Alterations In Thyroid Carcinoma Research Articles

FGFR Alterations in Thyroid Carcinoma: A Novel Class of Primary Drivers with Significant Therapeutic Implications and Secondary Molecular Events Potentially Mediating Resistance in Thyroid Malignancy

<i>FGFR</i> Alterations in Thyroid Carcinoma: A Novel Class of Primary Drivers with Significant Therapeutic Implications and Secondary Molecular Events Potentially Mediating Resistance in Thyroid Malignancy

FGFR Alterations in Thyroid Carcinoma: A Novel Class of Primary Drivers with Significant Therapeutic Implications and Secondary Molecular Events Potentially Mediating Resistance in Thyroid Malignancy.

Background: Diagnostic classification of thyroid malignancy is primarily accomplished through examination of histomorphological features and may be substantiated and clarified by molecular data. Individual molecular drivers show relatively robust and specific associations with histological subtypes of thyroid malignancy, including BRAF sequence variants and kinase gene fusions in papillary thyroid carcinoma, predominantly RAS variants in follicular-patterned neoplasia, and additional "late" mutations affecting TERT promoter, TP53, and the PI3K/AKT/PTEN pathway in high-grade malignancies. Given the oncogenic role of FGFR, particularly FGFR1-3, the goal of this study was to explore the role of FGFR in thyroid carcinoma biology. Methods: We completed a multicenter retrospective observational study for thyroid carcinomas with pathogenic alterations in the FGFR gene family. We performed this study by querying the molecular data accumulated for thyroid carcinomas from each center. Results: Overall, 5030 sequenced thyroid malignancies were reviewed, yielding 17 tumors with FGFR alterations, including 11 where FGFR was the primary molecular driver and 6 where FGFR was a secondary pathogenic alteration, with a subset for which there was available clinical follow-up data. Of the 11 carcinomas with an FGFR driver, 9 were gene fusions involving FGFR2:VCL (4 tumors), TG::FGFR1 (3 tumors), FGFR2::CIT, and FGFR2::SHTN1, and the remaining 2 were driven by FGFR1 amplification. In the 6 tumors where a canonical driver of thyroid neoplasia was present (5 cases) or no clear primary driver was detected (1 case), sequencing detected secondary FGFR2 p.W290C, p.Y375C, and p.N549K, as well as FGFR1 p.N546K in the respective tyrosine kinase domains, some at subclonal variant allele frequencies. Conclusions: This study presents the first description of a collection of thyroid carcinomas grouped by primary driver alterations in FGFR, as well as a cohort of thyroid tumors with secondary alterations that potentially lead to tumor progression or resistance to targeted therapy. Given the availability of small molecular inhibitors targeting oncogenic FGFR, this study emphasizes the significant implications for patients from identification of FGFR alterations as they are currently under-recognized in the literature and, most importantly, have potential novel treatment options.

Stable thyroid cancer in a patient with thoracic aortic aneurysm and MYH11 variation.

We report the case of a male patient with papillary thyroid cancer, familial thoracic aortic aneurysm and dissection, and a variation in the MYH11 gene. Because of considerable tumor bulk in the neck that was not resectable, the patient underwent partial resection at age 14 years. Since then, the patient has received only suppressive thyroid hormone therapy. He is now 71 years old, which is 57 years after the initial resection. The patient received care at our institution from July 2009 to August 2019, during which we documented the stability of multiple calcified masses in the neck. Follow-up examinations at another institution from September 2019 to April 2023 also confirmed the stability of the masses. The underlying cause of this unusually long indolent course of the disease is unclear. Whether extensive tumor calcifications or the MYH11 sequence variation contributed to the disease course is also uncertain. Papillary thyroid cancer with neck metastases may, in some cases, be stable and remain asymptomatic for decades. If locoregional stability of papillary thyroid cancer is documented for many years, observation may be preferable to extensive neck surgery in selected cases. This is the first report of an MYH11 gene alteration and thoracic aortic aneurysm in a patient with papillary thyroid cancer with indolent neck metastases. Future studies of MYH11 gene alterations in thyroid carcinoma are needed.

Looking for RET alterations in thyroid cancer: clinical relevance, methodology and timing.

Thyroid carcinoma (TC) is a rare neoplasia of the endocrine system and account for about 2-3% of all human tumors. According to their cell origin and histological features, different histotypes of thyroid carcinoma are described. Genetic alterations involved in the pathogenesis of thyroid cancer have been described and it has been shown that alterations of the RET gene are common events in all TC hystotypes. Aim of this review is to give an overview of the relevance of RET alterations in TC and to provide indications, timing and methodologies, for RET genetic analysis. A revision of the literature has been performed and indications for the experimental approach for the RET analysis have been reported. The analysis of RET mutations in TC has a very important clinical relevance for the early diagnosis of the hereditary forms of MTC, for the follow-up of TC patients and for the identification of those cases that can benefit from a specific treatment able to inhibit the effect of mutated RET.

Anti-EGFR/BRAF-Tyrosine Kinase Inhibitors in Thyroid Carcinoma.

Alterations in significant genes located on chromosome 7 - including epidermal growth factor receptor (EGFR) and also v-Raf murine sarcoma viral oncogene homolog B (BRAF) as a mitogen-activated protein kinase (MAPK) - combined or not with numerical imbalances of the whole chromosome (aneuploidy-polysomy) are crucial genetic events involved in the development and progression of malignancies. Identification of EGFR/BRAF-dependent specific somatic mutations and other mechanisms of deregulation (i.e., amplification) is critical for applying targeted therapeutic approaches [tyrosine kinase inhibitors (TKIs] or monoclonal antibodies (mAbs). Thyroid carcinoma is a specific pathological entity characterized by a variety of histological sub-types. Follicular thyroid carcinoma (FTC), papillary thyroid carcinoma (PTC), medullary thyroid carcinoma (MTC), and anaplastic thyroid carcinoma (ATC) represent its main sub-types. In the current review, we explore the role of EGFR/BRAF alterations in thyroid carcinoma in conjunction with the corresponding anti-EGFR/BRAF TKI-based novel therapeutic strategies for patients with specific genetic signatures.

Editorial: The role of genetic alterations in thyroid carcinoma

Editorial: The role of genetic alterations in thyroid carcinoma

Characterization of genomic landscape using comprehensive circulating cell-free tumor DNA next generation sequencing in advanced thyroid carcinoma.

3045 Background: Availability of targeted therapies in thyroid carcinoma (TC) has challenged the conventional treatment algorithms and established urgency for timely identification of targetable genetic abnormalities. Tissue-based next generation sequencing (NGS) is often limited by tumor insufficiency and slow turn-around time. Plasma-based circulating tumor DNA (ctDNA) NGS overcomes these barriers and has been widely adopted across advanced-stage solid tumors. To date, plasma-based NGS characterization of genomic alterations in TC has not been determined. Herein, we profile potential actionable mutations detected via ctDNA in patients with advanced TC subtypes. Methods: A retrospective analysis of Guardant Health, Inc database was performed using the commercially available Guardant360 plasma-NGS test on advanced metastatic TC samples collected between 2016 and 2021. Patients with papillary TC (PTC), follicular TC (FTC), poorly differentiated TC (PDTC), medullary TC (MTC), and anaplastic TC (ATC) were clustered into four groups (G1: ATC, G2: PTC, FTC, and PDTC, G3: MTC, and G4: unspecified TC). The landscape of genetic alterations, frequencies of alterations in clinically relevant genes, and tumor mutation burden (TMB) were analyzed. Results: Of the 1,108 patients included, 47.1% were male. The median age was 65 years old (range 13-98), and 0.18% (n = 5) patients were under 18 years old. Alteration frequencies of selected, clinically relevant genes are demonstrated in the table below. TMB analysis was performed on 315 samples, and the mean TMB was higher in G1 compared to G2, G3, and G4 (p = 0.0029, 0.0826, and 0.0112, respectively). Conclusions: Plasma-based comprehensive NGS by Guardant360 may be utilized in patients with advanced metastatic TC for detecting clinically relevant genetic alterations for the selection of available targeted therapies, immunotherapy, or determination of the clinical trial eligibility. Future validation of the clinical utility by analysis of paired tumor and plasma samples is warranted. [Table: see text]

Resistance to Kinase Inhibitors in Poorly Differentiated and Anaplastic Thyroid Cancer: Preclinical In vitro Evidences

Poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) are rare but highly aggressive malignancies with an extremely short survival. Poor prognosis is due to their unlimited growth, invasion, migration and resistance to common anticancer therapies. Advances in understanding the molecular alterations in thyroid carcinomas led to development of new therapeutic strategies such as kinase inhibitors. Although several of these compounds have been approved by FDA and EMA for the treatment of radioactive-iodine refractory differentiated thyroid cancer (DTC) and medullary thyroid cancer (MTC), no significant clinical efficacy with targeted therapies have been observed in those patients. Herein, we review and summarize the preclinical In vitro evidences of mechanisms of resistance to kinase inhibitors currently used in PDTC and ATC patients.

Modeling Thyroid Cancer in the Mouse

Thyroid carcinomas, the most common endocrine tumors in humans, have an increasing incidence in the U.S. and worldwide. There are four major types of thyroid cancers: papillary, follicular, anaplastic, and medullary carcinomas. In recent years, significant progress has been made in the identification of genetic alterations in thyroid carcinomas, particularly, papillary and medullary thyroid cancers. Mouse models of thyroid cancer are valuable tools in elucidating molecular genetic changes underlying thyroid carcinogenesis and in identifying potential molecular targets for therapeutic intervention. Representative mouse models of papillary, follicular, and medullary carcinomas are reviewed here with particular emphasis on those for follicular thyroid carcinomas. Challenges for further development in the modeling of thyroid cancer will also be discussed.

Genetic alterations in thyroid carcinoma associated with familial adenomatous polyposis: clinical implications and suggestions for early detection.

Germ-line mutations of the adenomatous polyposis (APC) gene, responsible for familial adenomatous polyposis (FAP) were analyzed in 15 patients with FAP-associated papillary thyroid carcinomas: 13 had the mutation between codons 778 and 1309 (exon 15), 1 at codon 593 (exon 14), and 1 at codon 140 (exon 3). Therefore APC gene mutations clustered in the genomic area associated with congenital hypertrophy of the retinal pigment epithelium (CHRPE) (codons 463-1387). Ocular patches were documented in 12 patients. In particular, 4 of the 15 patients, all women with a mean age of 23.5 (range 20-32), were found during the study of 15 consecutive kindreds who had undergone systematic screening for extra-colonic manifestations. Three of them belonged to the same kindred and were asymptomatic. These four patients were also screened for loss of heterozygosity of APC in the thyroid tumoral tissue. No biallelic inactivation of the APC gene was found. In contrast, three of these four patients had activation of the ret-PTC oncogene. In particular, there was activation of the ret-PTC1 isoform, a chimeric gene resulting from fusion of a gene named H4 with the RET gene. On histologic examination, three of the four patients showed Hashimoto-like lymphocytic infiltration. Present data suggest that: (1) the incidence of FAP-associated thyroid cancer probably has been underestimated in the past; (2) intensive screening could detect a larger than expected number of thyroid carcinomas; (3) systematic screening is recommended in patients with ocular patches and genetic mutation in exon 15; (4) Hashimoto-like findings do not exclude carcinoma but are a frequent accompanying finding; (5) despite frequent multicentricity and early lymph node involvement, FAP-associated thyroid tumors seem to have an excellent prognosis, in particular those showing ret-PTC activation.

Genetic alterations in thyroid carcinomas and adenomas detected by restriction landmark genomic scanning

Alterations of genomic DNAs in 9 papillary thyroid carcinomas and 3 follicular thyroid adenomas were examined by restriction landmark genomic scanning, a 2-dimensional gel analysis that allows detection of deletions, amplifications and other rearrangements of genomic DNA. DNAs from both thyroid tumors and associated non-tumorous glandular tissues were cleaved with the restriction enzyme NotI end-labeled with P-32 and size-fractionated by 2-dimensional electrophoresis using HinfI in a second digestion. The altered spots in carcinomas and adenomas were compared with those in nontumorous samples. Five and 4 spots were commonly amplified in carcinomas and adenomas, respectively. One amplified spot was apparently specific only for carcinoma and was not detected in any of adenomas examined. In contrast, 12 spots reduced in intensity were frequently observed in tumors, although a subset of 5 were more sporadically affected in adenomas. The results indicate both common and distinct genetic abnormalities occurring in thyroid tumors, which may relate to the different biological behaviors of malignant and benign neoplasms.

Lack of p16/CDKN2 alterations in thyroid carcinomas.

Exons 1-3 of the p16/CDKN2 gene and exons 4-9 of the p53 gene were screened for mutations by single-strand conformation polymorphism (SSCP) analysis and direct sequencing of PCR-amplified DNA from human primary thyroid carcinomas and thyroid carcinoma cell lines. The samples included 21 papillary carcinomas, 2 undifferentiated carcinomas, 1 follicular carcinoma, 1 medullary carcinoma and 2 cell lines originating from thyroid undifferentiated carcinomas. No homozygous deletions and mutations in the p16/CDKN2 were observed in any of the primary tumors or cell lined. In contrast, one of the two undifferentiated carcinomas an both cell lines demonstrated point mutations in the p53 gene. These results that p16/CDKN2 gene alteration is not required for malignant transformation in the thyroid, while p53 gene mutations may play a role in the progression from differentiated to undifferentiated carcinoma.