TERT Promoter Mutations Research Articles

Effect of the TERT mutation on the prognosis of patients with urothelial carcinoma: a systematic review and meta-analysis

BackgroundTelomerase reverse transcriptase (TERT) mutation represents the most prevalent genetic mutation found in urothelial carcinoma (UC) and holds potential as a prognostic indicator for tumor outcomes. However, the association between TERT mutation and prognosis in UC patients remains poorly elucidated due to conflicting findings in existing literature. Therefore, this study aimed to investigate the effect of the TERT mutation on the survival of UC patients.MethodsWe systematically searched the PubMed, Embase, and Cochrane Library databases for studies that investigated the relationship between the TERT mutation and the prognosis of UC patients. Endpoints included the 2-year and 5-year recurrence-free survival (RFS) and overall survival (OS). The Newcastle–Ottawa Scale (NOS) tool was used to assess the risk of bias in the included studies. Review Manager 5.3 was used for the meta-analysis.ResultsNine studies with a total of 1,552 patients were included in the analysis. Two studies were prospective, and seven were retrospective. The TERT promoter mutation was associated with a lower 2-year OS (relative risk [RR] = 0.92, 95% confidence interval [CI] 0.86–0.98; P = 0.007) and a lower 5-year OS (RR = 0.80, 95% CI 0.68–0.94; P = 0.008) compared with the TERT wild type. However, no significantly differences were found between two groups in terms of HR for OS (hazard ratio [HR] = 1.29, 95% CI 0.80–2.08; P = 0.29). Furthermore, we investigated the differences in RFS and disease-specific survival (DSS) between the two groups.ConclusionThe TERT mutation increases the risk of death and decreases the survival time of UC patients. TERT may be a valuable marker with individual prognostic value.

Risk-stratified Distant Metastatic Thyroid Cancer with Clinicopathological Factors and BRAF/TERT Promoter Mutations.

To assess the prognostic value of clinicopathological factors as well as BRAF and TERT promoter mutations in predicting distant metastasis in patients with papillary thyroid cancer. The status of BRAF and TERTp mutations were available in 1,208 thyroid cancer patients who received thyroidectomy at Jiangyuan Hospital Affiliated to Jiangsu Institute of Nuclear Medicine from January 2008 to December 2021. Based on inclusion criteria, 99 distant metastasis thyroid cancers (DM-TCs) and 1055 patients without DM (Non-DM-TCs) were retrospectively reviewed. After univariate and multivariate analyses, a risk model was established for DM prediction based on factors: T3/T4 stage, lymph node metastasis (LNM) number over 5, and BRAF/TERT mutations (TLBT). It was defined based on the number of TLBT factors: low risk (no risk factor, n=896), intermediate risk (1 risk factor, n=199), and high risk (≥2 risk factors, n=59). Notably, compared with patients with low and intermediate risks, patients assigned to high TLBT risk have a shorter time of DM disease-free survival. Except for gene mutation, other factors were also included in the 2015 American Thyroid Association (ATA) risk guideline. Comparing with the ATA risk category, this risk model showed a better performance in predicting DM-TCs. This study proposes a TLBT risk classifier consisting of T3/T4 stages, LNM (n>5), and BRAF+TERTp mutations for predicting DM-TCs. TLBT risk stratification may help clinicians make personalized treatment management and follow-up strategies.

Pathogenic alterations in PIK3CA and KMT2C are frequent and independent prognostic factors in anal squamous cell carcinoma treated with salvage abdominoperineal resection.

The management of anal squamous cell carcinoma (ASCC) has yet to experience the transformative impact of precision medicine. Conducting genomic analyses may uncover novel prognostic biomarkers and offer potential directions for the development of targeted therapies. To that end, we assessed the prognostic and theragnostic implications of pathogenic variants identified in 571 cancer-related genes from surgical samples collected from a homogeneous, multicentric French cohort of 158 ASCC patients who underwent abdominoperineal resection treatment. Alterations in PI3K/AKT/mTOR, chromatin remodeling, and Notch pathways were frequent in HPV-positive tumors, while HPV-negative tumors often harbored variants in cell cycle regulation and genome integrity maintenance genes (e.g., frequent TP53 and TERT promoter mutations). In patients with HPV-positive tumors, KMT2C and PIK3CA exon 9/20 pathogenic variants were associated with worse overall survival in multivariate analysis (Hazard ratio (HR)KMT2C = 2.54, 95%CI = [1.25,5.17], P value = .010; HRPIK3CA = 2.43, 95%CI = [1.3,4.56], P value = .006). Alterations with theragnostic value in another cancer type was detected in 43% of patients. These results suggest that PIK3CA and KMT2C pathogenic variants are independent prognostic factors in patients with ASCC with HPV-positive tumors treated by abdominoperineal resection. And, importantly, the high prevalence of alterations bearing potential theragnostic value strongly supports the use of genomic profiling to allow patient enrollment in precision medicine clinical trials.

Comparative Analysis of the Prognostic Significance of IDH,TERT, EGFR and MGMT Status in Patients with Adult Non-H3-Altered Grade 4 Gliomas: A Prospective Cohort Study

IntroductionGliomas continue to have a dismal prognosis. A myriad of genetic alterations has been described in this subset of tumors over the last decades. The integrative interpretation of the biomarker constellation for individual patients remains unclear. This study aims to evaluate the impact of some known genetic factors as prognostic biomarkers in grade 4 gliomas. MethodsAdult non-H3-altered grade 4 gliomas who underwent maximal safe resection accompanied by adjuvant therapy were successively enrolled since January 2019 till January 2021. Patient data were documented preoperatively and during the follow-up visits. The genetic profiling of the tumors included IDH-1 and IDH-2 mutation, MGMT promoter methylation rate, EGFR gene amplification and TERT promoter (TERTp) mutation. ResultsMean Overall survival (OS) and Progression-free survival (PFS) were 14.45±5.13 months (3-24 months) and 10.66±4.87 months respectively. TERTp-mutant group had a significantly lower OS (10.9 vs 15.9) and PFS (6.9 vs 12.3) than TERTp wildtype group. In the TERT-mutant group, those with concomitant IDH wildtype tumor had higher OS and PFS, comparable to those with both TERTp and IDH wildtype tumors. In multivariate analysis, IDH mutation and TERTp wildtype status were predictive of longer OS and PFS. While IDH and absence of TERTp mutation were associated with KPS>80 across the follow-ups, their predictive values were inferior to preoperative KPS scores. ConclusionTERTp mutation and IDH-wildtype status were associated with worse OS and PFS and lower follow-up KPS score in surgically resected gliomas, while MGMT and EGFR status did not have considerable prognostic value in this study.

Differential diagnosis of small hepatocellular nodules incirrhosis: surrogate histological criteria of TERT promotermutations.

The differential diagnosis of small hepatocellular nodules in cirrhosis between dysplastic nodules and hepatocellular carcinoma (HCC) remains challenging on biopsy. As TERT promoter (pTERT) mutations may indicate the nodules already engaged in the malignant process, the aim of this study was to identify histological criteria associated with pTERT mutations by detecting these mutations by ddPCR in small formalin-fixed paraffin-embedded (FFPE) hepatocellular nodules arising in cirrhosis. We built a bicentric cohort data set of 339 hepatocellular nodules < 2 cm from cirrhotic samples, divided into a test cohort of 299 resected samples and a validation cohort of 40 biopsies. Pathological review, based on the evaluation of 14 histological criteria, classified all nodules. pTERT mutations were identified by ddPCR in FFPE samples. Among the 339 nodules, ddPCR revealed pTERT mutations in 105 cases (31%), including 90 and 15 cases in the test and validation cohorts, respectively. On multivariate analysis, three histological criteria were associated with pTERT mutations in the test cohort: increased cell density (P = 0.003), stromal invasion (P = 0.036) and plate-thickening anomalies (P < 0.001). With the combination of at least two of these major criteria, the AUC for predicting pTERT mutations was 0.84 in the test cohort (sensitivity: 86%, specificity: 83%) and 0.81 in the validation cohort (sensitivity: 87%, specificity: 76%). We identified three histological criteria as surrogate markers of pTERT mutations that may be used in routine biopsy to more clearly classify small hepatocellular nodules arising in cirrhosis.

Molecular Markers Are Associated with Onset of Radioiodine Refractoriness in Patients with Papillary Thyroid Carcinoma.

The onset of radioiodine-refractory thyroid carcinoma (RR-TC) is a negative predictor of survival and has been linked to the presence of BRAFV600E mutations in papillary thyroid cancer. We aimed to identify further genetic alterations associated with RR-TC. Methods: We included 38 patients with papillary thyroid cancer who underwent radioiodine imaging and 18F-FDG PET/CT after total thyroidectomy. The molecular profile was assessed by next-generation sequencing. The time to the onset of RR-TC for different genetic alterations was compared using the log-rank test. Results: The median onset to RR-TC was 0.7 and 19.8 mo in patients with and without, respectively, telomerase reverse transcriptase promoter mutations (P = 0.02) and 1.7 and 19.8 mo in patients with and without, respectively, a tumor protein 53 mutation (P < 0.01). This association was not observed for BRAFV600E mutations (P = 0.49). Conclusion: Our data show a significant association between the onset of RR-TC and mutations in telomerase reverse transcriptase promoter and tumor protein 53, indicating the need for a more extensive diagnostic workup in these patients. Certain genetic changes put patients with thyroid cancer at risk of developing cancer spread that does not respond to radioiodine therapy.

TERT promoter mutations and gene amplification in endometrial cancer

ObjectiveTo assess the clinicopathologic, molecular profiles, and survival outcomes of patients with endometrial carcinomas (ECs) harboring telomerase reverse transcriptase (TERT) hotspot mutations or gene amplification. MethodsECs harboring somatic TERT promoter hotspot mutations or gene amplification (TERT-altered) were identified from 1944 ECs that underwent clinical tumor-normal sequencing from 08/2016–12/2021. Clinicopathologic variables, somatic mutation profiles, and survival outcomes of TERT-alt and TERT-wild-type EC were assessed. ResultsWe identified 66 TERT-altered ECs (43 TERT-mutated and 23 TERT-amplified), representing 3% of the unselected ECs across histologic subtypes. Most TERT-altered ECs were of copy number (CN)-high/TP53abn molecular subtype (n = 40, 60%), followed by microsatellite-unstable (MSI-H) or CN-low/no specific molecular profile (NSMP)(n = 13, 20% each). TERT-amplified and TERT-mutated ECs were molecularly distinct, with TERT-amplified ECs being more genomically instable and more frequently harboring TP53 and PPP2R1A alterations (q < 0.1). Compared to TERT-wild-type ECs, TERT-altered ECs were more commonly of CN-H/TP53abn molecular subtype (31% vs 57%, p = 0.001), serous histology (10% vs 26%, p = 0.004), and were significantly enriched for TP53, CDKN2A/B, and DROSHA somatic genetic alterations (q < 0.1). Median progression-free survival was 18.7 months (95% CI 11.8–not estimable [NE]) for patients with TERT-altered EC and 80.9 months (65.8-NE) for patients with TERT-wild-type EC (HR 0.33, 95% CI 0.21–0.51, p < 0.001). Similarly, median overall survival was 46.7 months (95% CI 30-NE) for TERT-altered EC patients and not reached for TERT-wild-type EC patients (HR 0.24, 95% CI 0.13–0.44, p < 0.001). ConclusionTERT-altered ECs, although rare, are enriched for CN-high/TP53abn tumors, TP53, CDKN2A/B and DROSHA somatic mutations, and independently predict worse survival outcomes.

Dysregulated microRNA Expression Relevant to TERT Promoter Mutations in Tonsil Cancer-A Pilot Study.

Tonsillar squamous cell carcinomas (TSCCs) exhibit high rates of human papillomavirus (HPV) positivity. The expression profiles of microRNA (miRNA), which are small RNA molecules that play pivotal roles in biological processes, in TSCC in relation to the HPV status and cancer-related genetic mutations are not well investigated. Herein, we expanded our previous research, which was focused on established clinicopathological and genetic mutational data, to profile miRNA expression in TSCC, aiming to identify clinically relevant targets for early diagnosis and therapeutic intervention. The miRNA profiles were analyzed using the nCounter Nanostring miRNA Expression assay in 22 surgically resected TSCC tissues and their contralateral normal tonsil tissues. The TERT promoter (TERTp) gene was the only relevant candidate gene associated with differentially expressed miRNAs in TSCC. Hierarchical clustering analysis revealed high expression levels of hsa-miR-1285-5p, hsa-miR-1203, hsa-miR-663a, hsa-miR-1303, hsa-miR-33a-5p, and hsa-miR-3615 coupled with low expression levels of hsa-miR-3182, hsa-miR-219a-2-3p, and hsa-miR-767-3p, which were associated with HPV-positive TSCC (p = 0.009). Functional enrichment analysis revealed that these dysregulated miRNAs tended to be involved in protein binding (molecular function) and cellular components (biological processes). Therefore, hsa-miR-1285-5p and hsa-miR-663a may be associated with HPV-positive TERTp-mutated tumors and may serve as potential treatment targets and biomarkers for early detection.

TERT promoter mutation positive oral cavity carcinomas, a clinically and genetically distinct subgroup of head and neck squamous cell carcinomas.

The importance of TERT promoter (pTERT) mutation of oral cavity squamous cell carcinoma (OCSCC) with clinical features and genetic alterations are not well recognized. We retrospectively analyzed genetic data from multiple databases, including 260 cases from the C-CAT database, 407 cases from the MSK-MetTropism database, and 40 OCSCC datasets from in-house clinical samples. From C-CAT database, TP53 (66%), CDKN2A (51%), and pTERT (29%) were the most frequent mutations observed. pTERT mutations were more prevalent in OCSCC (63%), younger individuals, and women (46%), with lower rates of alcohol abuse and smoking and co-mutated with TP53, HRAS, and CASP8. MSK-MetTroposim data validated with the enrichment of pTERT mutations in OCSCC, among women and Asian individuals. In-house datasets OCSCC with pTERT mutation (50%) characterized by fewer recurrent neck metastases. The study suggests that OCSCC with pTERT mutation represents a distinct subgroup with unique clinical and genetic characteristics.

Neuroepithelial tumor with EWSR1::PATZ1 fusion: A literature review.

We present the clinicopathological and molecular genetic characteristics of a neuroepithelial tumor (NET), EWSR1::PATZ1 fusion-positive with a literature review. This fusion has recently been discovered in rare central nervous system tumors and soft tissue sarcomas and was not included in the fifth edition of the WHO classifications. We identified this fusion in 2 NETs. The first case involved a 7-year-old girl and the second case occurred in a 53-year-old man; both presented with headaches and vomiting. The pediatric case initially showed an intermediate grade of the tumor, but upon recurrences, it transformed into a high-grade tumor with 2 relapses in 8.3 years. This case exhibited high mitotic activity (20/10 high-power fields), and a high Ki-67 index (21%). The TERT promoter (TERTp) mutation was present in both initial and recurrent tumors. In contrast, the adult case was a low-grade tumor with no mitotic activity or recurrence over 13.5 months after subtotal resection and gamma knife surgery. Interestingly, the pediatric case demonstrated a longer survival time compared to conventional glioblastoma. The TERTp mutation, similar to being a molecular signature in adult-type glioblastoma, could also be an indicator of high-grade behavior in PATZ1 fusion NET.

Molecular Pathological Markers and TERT Promoter Mutations: Correlations with Clinicopathological Features and Distant Metastasis in Turkish Patients with Papillary Thyroid Carcinoma

Molecular Pathological Markers and TERT Promoter Mutations: Correlations with Clinicopathological Features and Distant Metastasis in Turkish Patients with Papillary Thyroid Carcinoma

THU683 TERT Promoter Mutations, But Not BRAFV600EMutation, Correlate With The American Thyroid Association And TNM Staging Systems And Predict Outcome Of Differentiated Thyroid Cancer

Abstract Disclosure: N. Mukhtar: None. K. Alhamoudi: None. M. Alswailem: None. H. Al-Hindi: None. A.K. Murugan: None. B. Alghamdi: None. A.S. Alzahrani: None. Context: The American Thyroid Association risk stratification (ATA) and the American Joint Committee on Cancer Tumor Node Metastases (TNM) predict recurrence and mortality of differentiated thyroid cancer (DTC). BRAFV600E and TERT promoter mutations have been shown to predict DTC outcome. Our objectives were to study these molecular markers in terms of their interaction and potential incremental prognostic values over the ATA and TNM staging systems. Patients and Methods: We studied 315 non-selected patients, 229 females, 86 males with a median age of 36 years (IQR 24-49). Data were extracted from medical records. BRAFV600E and TERT promoter mutations were tested by PCR-based Sanger sequencing. Persistent disease (PD) included all patients in structurally or biochemically incomplete and indeterminate response as defined by the 2015 ATA guidelines. Data were analysed using Chi-Square and Fisher Exact test and Kaplan Meier analysis. Results: Of 315 patients tested, 138 (43.8%) had BRAFV600E-positive tumors and 77 (24.5%) were positive for TERT promoter mutations. The BRAFV600E mutation did not correlate with the ATA and TNM staging, being non-significantly different in various stages of these systems and did not predict the development of PD (P 0.11). Unlike BRAFV600E, TERT promoter mutations were more frequent in the ATA high-risk than in intermediate- or low-risk tumors (P 0.01) and in TNM stages III and IV than in lower stages (P &amp;lt;0.001). TERT promoter mutations also predicted the outcome being present in 36.4% of patients with PD compared to only 15.6% in those without evidence of disease (P &amp;lt;0.0001). The same pattern was also seen when BRAFV600E and TERT promoter mutations were combined. TERT promoter mutations alone or TERT promoter + BRAFV600E mutations predicted the development of PD in 100% of patients in TNM stage IV or high-risk ATA stage. Conclusions:TERT promoter mutations alone or in combination with BRAFV600E mutation, but not BRAFV600E mutation alone, correlated well with the ATA and TNM staging and predicted development of PD, especially in higher stages of these systems. The combination of high-risk ATA or TNM stage IV with TERT promoter mutations is highly predictive of development of PD predicting PD in 100% of cases with these combinations. Presentation: Thursday, June 15, 2023

THU484 Distinct Genetic Characteristics In Follicular Thyroid Cancer With Different Metastatic Potentials

Abstract Disclosure: S. Kwak: None. E. Lee: None. Y. Park: None. Although most follicular thyroid cancers (FTCs) show excellent prognosis, more than 5% accompany distant metastasis, often diagnosed unexpectedly in the advanced stage. Genetic or genomic markers have been shown to be useful as a prognostic tool in many cancers, but it is unclear whether genetic markers predicting the metastatic potential of FTCs exist. To investigate, 11 pairs of matched formalin fixed paraffin embedded tissue samples of primary (PTM1) and metastatic tumors (MT) from FTC patients with distant metastasis were analyzed by whole exome sequencing. For validation, 78 unmatched FTC samples including 49 well-differentiated tumors, 15 poorly-differentiated tumors and 14 anaplastic thyroid cancer (ATC) samples were analyzed by targeted sequencing. Among the 11 paired PTM1 and MT tumors, 10 showed concordant driver mutations (NRAS, HRAS, DICER1, EIF1AX), and the TERT promoter mutation was concordantly found in 6 pairs. However, the concordance rate of other somatic mutations in paired samples were found to be only 16.2%. Other mutational characteristics such as mutational signatures and CNVs also differed, suggesting the independent subclonal evolution of the paired MT from the PTM1 after metastasis. Interestingly, the frequency of mutations including driver, TERT promoter, and other mutations was lower in primary tumors without metastases (PTM0). Mutational characteristics of PTM0 also differed from those of PTM1 and MT, suggesting that the mutational or molecular characteristics of PTs at the time of diagnosis may distinguish metastatic potential. In a pooled analysis including published data of follicular patterned tumors, we found that metastatic or aggressive tumors were more likely to have the RAS mutation, which tended to be coupled with TERT, DICER1, EIF1AX, and TP53, gradually from minimally invasive FTC, widely invasive FTC to poorly differentiated thyroid cancer (PDTC) and ATC. Transcriptomic profiles from The Cancer Genome Atlas (TCGA) and our data (SNUH) showed RAS(+)/TERT(+) mutated tumors and RAS(+)/TERT(-) tumors had differences in several intracellular signal pathways. Therefore, when follicular neoplasm is diagnosed, NRAS and HRAS mutation tests followed by TERT promoter mutation tests may help diagnose FTCs with metastatic potential. Other genetic mutations could be candidates for a diagnostic or prognostic marker, and large-scale validation studies are warranted.This study was funded by the Basic Science Research Program through the National Research Foundation of Korea, funded by the Ministry of Science, ICT &amp; Future Planning (NRF-2019R1A2C2084332). Presentation: Thursday, June 15, 2023

SAT576 Change Is Not Always For The Best! A Transformation of Papillary Into Metastatic Anaplastic Thyroid Carcinoma

Abstract Disclosure: J. Syeda: None. R. Zafar: None. K. Rajamani: None. INTRODUCTION: Anaplastic thyroid carcinoma (ATC) can occur de-novo or from preexisting well-differentiated thyroid carcinoma (1). The presence or absence of certain driver mutations can help predict the likelihood of this transformation process. We present a case of an elderly female with an initial diagnosis of well-differentiated papillary thyroid cancer (PTC) with a transformation into metastatic anaplastic thyroid carcinoma (ATC). CASE PRESENTATION: An 81-year-old female patient was initially seen 8 years ago with a 35-year history of goiter. At the initial presentation, she felt well and did not have any symptoms. Physical examination revealed an enlarged thyroid gland with left lobe nodularity. A thyroid ultrasound showed a multinodular thyroid gland including a 2x1.7x1.2 cm solid nodule with macro calcifications in the right lobe, 2.8x2.6x2.5 cm solid nodule, and 1.6x1.3x1.6 cm heterogeneous solid nodule with calcifications and irregular margins in the left lobe. She had a fine needle aspiration of these three nodules. The right nodule was non-diagnostic and both left nodules were positive for PTC. She underwent a total thyroidectomy and central lymph node dissection. Radioactive iodine treatment with 163mCi was administered after surgery. One and a half years after surgery, her thyroglobulin levels started trending upward. This led to a further workup including a PET/CT scan, which showed a hyper metabolic 6 mm left supraclavicular lymph node. Needle biopsy of this lymph node disclosed metastatic PTC. The pathologic diagnosis following surgical resection was positive for metastatic poorly differentiated thyroid carcinoma. A subsequent PET/CT scan and a thyroid ultrasound showed an abnormal uptake of the left neck lymph node and additional metastatic nodes in the left neck respectively. A core needle biopsy of these lesions was positive for ATC. Foundation One CDx testing was positive for BRAF V600E, TP53, and TERT promoter mutations. Cellblock from the initial thyroidectomy was reevaluated by pathology and confirmed no evidence of ATC. Foundation One CDx testing of the thyroidectomy specimen was positive for BRAF V600E and TERT promoter mutations. Surveillance imaging shows mediastinal adenopathy, left pleural thickening, and bone and liver metastases. DISCUSSION: Anaplastic transformation is not uncommon (1). This case supports the evidence that TERT promoter mutations may not trigger anaplastic transformation but may predispose to the aggressive PTC phenotype prone to conversion to ATC when one of the ATC-related “second hit” genetic events occurs (2). This case suggests that the “second hit” event is a TP53 mutation. The detection of a TP53 mutation in PTC with an aggressive phenotype may help predict anaplastic transformation. REFERENCES: 1-Endocrine Pathology. 2021 Mar; 32(3):347-356. 2- Semin Cancer Biol. 2020 Apr; 61: 23-29. Presentation: Saturday, June 17, 2023

THU510 The Frequency Of Mutations In Advanced Thyroid Cancer In Japan: A Real Clinical Setting

Abstract Disclosure: S. Toda: None. A. Takahashi: None. K. Masudo: None. H. Iwasaki: None. Background: Thyroid cancer has a high incidence of actionable genetic alterations, but the frequency of mutations in advanced thyroid cancer that requires drug therapy is unknown. Therefore, we examined the outcomes of genetic testing performed in a real clinical setting for the purpose of pharmacotherapy. Methods: In Japan, Oncomine Dx is approved for thyroid cancer that requires drug therapy, and comprehensive genomic profiling is approved for anaplastic thyroid carcinoma and other thyroid carcinomas after the induction of tyrosine kinase inhibitors. We retrospectively reviewed the cases of those who had their tests performed between 2020 and 2022. Results: The study included 65 patients, and the testing methods used were Oncomine Dx in 36 cases, FoundationOne in 25 cases, and FoundationOne Liquid in 4 cases. With a median age of 74 years (range 17–86), 42 were female and 23 were male. Moreover, 13 cases had anaplastic thyroid carcinoma (ATC), 4 follicular thyroid carcinoma (FTC), 42 papillary thyroid carcinoma (PTC), and 6 poorly differentiated thyroid carcinoma (PDTC). Of the PTC examined by Oncomine Dx, 96.8% (30/31) were RAI-refractory; all comprehensive genomic profiling testing cases except ATC had previously been treated with tyrosine kinase inhibitors. In the following cases, actionable mutations were observed. Among 13 ATC cases, 46.2% (6) had BRAF mutation and 7.7% (1) had RET fusion. Of 42 PTC cases, 85.7% (36) had BRAF mutation and 7.1% (3) had RET fusion. Of 6 PDTC cases, 33.3% (2) had BRAF mutation and 16.7% (1) had RET fusion. No actionable mutations were observed in FTC (0/4). We found one case each of ATC and PTC with tumor mutation burden of 10 or higher, both with BRAF mutation. NTRK fusion was not observed in any of the 65 patients studied. There were four PTC cases (9.5%) with iodine accumulation in metastases, two with BRAF mutations, one with RET fusion, and one without detectable mutations. Comparing mutations in ATC and non-ATC, TERT promoter mutations were found in 84.6% of ATC (11/13) vs. 56.2% of non-ATC (9/16), whereas TP53 mutations were found in 76.9% of ATC (10/13) vs. 12.5% of non-ATC (2/16). ATC has a significantly higher prevalence of TP53 mutations. Conclusion: Advanced thyroid cancer is more likely to have actionable mutations. BRAF mutations in advanced PTC may be more common than those previously reported in standard PTC. Moreover, ATC has a higher rate of TP53 mutation than other thyroid carcinomas. Presentation: Thursday, June 15, 2023

SAT630 Analytical Validation Of A Telomerase Reverse Transcriptase (TERT) Promoter Mutation Assay

Abstract Disclosure: P. Iyer: None. R. Dadu: Advisory Board Member; Self; Exelixis, Inc., Bayer, Inc. Research Investigator; Self; Merck, Exelixis, Inc., AstraZeneca. A. Barque: Employee; Self; Veracyte, Inc. Stock Owner; Self; Veracyte, Inc. Z. Cleslei: Employee; Self; Veracyte, Inc. Stock Owner; Self; Veracyte, Inc. H. Jiang: Employee; Self; Veracyte, Inc. Stock Owner; Self; Veracyte, Inc. S. Walsh: Employee; Self; Veracyte, Inc. Stock Owner; Self; Veracyte, Inc. X. Zheng: Employee; Self; Veracyte, Inc. Stock Owner; Self; Veracyte, Inc. Y. Hao: Employee; Self; Veracyte, Inc. Stock Owner; Self; Veracyte, Inc. J. Huang: Employee; Self; Veracyte, Inc. Stock Owner; Self; Veracyte, Inc. J.P. Klopper: Employee; Self; Veracyte, Inc. Stock Owner; Self; Veracyte, Inc. R.T. Kloos: Employee; Self; Veracyte, Inc. Stock Owner; Self; Veracyte, Inc. M. Cabanillas: Advisory Board Member; Self; Exelixis, Inc., Bayer, Inc. Consulting Fee; Self; Lilly USA, LLC, Bayer, Inc. Research Investigator; Self; Genentech, Inc., Merck. TERT promoter mutations are relatively enriched in larger, aggressive thyroid cancers and these malignancies carry an independently decreased rate of disease free and disease specific survival when compared to thyroid cancers with wild type TERT promoter gene sequences. High quality analytical validation of a diagnostic test promotes confidence in the results which inform clinical decision making. TERT promoter mutation testing is now offered as a complement to Afirma Genomic Sequencing Classifier (GSC) testing in thyroid nodules that are not designated as molecularly benign. The Afirma TERT test was developed at Veracyte, Inc. based on the AmpliSeq-for-Illumina technology to detect TERT promoter variants C228T and C250T in genomic DNA (gDNA) extracted from patient thyroid fine needle aspirates (FNAs) sent for Afirma GSC testing, without any need for increased needle passes or sample volume. Herein, we describe the analytical performance of the Afirma TERT test. We examined the analytical sensitivity of the Afirma TERT test to varied input DNA amounts and the limit of detection (LOD) of variant allele frequency (VAF). We determined the negative percent agreement (NPA) and the positive percent agreement (PPA) of the Afirma TERT test against a reference primer pair. We also evaluated the analytical specificity from potential interfering substances such as RNA and blood gDNA. Further, the intra-run, inter-run and inter-laboratory reproducibility of the assay were examined. Analytical sensitivity analysis showed that the Afirma TERT test is tolerant to variation in DNA input amount (7-13 ng) and can detect expected positive TERT promoter variants down to 5% VAF LOD at 7ng DNA input with &amp;gt; 95% sensitivity. Both NPA and PPA were 100% against the reference primer pair. Analytical specificity studies demonstrated that the Afirma TERT test remains accurate in presence of 20% RNA or 80% blood gDNA for an average patient sample that typically has 30% VAF. The Afirma TERT test results are highly reproducible across different operators, runs, reagent lots, and laboratories. The Afirma TERT test also demonstrated a 100% confirmation rate when compared with an external NGS-based reference assay executed in a non-Veracyte laboratory. The analytical robustness and reproducibility of the Afirma TERT test support its routine clinical use among thyroid nodules with indeterminate cytology that are Afirma GSC suspicious or Bethesda V/VI nodules. Presentation: Saturday, June 17, 2023

How do BRAFV600E and TERT promoter mutations interact with the ATA and TNM staging systems in thyroid cancer?

The American Thyroid Association risk stratification (ATA) and the American Joint Committee on Cancer Tumor Node Metastases (TNM) predict recurrence and mortality of differentiated thyroid cancer (DTC). BRAFV600E and TERT promoter mutations have been shown to correlate with the histopathological features and outcome of DTC. Our objectives were to study the correlation of these molecular markers with these clinicopathological-staging systems. We studied 296 unselected patients, 214 females and 82 males with a median age of 36 years (IQR 23.3-49.0). BRAFV600E and TERT promoter mutations were tested by PCR-based Sanger sequencing. Data were extracted from medical records and analysed using Chi-Square and Fisher Exact tests and Kaplan Meier analysis. Of 296 patients tested, 137 (46.3%) had BRAFV600E-positive tumors and 72 (24.3%) were positive for TERT promoter mutations. The BRAFV600E mutation did not correlate with the ATA and TNM staging, being non-significantly different in various stages of these systems and did not predict the development of persistent disease (PD) (P 0.12). Unlike BRAFV600E, TERT promoter mutations were more frequent in the ATA high-risk than in intermediate- or low-risk tumors (P 0.006) and in TNM stages III and IV than lower stages (P <0.0001). TERT promoter mutations also predicted the outcome, being present in 37.2% of patients with PD compared to only 15.4% in those without evidence of disease (P <0.0001). The same pattern was also seen when BRAFV600E and TERT promoter mutations were combined. TERT promoter mutations alone or in combination with BRAFV600E mutation, but not BRAFV600E mutation alone, correlated well with the ATA and TNM staging and predicted development of PD, especially in higher stages of these systems.

Glomangiosarcoma-like Anaplastic Transformation in Papillary Thyroid Carcinoma: A Novel Form of Heterologous Differentiation and a Systematic Review of Heterologous Element Prevalence.

Anaplastic thyroid carcinoma (ATC) demonstrates a wide variety of morphologies and is characteristically associated with a differentiated thyroid carcinoma component. Heterologous differentiation is a rare, potentially challenging phenomenon in ATC, mostly observed as osteosarcomatous or chondrosarcomatous differentiation. We now describe a novel 'glomangiosarcoma-like' differentiation, review our archival experience from two institutions (UPMC, CC), and perform a systematic review for the prevalence of heterologous elements in ATC. The patient is a 57-year-old female who presented with 4.5cm left thyroid, and 3.4cm neck masses. Histologically, the thyroid demonstrated a differentiated high grade papillary thyroid carcinoma, tall cell and hobnail/micropapillary subtypes transitioning into an anaplastic component with spindled to ovoid cells with hemangiopericytoma-like vasculature showing CD34 positivity, variable muscle marker expression and pericellular lace-like type IV collagen deposition. The neck mass consisted solely of the latter morphology. Targeted next-generation sequencing was performed on high grade DTC and adjacent ATC from the thyroid as well as ATC from the neck metastasis. All three components shared BRAFV600E, TERT promoter, and PIK3CA mutations confirming a clonal origin. Archival (UPMC: n = 150, CC: n = 74) and literature review showed no prior examples. Systematic review and meta-analysis of prevalence showed a baseline pooled prevalence (generalized linear mixed model) of heterologous elements of any type to be 1.6% (95% confidence interval: 1.0-2.6%) for studies where this was specifically addressed. ATC with glomangiosarcoma-like heterologous differentiation is a rarity among an already rare morphologic category with unique diagnostic pitfalls.

Subcentimetric papillary thyroid carcinoma with extensive lymph node and brain metastasis: case report and review of literature.

We report a 61-year-old male patient without personal history of thyroid carcinoma or radiation exposure. In 2011, he presented with a cervical mass whose biopsy diagnosed a papillary thyroid carcinoma (PTC) in a lymph node metastasis (LNM). Total thyroidectomy with lymphadenectomy of central and ipsilateral compartment was performed. Histopathology identified a 2 mm follicular variant of PTC and LNM in 25/25 lymph nodes. The patient was treated with 150 mCi of radioactive iodine (RAI), followed by levothyroxine suppressive therapy. In 2016, a retrotracheal mass was diagnosed, suggesting local recurrence; patient was submitted to surgical excision and RAI therapy (120 mCi). Due to seizures, in 2019, a brain CT was performed that diagnosed brain metastases. The patient underwent debulking of the main lesion. Histopathology analysis confirmed a metastatic lesion with variated morphology: classical PTC and follicular pattern and hobnail and tall cell features. Molecular analysis revealed BRAFV600E in LNM at presentation and BRAFV600E and TERT promoter (TERTp) mutations in the recurrent LNM and brain metastasis. Based upon this experience we review the reported cases of subcentimetric PTC with brain metastases and discuss the molecular progression of the present case. Papillary microcarcinoma (PMCs) usually have very good prognosis with low impact on patient survival. PMCs presenting in elderly patients with LNM at diagnosis may carry a guarded outcome. Brain metastasis although rare indicate aggressive phenotypic features. Patient risk stratification of PMCs based on histopathological analysis and genetic testing may have a significant impact on prognosis providing therapeutic markers, that may predict disease progression and overall outcome.

Multi-parameter MRI based radiomics nomogram for predicting telomerase reverse transcriptase promoter mutation and prognosis in glioblastoma.

To investigate the clinical utility of multi-parameter MRI-based radiomics nomogram for predicting telomerase reverse transcriptase (TERT) promoter mutation status and prognosis in adult glioblastoma (GBM). We retrospectively analyzed MRI and pathological data of 152 GBM patients. A total of 2,832 radiomics features were extracted and filtered from preoperative MRI images. A radiomics nomogram was created on the basis of radiomics signature (rad-score) and clinical traits. The performance of the nomogram in TERT mutation identification was assessed using receiver operating characteristic (ROC) curve, calibration curves, and clinical decision curves. Pathologically confirmed TERT mutations and risk score-based TERT mutations were employed to assess patient prognosis, respectively. The random forest (RF) algorithm outperformed the other two algorithms, yielding the best diagnostic efficacy in differentiating TERT mutations, with area under the curve (AUC) values of 0.892 (95% CI: 0.828-0.956) and 0.824 (95% CI: 0.677-0.971) in the training set and validation sets, respectively. Furthermore, the predictive power of the radiomics nomogram constructed with the rad-score and clinical variables reached 0.916 (95%CI: 0.864, 0.968) in the training set and 0.880 (95%CI: 0.743, 1) in the validation set. Calibration curve and decision curve analysis findings further uphold the clinical application value of the radiomics nomogram. The overall survival of the high-risk subgroup was significantly shorter than that of the low-risk subgroup, which was consistent with the results of the pathologically confirmed TERT mutation group. The radiomics nomogram could non-invasively provide promising insights for predicting TERT mutations and prognosis in GBM patients with excellent identification and calibration abilities.