The age- and shorter telomere-dependent TERT promoter mutation in follicular thyroid cell-derived carcinomas

TERT Promoter Mutations in Thyroid Cancer

Two mutations (C228T and C250T) in the promoter region of the telomerase reverse transcriptase (TERT) have recently been described in different types of cancer including follicular cell-derived thyroid cancer (TC). In this paper, we reviewed the rates of these mutations in different types and subtypes of TC, their association with a number of clinical and histopathological features and outcome of TC, and their potential diagnostic and prognostic roles in TC. The overall rate of these mutations in TC is about 14 % with least prevalence in the well-differentiated subtypes of papillary thyroid cancer (10-13 %). Their rates increase significantly with increasing aggressiveness of TC reaching about 40 % in the undifferentiated and anaplastic thyroid cancers. There is also clear association with increasing age of patients at the time of diagnosis of TC. The evidence is compelling but with some conflicting results for associations between TERT promoter mutations and tumor size, extrathyroidal invasion, distant metastases, high tumor TNM stage, BRAF (V600E) mutation, recurrence, and mortality. A couple of studies reported a potential diagnostic role for TERT promoter mutations in thyroid nodules with indeterminate cytology of fine needle aspiration biopsy. These studies showed 100 % specificity but very low sensitivity of 7-10 %. The sensitivity increases significantly when TERT promoter mutation testing is combined with other gene mutations, particularly BRAF (V600E) and RAS mutations. Although TERT promoter mutations seem to play significant roles in the pathogenesis of TC, the mechanisms by which they contribute to carcinogenesis remain elusive and future work is needed to fully assess the roles, interactions, and impact of these mutations on the pathogenesis, diagnosis, prognosis, and therapeutics of TC.

Genomic and transcriptomic hallmarks of poorly differentiated and anaplastic thyroid cancers

BACKGROUND

Poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) are rare and frequently lethal tumors that so far have not been subjected to comprehensive genetic characterization.

METHODS

We performed next-generation sequencing of 341 cancer genes from 117 patient-derived PDTCs and ATCs and analyzed the transcriptome of a representative subset of 37 tumors. Results were analyzed in the context of The Cancer Genome Atlas study (TCGA study) of papillary thyroid cancers (PTC).

RESULTS

Compared to PDTCs, ATCs had a greater mutation burden, including a higher frequency of mutations in TP53, TERT promoter, PI3K/AKT/mTOR pathway effectors, SWI/SNF subunits, and histone methyltransferases. BRAF and RAS were the predominant drivers and dictated distinct tropism for nodal versus distant metastases in PDTC. RAS and BRAF sharply distinguished between PDTCs defined by the Turin (PDTC-Turin) versus MSKCC (PDTC-MSK) criteria, respectively. Mutations of EIF1AX, a component of the translational preinitiation complex, were markedly enriched in PDTCs and ATCs and had a striking pattern of co-occurrence with RAS mutations. While TERT promoter mutations were rare and subclonal in PTCs, they were clonal and highly prevalent in advanced cancers. Application of the TCGA-derived BRAF-RAS score (a measure of MAPK transcriptional output) revealed a preserved relationship with BRAF/RAS mutation in PDTCs, whereas ATCs were BRAF-like irrespective of driver mutation.

CONCLUSIONS

These data support a model of tumorigenesis whereby PDTCs and ATCs arise from well-differentiated tumors through the accumulation of key additional genetic abnormalities, many of which have prognostic and possible therapeutic relevance. The widespread genomic disruptions in ATC compared with PDTC underscore their greater virulence and higher mortality.

FUNDING

This work was supported in part by NIH grants CA50706, CA72597, P50-CA72012, P30-CA008748, and 5T32-CA160001; the Lefkovsky Family Foundation; the Society of Memorial Sloan Kettering; the Byrne fund; and Cycle for Survival.

Clinical utility of TERT promoter mutations and ALK rearrangement in thyroid cancer patients with a high prevalence of the BRAF V600E mutation

Background

Mutations in the TERT promoter, ALK rearrangement, and the BRAF V600E mutation are associated with aggressive clinicopathologic features in thyroid cancers. However, little is known about the impact of TERT promoter mutations and ALK rearrangement in thyroid cancer patients with a high prevalence of BRAF mutations.

Methods

We performed Sanger sequencing to detect BRAF V600E and TERT promoter mutations and both immunohistochemistry and fluorescence in situ hybridization to identify ALK rearrangement on 243 thyroid cancers.

Results

TERT promoter mutations were not present in 192 well-differentiated thyroid carcinomas (WDTC) without distant metastasis or in 9 medullary carcinomas. However, the mutations did occur in 40 % (12/30) of WDTC with distant metastasis, 29 % (2/7) of poorly differentiated carcinomas and 60 % (3/5) of anaplastic carcinomas. ALK rearrangement was not present in all thyroid cancers. The BRAF V600E mutation was more frequently found in WDTC without distant metastasis than in WDTC with distant metastasis (p = 0.007). In the cohort of WDTC with distant metastasis, patients with wild-type BRAF and TERT promoter had a significantly higher response rate after radioiodine therapy (p = 0.024), whereas the BRAF V600E mutation was significantly correlated with progressive disease (p = 0.025).

Conclusions

The TERT promoter mutation is an independent predictor for distant metastasis of WDTC, but ALK testing is not useful for clinical decision-making in Korean patients with a high prevalence of the BRAF V600E mutation. Radioiodine therapy for distant metastasis of WDTC is most effective in patients without BRAF V600E and TERT promoter mutations.

Clinical Characteristics and Prognostic Significance of TERT Promoter Mutations in Cancer: A Cohort Study and a Meta-Analysis

BACKGROUND

The prevalence of telomerase reverse transcriptase (TERT) promoter mutations (pTERTm) in non-small-cell lung cancer (NSCLC) have been investigated, but the results were inconsistent. In addition, several studies have analysed the role of pTERTm in the etiology of various types of cancers, however, the results also remain inconsistent.

METHODS

The genomic DNA sequence of 103 NSCLC samples were analysed to investigate the frequency of pTERTm in these patients and to establish whether these mutations are associated with their clinical data. Furthermore, a meta-analysis based on previously published articles and our cohort study was performed to investigate the association of pTERTm with patient gender, age at diagnosis, metastasis status, tumour stage and cancer prognosis (5-year overall survival rate).

RESULTS

In the cohort study, 4 patients had C228T and 2 had C250T, with a total mutation frequency up to 5.8%. Significant difference of clinical data between pTERTm carriers and noncarriers was only found in age at diagnosis. In the meta-analysis, We found that pTERTm carriers in cancer patients are older than noncarriers (Mean difference (MD) = 5.24; 95% confidence interval [CI], 2.00 to 8.48), male patients were more likely to harbour pTERTm (odds Ratios (OR) = 1.38; 95% CI, 1.22 to 1.58), and that pTERTm had a significant association with distant metastasis (OR = 3.78; 95% CI, 2.45 to 5.82), a higher tumour grade in patients with glioma (WHO grade III, IV vs. I, II: OR, 2.41; 95% CI, 1.88 to 3.08) and a higher tumour stage in other types of cancer (III, IV vs. I, II: OR, 2.48; 95% CI, 1.48 to 4.15). pTERTm was also significantly associated with a greater risk of death (hazard ratio = 1.71; 95% CI, 1.41 to 2.08).

CONCLUSIONS

pTERTm are a moderately prevalent genetic event in NSCLC. The current meta-analysis indicates that pTERTm is associated with patient age, gender and distant metastasis. It may serves as an adverse prognostic factor in individuals with cancers.

TERT Promoter Mutations and Tumor Persistence/Recurrence in Papillary Thyroid Cancer

PURPOSE

A telomerase reverse transcriptase (TERT) promoter mutation was identified in thyroid cancer. This TERT promoter mutation is thought to be a prognostic molecular marker, because its association with tumor aggressiveness, persistence/recurrence, and disease-specific mortality in papillary thyroid carcinoma (PTC) has been reported. In this study, we attempted to determine whether the impact of the TERT promoter mutation on PTC persistence/recurrence is independent of clinicopathological parameters.

MATERIALS AND METHODS

Using propensity score matching, 39 patients with PTC persistence or recurrence were matched with 35 patients without persistence or recurrence, with a similar age, sex, tumor size, multifocality, bilaterality, extrathyroidal extension, and lymph node metastasis. The TERT promoter and the BRAF V600E mutations were identified from PTC samples.

RESULTS

The TERT promoter mutation was detected in 18% of PTC patients (13/74). No significant difference in the frequency of the TERT promoter mutation was observed between the persistence/recurrence group and the non-recurrence group.

CONCLUSION

These results suggest that the prognostic implications of the TERT promoter mutation are dependent on clinicopathological parameters.

Follicular cell-derived thyroid cancer

Follicular cell-derived thyroid cancers are derived from the follicular cells in the thyroid gland, which secrete the iodine-containing thyroid hormones. Follicular cell-derived thyroid cancers can be classified into papillary thyroid cancer (80-85%), follicular thyroid cancer (10-15%), poorly differentiated thyroid cancer (<2%) and undifferentiated (anaplastic) thyroid cancer (<2%), and these have an excellent prognosis with the exception of undifferentiated thyroid cancer. The advent and expansion of advanced diagnostic techniques has driven and continues to drive the epidemic of occult papillary thyroid cancer, owing to overdiagnosis of clinically irrelevant nodules. This transformation of the thyroid cancer landscape at molecular and clinical levels calls for the modification of management strategies towards personalized medicine based on individual risk assessment to deliver the most effective but least aggressive treatment. In thyroid cancer surgery, for instance, injuries to structures outside the thyroid gland, such as the recurrent laryngeal nerve in 2-5% of surgeries or the parathyroid glands in 5-10% of surgeries, negatively affect quality of life more than loss of the expendable thyroid gland. Furthermore, the risks associated with radioiodine ablation may outweigh the risks of persistent or recurrent disease and disease-specific mortality. Improvement in the health-related quality of life of survivors of follicular cell-derived thyroid cancer, which is decreased despite the generally favourable outcome, hinges on early tumour detection and minimization of treatment-related sequelae. Future opportunities include more widespread adoption of molecular and clinical risk stratification and identification of actionable targets for individualized therapies.

TERT promoter mutations in thyroid cancer: a report from a Middle Eastern population

Telomerase reverse transcriptase (TERT) promoter mutations C228T and C250T have recently been described in follicular cell-derived thyroid cancer (TC) in patients from North America and Europe. In this study, we explored whether these findings could be replicated in patients from a different ethnic group. We screened 17 benign thyroid adenomas and 265 TC samples from patients in the Middle East for these mutations by PCR and direct sequencing using DNA isolated from paraffin-embedded tumor tissues. None of the 17 benign adenomas harbored TERT promoter mutations. Of 265 TC, 34 (12.8%) harbored TERT promoter mutations, including 10/153 (6.5%) conventional papillary TC (CPTC), 8/57 (14.0%) follicular variant PTC, 9/30 (30%) tall cell variant PTC, 1/3 (30%) Hurthle cell thyroid cancer (HTC), 1/5 (20%) follicular TC, and 5/13 (38.5%) poorly differentiated TC. C250T mutation was present in only 6/265 (2.3%) cases, while C228T mutation was present in a total of 28/265 (10.6%) cases. These two mutations were mutually exclusive. TERT promoter mutations were significantly more common in older (≥45 years) than younger patients and were associated with larger tumour size, vascular invasion, higher TNM stage (stage III and IV), BRAF(V600E) mutation and persistent/recurrent disease at 6-12 months after initial treatment and at the last follow up. These associations were stronger in non-CPTC. Thus, this study on a large cohort of TC patients from Middle East demonstrates that TERT promoter mutations are relatively common, especially in the non-CPTC, and are associated with more aggressive histopathological features, BRAF(V600E) mutation, and disease persistence/recurrence than the WT TERT.

TERT promoter mutations are associated with distant metastases in upper tract urothelial carcinomas and serve as urinary biomarkers detected by a sensitive castPCR

TERT promoter C228T and C250T mutations occur in various malignancies including bladder cancer (BC) and may serve as urinary tumor markers. However, the mutation association with clinical variables in upper tract urothelial carcinomas (UTUCs) is unclear. There is also a lack of sensitive tools to detect the minor mutant TERT promoter in bulk urinary DNA. Here we analyzed 220 UTUC patients [98 with renal pelvic carcinoma (RPC) and 122 with ureter carcinoma (UC)] and developed a Competitive Allele-Specific TaqMan PCR (castPCR) for urinary assay. We identified C228T or C250T mutations in 42 of 98 (43%) RPC and 23 of 122 (19%) UC tumors. Distant metastases were significantly correlated with UTUC patients harboring TERT promoter mutations (P = 0.001). C228T were detected in 6/10 and 9/10 of urine samples from patients with mutation-carrying tumors using Sanger sequencing and castPCR, respectively. When urine samples from 70 BC patients were analyzed together, the sensitivity of urinary C228T assay was 89% and 50% for castPCR and Sanger sequencing, respectively (P < 0.001). Collectively, TERT promoter mutations occur in UTUCs with a high frequency in RPCs and predict distant metastasis. castPCR assays of the mutation are a useful tool for urine-based diagnostics of urological malignancies.

TERT promoter mutations are frequent and show association with MED12 mutations in phyllodes tumors of the breast

Background:

Phyllodes tumors are rare fibroepithelial neoplasms of the breast, which carry the potential risk of local recurrence and metastasis. Phyllodes tumors share several histological features with fibroadenomas, and no widely accepted markers for distinguishing these lesions have been identified.

Methods:

We analyzed molecular abnormalities related to telomere elongation in tumors, including TERT promoter mutations, as well as loss of expression of ATRX and DAXX, in a total of 104 phyllodes tumors and fibroadenomas.

Results:

Sequencing analyses showed that TERT promoter mutations were frequent in phyllodes tumors (30/46, 65%), but rare in fibroadenomas (4/58, 7%). Among phyllodes tumors, the mutations were more frequent in borderline tumors (13/15, 87%), but were also common in benign (9/18, 50%) and malignant tumors (8/13, 62%). Remarkably, all but one TERT promoter-mutated tumor also contained MED12 mutations, indicating that these mutations are strongly associated (P=8.4 × 10⁻⁶). Expression of ATRX and DAXX, as evaluated by immunohistochemistry, was retained in all tumors.

Conclusions:

Our observations suggest a critical role of TERT promoter mutations, in cooperation with MED12 mutations, in the development of phyllodes tumors. Because TERT promoter mutations are rare among fibroadenomas, their detection may be of potential use in discriminating between phyllodes tumors and fibroadenomas.

Mutation Profile of Well-Differentiated Thyroid Cancer in Asians

Recent advances in molecular diagnostics have led to significant insights into the genetic basis of thyroid tumorigenesis. Among the mutations commonly seen in thyroid cancers, the vast majority are associated with the mitogen-activated protein kinase pathway. B-Raf proto-oncogene (BRAF) mutations are the most common mutations observed in papillary thyroid cancers (PTCs), followed by RET/PTC rearrangements and RAS mutations, while follicular thyroid cancers are more likely to harbor RAS mutations or PAX8/peroxisome proliferator-activated receptor γ (PPARγ) rearrangements. Beyond these more common mutations, alterations in the telomerase reverse transcriptase (TERT) promoter have recently been associated with clinicopathologic features, disease prognosis, and tumorigenesis in thyroid cancer. While the mutations underlying thyroid tumorigenesis are well known, the frequency of these mutations is strongly associated with geography, with clear differences reported between Asian and Western countries. Of particular interest is the prevalence of BRAF mutations, with Korean patients exhibiting the highest rate of BRAF-associated thyroid cancers in the world. Here, we review the prevalence of each of the most common mutations in Asian and Western countries, and identify the characteristics of well-differentiated thyroid cancer in Asians.

TERT promoter mutations and gene amplification: promoting TERT expression in Merkel cell carcinoma

Telomerase activation through the induction of its catalytic component TERT is essential in carcinogenesis. The regulatory mechanism and clinical significance underlying cancer-specific TERT expression have been extensively investigated in various human malignancies, but little is known about these in Merkel cell carcinoma (MCC), an aggressive neuroendocrine skin tumor. Here we addressed these issues by determining TERT promoter mutations, gene amplification, mRNA expression and association with clinical variables in MCC. TERT mRNA was expressed in 6/6 MCC cell lines and 41 of 43 tumors derived from 35 MCC patients. Telomerase activity was detectable in all 6 cell lines and 11 tumors analyzed. TERT promoter mutations were identified in 1/6 cell lines and 4/35 (11.4%) MCC cases. The mutation exhibited UV signature and occurred in sun-exposed areas. Increased TERT gene copy numbers were observed in 1/6 cell lines and 11/14 (79%) tumors, and highly correlated with its mRNA expression (r = 0.7419, P = 0.0024). Shorter overall survival was significantly associated with higher TERT mRNA levels in MCC patients (P = 0.032). Collectively, TERT expression and telomerase activity is widespread in MCC, and may be attributable to TERT promoter mutations and gene amplification. Higher TERT expression predicts poor patient outcomes.

Mutation rate estimation for 15 autosomal STR loci in a large population from Mainland China

STR, short tandem repeats, are well known as a type of powerful genetic marker and widely used in studying human population genetics. Compared with the conventional genetic markers, the mutation rate of STR is higher. Additionally, the mutations of STR loci do not lead to genetic inconsistencies between the genotypes of parents and children; therefore, the analysis of STR mutation is more suited to assess the population mutation. In this study, we focused on 15 autosomal STR loci. DNA samples from a total of 42,416 unrelated healthy individuals (19,037 trios) from the population of Mainland China collected between Jan 2012 and May 2014 were successfully investigated. In our study, the allele frequencies, paternal mutation rates, maternal mutation rates and average mutation rates were detected. Furthermore, we also investigated the relationship between paternal ages, maternal ages, area, the time of pregnancy and average mutation rate. We found that the paternal mutation rate was higher than the maternal mutation rate and the paternal, maternal, and average mutation rates had a positive correlation with paternal age, maternal age and the time of pregnancy respectively. Additionally, the average mutation rate of coastal areas was higher than that of inland areas.

•

15 autosomal STR loci were analyzed in a large scale population in Mainland China.

•

With increases of repeat units the event of loss is more than that of gain.

•

The paternal mutation rate is higher than the maternal mutation rate.

•

There is a positive correlation between mutation rates and age and pregnancy time.

•

The average mutation rates of coastal areas are higher than that of inland areas.

TERT promoter mutations and telomere length in adult malignant gliomas and recurrences

In this report on 303 gliomas we show the highest frequency of TERT promoter mutations in gliobastomas (80%) followed by oligodendrogliomas (70%) and astrocytomas (39%). We observed positive association between TERT promoter and IDH mutations in oligodendroglial tumors (OR = 26.3; 95% CI 2.5-250.2) and inverse association in primary glioblastomas (OR = 0.13; 95% CI 0.03-0.58). Tumors with TERT promoter mutations compared to those without showed increased TERT transcription; we also showed difference in the transcription levels due to the two main mutations. Tumors with TERT promoter mutations had shorter telomeres than those without. The patients with only TERT promoter mutations showed worst survival (median survival 14.6 months) and patients with both IDH and TERT promoter mutations showed best survival (246.5 months). In patients with astrocytoma, the TERT promoter mutations only associated with poor survival (P < 0.0001); IDH mutations and 1p/19q deletions associated with increased survival (P = 0.0004). TERT promoter mutations in low grade gliomas associated with reduced progression free survival (HR 10.2; 95% CI 1.9 - 55.9). While our data affirm the role of TERT promoter mutations in glial tumors, effects on transcription and telomere length emphasise the importance of telomere biology in disease genesis and outcome.

Mutations in TERT promoter and FGFR3 and telomere length in bladder cancer

Mutations in the promoter of the telomerase reverse transcriptase (TERT) and fibroblast growth factor receptor 3 (FGFR3) genes constitute the most recurrent somatic alterations in urothelial carcinoma of bladder. In this study, we screened DNA from 327 urothelial bladder carcinomas from well-documented patients, with different stages and grades and known TERT promoter mutational status, for FGFR3 alterations and measured relative telomere length (RTL). Although, the frequency of the TERT promoter mutations was higher than those in FGFR3; however, the alterations at the two loci occurred together more frequently than per chance [Odds ratio (OR) = 4.93, 95% CI = 2.72-8.92, p < 0.0001]. While tumors with TERT promoter and FGFR3 mutations had shorter RTL than those without mutations (p < 0.0001), the TERT promoter mutations in conjunction with the common allele of the rs2853669 polymorphism defined sub-group of patients with an observed decreased overall survival (OR = 2.15, 95% CI = 1.00-4.61) and increased recurrence in patients with TaG1+TaG2 disease categories (OR = 3.68, 95%CI = 1.12-12.05). The finding of shorter telomeres in tumors with TERT promoter and/or FGFR3 mutations than without mutations implies mechanistic relevance of telomere biology in cancer progression. The observed association with recurrence and survival shows that the TERT promoter mutations can potentially be used as markers to refine selection of patients for different treatments. The overwhelming frequency of the TERT promoter mutations also represents a case for development of an eventual therapeutic target.

TERT promoter mutations are associated with distant metastases in papillary thyroid carcinoma

OBJECTIVE

Transcriptional activating mutations in the promoter of the telomerase reverse transcriptase (TERT) gene were reported at high frequency in aggressive poorly differentiated and anaplastic thyroid cancers. By contrast, the relevance of these mutations in the metastatic behavior of well-differentiated thyroid cancer is still to be defined. The aim of this work was to investigate the frequency of TERT promoter mutations in a remarkable cohort of well-differentiated papillary thyroid carcinoma that developed distant metastases (DM-PTCs) and to establish whether these mutations may be predictive of metastatic behavior.

DESIGN

We analyzed the frequency of TERT promoter mutations in a group of 43 highly aggressive DM-PTCs. As controls, we analyzed these mutations in a group of 78 PTCs without distant metastases (control-PTCs). The possible correlation between TERT promoter mutations and BRAF V600E mutation was also investigated.

METHODS

TERT promoter mutational status was evaluated by direct sequencing of the hotspot harboring the C228T and the C250T mutations.

RESULTS

In the overall cohort of 121 PTCs analyzed, 17% of cases (21/121) carried a mutation in the TERT promoter. Noticeably, 33% of DM-PTCs were mutated in the TERT promoter while only 9% of the control-PTCs showed a mutation in this locus. We also observed a positive association between BRAF V600E and TERT C228T mutations in the cohort of DM-PTCs.

CONCLUSIONS

These results indicate that TERT promoter mutations are associated with the development of distant metastases in PTCs and may help in predicting aggressive behavior in this type of tumor.

Association of TERT promoter mutation 1,295,228 C>T with BRAF V600E mutation, older patient age, and distant metastasis in anaplastic thyroid cancer

CONTEXT

The aggressive role of TERT promoter mutations has been well established in differentiated thyroid cancer but has not been established in anaplastic thyroid cancer (ATC).

RESEARCH DESIGN

We tested the mutation status by sequencing genomic tumor DNA and examined its relationship with clinicopathological characteristics of ATC.

RESULTS

Among 106 American and Chinese ATC samples, TERT 1,295,228 C>T (termed TERT C228T) mutation was found in 37 (34.9%) cases, TERT promoter mutation 1,295,250 C>T was found in four cases (3.8%), and the two mutations were mutually exclusive and collectively found in 41 cases (38.7%). TERT C228T occurred in 28 of 90 (31.1%) wild-type BRAF cases vs nine of 16 (56.3%) BRAF V600E cases, with an odds ratio of 2.85 (95% confidence interval, 0.96-8.42; P = .05). Patient age was 67.6 ± 13.6 vs 61.6 ± 11.4 years in the TERT C228T vs wild-type TERT patients (P = .02), demonstrating an association between TERT C228T and older patient age. This association was also seen within the American cohort. In this cohort, which had more available clinicopathological data, TERT C228T was associated with distant metastasis of the tumor; specifically, distant metastasis occurred in 15 of 18 (83.3%) TERT C228T patients vs eight of 26 (30.8%) wild-type TERT patients, with an odds ratio of 11.25 (95% confidence interval, 2.53-50.08; P = .001). No association was found with patient sex, tumor size, lymph node metastasis, and extrathyroidal invasion of ATC.

CONCLUSIONS

This is the largest study on the aggressive role of TERT promoter mutations in ATC, demonstrating an association of TERT C228T with BRAF V600E, older patient age, and tumor distant metastasis in ATC.

TERT promoter mutations and TERT mRNA but not FGFR3 mutations are urinary biomarkers in Han Chinese patients with urothelial bladder cancer

The TERT promoter and FGFR3 gene mutations are two of the most common genetic events in urothelial bladder cancer (UBC), and these mutation assays in patient urine have been shown to be promising biomarkers for UBC diagnosis and surveillance. These results were obtained mainly from studies of patients with UBC in Western countries, and little is known about such information in Han Chinese patients with UBC. In the present study, we addressed this issue by analyzing tumors from 182 Han Chinese patients with UBC and urine samples from 102 patients for mutations in the TERT promoter and FGFR3 and TERT mRNA expression in tumors and/or urine. TERT promoter and FGFR3 mutations were identified in 87 of 182 (47.8%) and 7 of 102 (6.7%) UBC cases, respectively. In 46 urine samples from patients with TERT promoter mutation-carrying tumors, the mutant promoter was detected in 24 (52%) prior to operation and disappeared in most examined urine samples (80%) taken 1 week after operation. TERT mRNA was detected in urine derived from 46 of 49 patients (94%) that was analyzed before operation independently of the presence of TERT promoter mutations. Collectively, FGFR3 mutations occur at a very low rate in Han Chinese UBC and cannot serve as diagnostic markers for Chinese patients. Han Chinese patients with UBC have relatively low TERT promoter mutation frequency compared with patients in Western countries, and simultaneous detection of both mutant TERT promoter and TERT mRNA improves sensitivity and specificity of urine-based diagnosis.

Telomere-regulating genes and the telomere interactome in familial cancers

Telomeres are repetitive sequence structures at the ends of linear chromosomes that consist of double-stranded DNA repeats followed by a short single-stranded DNA protrusion. Telomeres need to be replicated in each cell cycle and protected from DNA-processing enzymes, tasks that cells execute using specialized protein complexes such as telomerase (that includes TERT), which aids in telomere maintenance and replication, and the shelterin complex, which protects chromosome ends. These complexes are also able to interact with a variety of other proteins, referred to as the telomere interactome, to fulfill their biological functions and control signaling cascades originating from telomeres. Given their essential role in genomic maintenance and cell-cycle control, germline mutations in telomere-regulating proteins and their interacting partners have been found to underlie a variety of diseases and cancer-predisposition syndromes. These syndromes can be characterized by progressively shortening telomeres, in which carriers can present with organ failure due to stem cell senescence among other characteristics, or can also present with long or unprotected telomeres, providing an alternative route for cancer formation. This review summarizes the critical roles that telomere-regulating proteins play in cell-cycle control and cell fate and explores the current knowledge on different cancer-predisposing conditions that have been linked to germline defects in these proteins and their interacting partners.

Molecular alterations in endometrial and ovarian clear cell carcinomas: clinical impacts of telomerase reverse transcriptase promoter mutation

Recently, mutations of telomerase reverse transcriptase (TERT) promoter were found in several types of cancer. A few reports demonstrate TERT promoter mutations in ovarian clear cell carcinomas but endometrial clear cell carcinoma has not been studied. The aims of this study were to compare differences of molecular alterations and clinical factors, and identify their prognostic impact in endometrial and ovarian clear cell carcinomas. We evaluated mutations of the TERT promoter and PIK3CA, expression of ARID1A, and other clinicopathological factors in 56 ovarian and 14 endometrial clear cell carcinomas. We found that TERT promoter mutations were present in 21% (3/14) of endometrial clear cell carcinomas and 16% (9/56) of ovarian clear cell carcinomas. Compared with ovarian clear cell carcinomas, endometrial clear cell carcinomas showed older mean patient age (P<0.001), preserved ARID1A immunoreactivity (P=0.017) and infrequent PIK3CA mutation (P=0.025). In ovarian clear cell carcinomas, TERT promoter mutations were correlated with patient age >45 (P=0.045) and preserved ARID1A expression (P=0.003). In cases of endometrial clear cell carcinoma, TERT promoter mutations were not statistically associated with any other clinicopathological factors. In ovarian clear cell carcinoma patients with early FIGO stage (stages I and II), TERT promoter mutation was an independent prognostic factor and correlated with a shorter disease-free survival and overall survival (P=0.015 and 0.009, respectively). In recurrent ovarian clear cell carcinoma patients with early FIGO stage, TERT promoter mutations were associated with early relapse within 6 months (P=0.018). We concluded that TERT promoter mutations were present in endometrial and ovarian clear cell carcinomas. Distinct molecular alteration patterns in endometrial and ovarian clear cell carcinomas implied different processes of tumorigenesis in these morphologically similar tumors. In ovarian clear cell carcinoma of early FIGO stage, patients with TERT promoter mutation require close follow-up during the initial 6 months following chemotherapy.

TERT promoter mutations in renal cell carcinomas and upper tract urothelial carcinomas

TERT promoter mutations are identified in many malignancies including bladder cancer (BC) and upper tract urothelial carcinoma (UTUC). In contrast, no mutations were found in renal cell carcinoma (RCC) as reported in a recent study. Because the mutant TERT promoter in urine DNA was recently tested as a marker for BC, it is important to ascertain whether these mutations are truly absent in RCCs. Here we determined TERT promoter mutations in 109 patients with RCC and 14 patients with UTUC. The mutations were found in 9/96 (9.3%) clear cell RCC (ccRCC) tumors and 1/8 (13%) chromophobe RCC tumors. Among ccRCC patients, the mutation was correlated with the advanced stages and metastasis, and higher TERT expression. Among UTUCs, the mutation was detected in tumors from 3/5 (60%) patients with renal pelvic cancer and 1/9 (11%) patients with ureter cancer. The mutation was also detected in 1 of 4 urine samples from patients with mutation+ UTUC. Collectively, TERT promoter mutations do occur in RCCs and are associated with aggressive disease. The mutation is more frequent in renal pelvic cancer. Thus, the mutant TERT promoter found in urine may come from not only BC, but also RCC or UTUC.

TERT promoter mutations in clear cell renal cell carcinoma

We screened promoter region of the telomerase reverse transcriptase (TERT) for activating somatic mutations in 188 tumors from patients with clear cell renal cell carcinoma (ccRCC). Twelve tumors (6.4%) carried a mutation within the core promoter region of the gene. The mutations were less frequent in high grade tumors compared to low grade tumors [odds ratio (OR) = 0.15, 95% confidence interval (CI) = 0.03-0.72, p = 0.02]. Multivariate analysis for cause specific survival showed statistically significant poor outcome in patients with TERT promoter mutations [hazard ratio (HR) = 2.90, 95% CI = 1.13-7.39, p = 0.03]. A common polymorphism (rs2853669) within the locus seemed to act as a modifier of the effect of the mutations on patient survival as the noncarriers of the variant allele with the TERT promoter mutations showed worst survival (HR = 3.34, 95% CI = 1.24-8.98, p = 0.02). We also measured relative telomere length (RTL) in tumors and difference between tumors with and without the TERT promoter mutations was not statistically significant. Similarly, no difference in patient survival based on RTL in tumors was observed. Our study showed a relatively low frequency of TERT promoter mutations in ccRCC. Nevertheless, patients with the mutations, particularly in the absence of the rs2853669 variant showed the worst disease-specific survival. Thus, it is possible that the TERT promoter mutations define a small subset of tumors with an aggressive behavior.

Diagnostic and prognostic TERT promoter mutations in thyroid fine-needle aspiration biopsy

Two promoter mutations, chr5:1 295 228C>T and chr5:1 295 250C>T, in the gene for telomerase reverse transcriptase (TERT) have been recently identified in thyroid cancers and shown to be important in thyroid tumor pathogenesis. The diagnostic and prognostic potentials of testing for these mutations on thyroid fine-needle aspiration biopsy (FNAB) have not been investigated. Herein, we examined the two TERT promoter mutations along with the BRAF V600E mutation by direct DNA sequencing on 308 FNAB specimens preoperatively obtained from thyroid nodules with postoperatively confirmed pathological diagnoses. We found TERT promoter mutations in 0.0% (0/179) of benign thyroid nodules and 7.0% (9/129) of thyroid nodules of differentiated thyroid cancer, representing a 100% diagnostic specificity and 7.0% sensitivity, with the latter rising to 38.0% (49/129) when combined with BRAF V600E testing. Several TERT-promoter-mutation-positive thyroid nodules were cytologically indeterminate on FNAB. Approximately 80% of the TERT promoter mutation-positive thyroid nodules were thyroid cancers with aggressive clinicopathological behaviors, such as extrathyroidal invasion, lymph node metastases, distant metastases, disease recurrence or patient death. Thus, a positive TERT promoter mutation test not only definitively diagnoses a thyroid nodule as cancerous but also preoperatively identifies a cancer with aggressive potential. This is the first study, to our knowledge, of TERT promoter mutations on thyroid FNAB, demonstrating the value of this novel molecular testing in the diagnosis of thyroid nodules and preoperative risk stratification of thyroid cancer. Thus, testing of TERT promoter mutations on FNAB will enhance and improve the current molecular-based approaches to the management of thyroid nodules and thyroid cancer.

Molecular approaches to thyroid cancer diagnosis

Thyroid nodules are common, and the accurate diagnosis of cancer or benign disease is important for the effective clinical management of patients. Molecular markers are a helpful diagnostic tool, particularly for cytologically indeterminate thyroid nodules. In the past few years, significant progress has been made in developing molecular markers for clinical use in fine-needle aspiration specimens, including gene mutation panels and gene expression classifiers. With the availability of next generation sequencing technology, gene mutation panels can be expanded to interrogate multiple genes simultaneously and to provide yet more accurate diagnostic information. In addition, recently several new molecular markers of thyroid cancer have been identified that offer diagnostic, prognostic, and therapeutic information that might be of value in guiding individualized management of patients with thyroid nodules.

Update on anaplastic thyroid carcinoma: morphological, molecular, and genetic features of the most aggressive thyroid cancer

Anaplastic thyroid carcinoma (ATC) is the most aggressive form of thyroid cancer. It shows a wide spectrum of morphological presentations and the diagnosis could be challenging due to its high degree of dedifferentiation. Molecular and genetic features of ATC are widely heterogeneous as well and many efforts have been made to find a common profile in order to clarify its cancerogenetic process. A comprehensive review of the current literature is here performed, focusing on histopathological and genetic features.

Telomerase-dependent and independent telomere maintenance and its clinical implications in medullary thyroid carcinoma

CONTEXT

Telomere maintenance via telomerase activation and the alternative lengthening of telomeres (ALT) mechanism was assessed in medullary thyroid carcinoma.

SETTING AND DESIGN

In total, 42 medullary thyroid carcinomas (MTC) were studied including 24 rearranged during transfection (RET)- mutated cases. Relative telomerase reverse transcriptase (TERT) expression, splice forms, and telomere length were determined by PCR-based methods, and telomerase activity by ELISA. The ALT mechanism was detected by Southern blot analysis and immunofluorescence.

RESULTS

TERT expression and telomerase activity were detected in 21/42 tumors (50%), and was independent of the common somatic M918T RET mutation. Mean telomere length was shorter in MTCs compared with thyroids. Telomerase activation was associated with large tumor size (P = .027), advanced clinical stage (P = .0001), and short survival (P = .0001). Full-length TERT and the α(-) and β(-)-deletion forms were revealed, and the full-length form was associated with short survival (P = .04). A subset of cases without telomerase activation showed involvement of the ALT mechanism, which was associated with a low MIB-1 proliferation index (P = .024).

CONCLUSIONS

Stabilization of telomeres by telomerase activation occurs in half of the MTCs and by the ALT mechanism in a subset of cases. Telomerase activation may be used as an additional prognostic marker in medullary thyroid carcinoma.

BRAF V600E and TERT promoter mutations cooperatively identify the most aggressive papillary thyroid cancer with highest recurrence

PURPOSE

To investigate the prognostic value of the BRAF V600E mutation and the recently identified TERT promoter mutation chr5:1,295,228C>T (C228T), individually and in their coexistence, in papillary thyroid cancer (PTC).

PATIENTS AND METHODS

We performed a retrospective study of the relationship of BRAF and TERT C228T mutations with clinicopathologic outcomes of PTC in 507 patients (365 women and 142 men) age 45.9 ± 14.0 years (mean ± SD) with a median follow-up of 24 months (interquartile range, 8 to 78 months).

RESULTS

Coexisting BRAF V600E and TERT C228T mutations were more commonly associated with high-risk clinicopathologic characteristics of PTC than they were individually. Tumor recurrence rates were 25.8% (50 of 194;77.60 recurrences per 1,000 person-years; 95% CI, 58.81 to 102.38) versus 9.6% (30 of 313; 22.88 recurrences per 1,000 person-years; 95% CI, 16.00 to 32.72) in BRAF mutation-positive versus -negative patients (hazard ratio [HR], 3.22; 95% CI, 2.05 to 5.07) and 47.5% (29 of 61; 108.55 recurrences per 1,000 person-years; 95% CI, 75.43 to 156.20) versus 11.4% (51 of 446; 30.21 recurrences per 1,000 person-years; 95% CI, 22.96 to 39.74) in TERT mutation-positive versus -negative patients (HR, 3.46; 95% CI, 2.19 to 5.45). Recurrence rates were 68.6% (24 of 35; 211.76 recurrences per 1,000 person-years; 95% CI, 141.94 to 315.94) versus 8.7% (25 of 287; 21.60 recurrences per 1,000 person-years; 95% CI, 14.59 to 31.97) in patients harboring both mutations versus patients harboring neither mutation (HR, 8.51; 95% CI, 4.84 to 14.97), which remained significant after clinicopathologic cofactor adjustments. Disease-free patient survival curves displayed a moderate decline with BRAF V600E or TERT C228T alone but a sharp decline with two coexisting mutations.

CONCLUSION

Coexisting BRAF V600E and TERT C228T mutations form a novel genetic background that defines PTC with the worst clinicopathologic outcomes, providing unique prognostic and therapeutic implications.

TERT promoter mutations and their association with BRAF V600E mutation and aggressive clinicopathological characteristics of thyroid cancer

CONTEXT

Promoter mutations chr5:1,295,228C>T and chr5:1,295,250C>T (termed C228T and C250T, respectively) in the gene for telomerase reverse transcriptase (TERT) have been reported in various cancers and need to be further investigated in thyroid cancer.

OBJECTIVE

The aim of the study was to explore TERT promoter mutations in various thyroid tumors and examine their relationship with BRAF V600E mutation, iodine intake, and clinicopathological behaviors of thyroid cancer.

DESIGN

TERT promoter and BRAF mutations were identified by sequencing genomic DNA of primary thyroid tumors from normal- and high-iodine regions in China, and clinicopathological correlation was analyzed.

RESULTS

The C228T mutation was found in 9.6% (39 of 408) of papillary thyroid cancer (PTC), C250T was found in 1.7% (7 of 408) of PTC, and they were collectively found in 11.3% (46 of 408) of PTC. C228T was found in 31.8% (7 of 22) and C250T in 4.6% (1 of 22) of follicular thyroid cancer (FTC), and they were collectively found in 36.4% (8 of 22) of FTC. No TERT mutation was found in 44 benign thyroid tumors. The two mutations occurred in 3.8% (6 of 158) of BRAF mutation-negative PTC vs 16.0% (40 of 250) of BRAF mutation-positive PTC (P = 5.87 × 10(-4)), demonstrating their association. Unlike BRAF mutation, TERT promoter mutations were not associated with high iodine intake, but they were associated with older patient age, larger tumor size, extrathyroidal invasion, and advanced stages III/IV of PTC. Coexisting TERT and BRAF mutations were even more commonly and more significantly associated with clinicopathological aggressiveness.

CONCLUSIONS

In this large cohort, we found TERT promoter mutations to be common, particularly in FTC and BRAF mutation-positive PTC, and associated with aggressive clinicopathological characteristics.

The activating TERT promoter mutation C228T is recurrent in subsets of adrenal tumors

The telomerase reverse transcriptase gene (TERT) encodes the reverse transcriptase component of the telomerase complex, which is essential for telomere stabilization and cell immortalization. Recent studies have demonstrated a transcriptional activation role for the TERT promoter mutations C228T and C250T in many human cancers, as well as a role in aggressive disease with potential clinical applications. Although telomerase activation is known in adrenal tumors, the underlying mechanisms are not established. We assessed C228T and C250T TERT mutations by direct Sanger sequencing in tumors of the adrenal gland, and further evaluated potential associations with clinical parameters and telomerase activation. A total of 199 tumors were evaluated, including 34 adrenocortical carcinomas (ACC), 47 adrenocortical adenomas (ACA), 105 pheochromocytomas (PCC; ten malignant and 95 benign), and 13 abdominal paragangliomas (PGL; nine malignant and four benign). TERT expression levels were determined by quantitative RT-PCR. The C228T mutation was detected in 4/34 ACCs (12%), but not in any ACA (P=0.028). C228T was also observed in one benign PCC and in one metastatic PGL. The C250T mutation was not observed in any case. In the ACC and PGL groups, TERT mutation-positive cases exhibited TERT expression, indicating telomerase activation; however, since expression was also revealed in TERT WT cases, this could denote additional mechanisms of TERT activation. To conclude, the TERT promoter mutation C228T is a recurrent event associated with TERT expression in ACCs, but rarely occurs in PGL and PCC. The involvement of the TERT gene in ACC represents a novel mutated gene in this entity.

TERT promoter mutations are a major indicator of poor outcome in differentiated thyroid carcinomas

CONTEXT

Telomerase promoter mutations (TERT) were recently described in follicular cell-derived thyroid carcinomas (FCDTC) and seem to be more prevalent in aggressive cancers.

OBJECTIVES

We aimed to evaluate the frequency of TERT promoter mutations in thyroid lesions and to investigate the prognostic significance of such mutations in a large cohort of patients with differentiated thyroid carcinomas (DTCs).

DESIGN

This was a retrospective observational study.

SETTING AND PATIENTS

We studied 647 tumors and tumor-like lesions. A total of 469 patients with FCDTC treated and followed in five university hospitals were included. Mean follow-up (±SD) was 7.8 ± 5.8 years.

MAIN OUTCOME MEASURES

Predictive value of TERT promoter mutations for distant metastasization, disease persistence at the end of follow-up, and disease-specific mortality.

RESULTS

TERT promoter mutations were found in 7.5% of papillary carcinomas (PTCs), 17.1% of follicular carcinomas, 29.0% of poorly differentiated carcinomas, and 33.3% of anaplastic thyroid carcinomas. Patients with TERT-mutated tumors were older (P < .001) and had larger tumors (P = .002). In DTCs, TERT promoter mutations were significantly associated with distant metastases (P < .001) and higher stage (P < .001). Patients with DTC harboring TERT promoter mutations were submitted to more radioiodine treatments (P = .009) with higher cumulative dose (P = .004) and to more treatment modalities (P = .001). At the end of follow-up, patients with TERT-mutated DTCs were more prone to have persistent disease (P = .001). TERT promoter mutations were significantly associated with disease-specific mortality [in the whole FCDTC (P < .001)] in DTCs (P < .001), PTCs (P = .001), and follicular carcinomas (P < .001). After adjusting for age at diagnosis and gender, the hazard ratio was 10.35 (95% confidence interval 2.01-53.24; P = .005) in DTC and 23.81 (95% confidence interval 1.36-415.76; P = .03) in PTCs.

CONCLUSIONS

TERT promoter mutations are an indicator of clinically aggressive tumors, being correlated with worse outcome and disease-specific mortality in DTC. TERT promoter mutations have an independent prognostic value in DTC and, notably, in PTC.

Telomerase reverse transcriptase promoter mutations in primary cutaneous melanoma

We previously reported a disease segregating causal germline mutation in a melanoma family and recurrent somatic mutations in metastasized tumours from unrelated patients in the core promoter region of the telomerase reverse transcriptase (TERT) gene. Here we show that the TERT promoter mutations, besides causing an increased gene expression, associate with increased patient age, increased Breslow thickness and tumour ulceration in 287 primary melanomas. The mutations are more frequent at both intermittently and chronically sun-exposed sites than non-exposed sites and tend to co-occur with BRAF and CDKN2A alterations. The association with parameters generally connected with poor outcome, coupled with high recurrence and mechanistic relevance, raises the possibility of the eventual use of TERT promoter mutations in the disease management.