Genetic trio of BRAF and TERT alterations and rs2853669TT in papillary thyroid cancer aggressiveness

High Prevalence of TBC1D12 5'UTR Mutations in Anaplastic Thyroid Cancer

Background: Anaplastic thyroid cancer (ATC) is a rare but one of the most lethal types of human cancer. Although increasing evidence demonstrated that ATC tumors had a high mutation burden, little is known about the aberrancy of the noncoding genome of ATC except the well-investigated telomerase reverse transcriptase (TERT) promoter mutations. Methods: The mutational statuses of TBC1D12 5' untranslated region (5'UTR), GPR126 intron 6, SDHD and PLEKHS1 promoters, as well as the TERT promoter and BRAFV600E mutations were determined using Sanger sequencing in 28 patients with ATC (19 women and 9 men) with a median (interquartile range) age of 64 (55-71) years, 14 thyroid cancer cell lines and a normal thyroid cell line. The prevalence of TBC1D12 5'UTR mutations in papillary thyroid cancer (PTC) and their association with clinicopathologic characteristics were explored by analyzing The Cancer Genome Atlas thyroid cancer dataset. Results: The noncoding mutations in TERT, SDHD and PLEKHS1 promoters, TBC1D12 5'UTR, and GPR126 intron 6 were collectively found in 82.1% (23/28) of ATC samples. Specifically, TERT promoter mutations were detected in 22 (78.6%) samples; GPR126 intron mutations were detected in 2 (7.1%) samples; and both SDHD and PLEKHS1 promoter mutations were detected in 1 (3.6%) ATC sample. Two hotspot mutations in TBC1D12 5'UTR were observed in 14 of 28 (50%) ATCs, 7 of 492 (1.4%) PTCs, and 1 cell line derived from ATC. TBC1D12 5'UTR mutations were significantly associated with older age at diagnosis (60 vs. 46 for wild type, p = 0.003), pathological T3/T4 stage (85.7% vs. 37.7%, p = 0.010), and advanced tumor stages (85.7% vs. 32.5%, p = 0.006) in PTC. Conclusions: This preliminary study for the first time showed a high prevalence of TBC1D12 5'UTR mutations in ATC and indicated an association between TBC1D12 mutation and aggressive characteristics of PTC, which needs to be confirmed in large cohort studies.

Molecular Pathology of Thyroid Tumors: Essential Points to Comprehend Regarding the Latest WHO Classification

In 2022, the new WHO Classification of Endocrine and Neuroendocrine Tumors, Fifth Edition (beta version) (WHO 5th), was published. Large-scale genomic analyses such as The Cancer Genome Atlas (TCGA) have revealed the importance of understanding the molecular genetics of thyroid tumors. Consequently, the WHO 5th was fundamentally revised, resulting in a systematic classification based on the cell of origin of tumors and their clinical risk. This paper outlines the following critical points of the WHO 5th. 1. Genetic mutations in follicular cell-derived neoplasms (FDNs) highlight the role of mutations in the MAP kinase pathway, including RET, RAS, and BRAF, as drivers of carcinogenesis. Differentiated thyroid cancers such as follicular thyroid carcinoma (FTC) and papillary thyroid carcinoma (PTC) have specific genetic alterations that correlate with morphological classifications: RAS-like tumors (RLTs) and BRAF p.V600E-like tumors (BLTs), respectively. 2. The framework for benign lesions has been revised. The WHO 5th introduces a new category: "developmental abnormalities". Benign FDNs comprise "thyroid follicular nodular disease", follicular thyroid adenoma (FTA), FTA with papillary architecture, and oncocytic adenoma (OA). "Hürthle cell adenoma/carcinoma" is renamed oncocytic adenoma/carcinoma of the thyroid (OA/OCA), which can be distinguished from FTA/FTC by its unique genetic background. 3. Low-risk tumors include NIFTP, TT-UMP, and HTT, and they have an extremely low malignant potential or an uncertain malignant potential. 4. PTC histological variants are reclassified as "subtypes" in the WHO 5th. 5. The concept of high-grade carcinomas is introduced, encompassing poorly differentiated thyroid carcinoma (PDTC), differentiated high-grade thyroid carcinoma (DHGTC), and high-grade medullary thyroid carcinoma (MTC). 6. Squamous cell carcinoma is included in anaplastic thyroid carcinoma (ATC) in the WHO 5th due to their shared genetic and prognostic features. 7. Other miscellaneous tumors are categorized as salivary-gland-type carcinomas of the thyroid, thyroid tumors of uncertain histogenesis, thymic tumors within the thyroid, and embryonal thyroid neoplasms. The WHO 5th thus emphasizes the importance of classifying tumors based on both genetic abnormalities and histomorphology. This approach aids in achieving accurate pathological diagnosis and facilitates the early selection of appropriate treatment options, including molecular targeted therapies.

Advances in targeted therapy and biomarker research in thyroid cancer

Driven by the intricacy of the illness and the need for individualized treatments, targeted therapy and biomarker research in thyroid cancer represent an important frontier in oncology. The variety of genetic changes associated with thyroid cancer demand more investigation to elucidate molecular details. This research is clinically significant since it can be used to develop customized treatment plans. A more focused approach is provided by targeted therapies, which target certain molecular targets such as mutant BRAF or RET proteins. This strategy minimizes collateral harm to healthy tissues and may also reduce adverse effects. Simultaneously, patient categorization based on molecular profiles is made possible by biomarker exploration, which allows for customized therapy regimens and maximizes therapeutic results. The benefits of targeted therapy and biomarker research go beyond their immediate clinical impact to encompass the whole cancer landscape. Comprehending the genetic underpinnings of thyroid cancer facilitates the creation of novel treatments that specifically target aberrant molecules. This advances the treatment of thyroid cancer and advances precision medicine, paving the way for the treatment of other cancers. Taken simply, more study on thyroid cancer is promising for better patient care. The concepts discovered during this investigation have the potential to completely transform the way that care is provided, bringing in a new era of personalized, precision medicine. This paradigm shift could improve the prognosis and quality of life for individuals with thyroid cancer and act as an inspiration for advances in other cancer types.