although in most cases TCs are characterized by a good prognosis, there are some aggressive forms, which do not respond to standard treatment. There are still some questions, which have to be resolved to avoid dangerous simplifications in the clinical management. In this article, we focused on the current advantages in preoperative molecular diagnostic tests and histopathological examination including noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). We discussed the controversies regarding the extent of thyroid surgery and adjuvant radioiodine therapy, as well as new treatment modalities for radioiodine-refractory differentiated thyroid cancer (RR-DTC). Considering medullary thyroid cancer (MTC), we analyzed a clinical management based on histopathology and RET (ret proto-oncogene) mutation genotype, disease follow-up with a special attention to serum calcitonin doubling time as an important prognostic marker, and targeted therapy applied in advanced MTC. In addition, we provided some data regarding anaplastic thyroid cancer (ATC), a highly lethal neoplasm, which lead to death in nearly 100% of patients due to the lack of effective treatment options.

Therapeutic options in papillary thyroid carcinoma: current guidelines and future perspectives

The treatment of papillary thyroid cancer is now based on individual patient risk and response to therapies. Molecular techniques are increasingly being used to risk stratify and to guide therapeutic decisions. There have been advances in the treatment of local disease through surgery or radioiodine. Directed techniques can target metastatic disease including bisphosphonates, radiofrequency ablation or radiotherapy. Systemic therapies such as tyrosine kinase inhibitors show great promise although such treatment must be individualized. Future therapies will target treating radioiodine refractory disease.