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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. [ABSTRACT FROM AUTHOR]

B Dear Editor: b Advanced thyroid cancers may invade recurrent laryngeal nerve (RLN) through direct tumor extension or lymph node metastasis, resulting in vocal fold paralysis (VFP) which impacts patient's quality of life, affects the resectability when operating on the contralateral (functional) side due to the significant risk for bilateral VFP during surgery and the potential need for tracheotomy, and significantly impacts the surgical strategy.[1],[2] Many patients will be understandably hesitant to undergo surgery that involves permanent tracheotomy.[3] Both unilateral or bilateral VFP have a negative impact on a patient's quality of life and general health.[4],[5] While preoperative VFP is highly suggestive of RLN invasion, normal voice or laryngeal exam does not exclude RLN invasion at surgery. I BRAF SP V600E sp i mutations were detected in all seven patients (100%), I TERT i promoter mutations were detected in four patients (57.1%), I PIK3CA i mutations in two patients (28.6%), and I TP53 i mutations in two patients (28.6%), Supplementary Table S1. Overall, the median number of cycles of all neoadjuvant therapy received per patient regardless of therapy type was 4 cycles/patient. [Extracted from the article]

Background: BRAFV600E is the most common mutation in papillary thyroid carcinoma (PTC) and can be associated with aggressive disease. Previously, a highly sensitive blood RNA-based BRAFV600E assay was reported. The objective of this study was to assess the correlation of BRAFV600E circulating tumor RNA levels with surgical and medical treatment. Methods: Circulating BRAFV600E levels were assessed in (i) a murine model of undifferentiated (anaplastic) thyroid carcinoma with known BRAFV600E mutation undergoing BRAFV600E-inhibitor (BRAFi) treatment, and (ii) in 111 patients enrolled prior to thyroidectomy (n = 86) or treatment of advanced recurrent or metastatic PTC (n = 25). Blood samples were drawn for BRAFV600E analysis before and after treatment. Testing characteristics were assessed and positivity criteria optimized. Changes in blood BRAFV600E values were assessed and compared to clinical characteristics and response to therapy. Results: In a murine model of anaplastic thyroid carcinoma with BRAFV600E mutation, blood BRAFV600E RNA correlated with tumor volume in animals treated with BRAFi. In tissue BRAFV600E-positive (n = 36) patients undergoing initial surgery for PTC, blood BRAFV600E levels declined postoperatively (median 370.0-178.5 fg/ng; p = 0.002). In four patients with metastatic or poorly differentiated thyroid carcinoma receiving targeted therapies, blood BRAFV600E declined following therapy and corresponded with radiographic evidence of partial response or stable disease. Conclusions: This study shows the correlation of blood BRAFV600E levels in response to treatment in both an established animal model of thyroid cancer and in patients with BRAFV600E-positive tumors with all stages of disease. This assay represents an alternative biomarker in patients with positive thyroglobulin antibodies, and tumors, which do not express thyroglobulin. [ABSTRACT FROM AUTHOR]