Clinical implications of TERT promoter mutation on IDH mutation and MGMT promoter methylation in diffuse gliomas

Prognostic Impact of TERT Promoter Mutations in Adult-Type Diffuse Gliomas Based on WHO2021 Criteria

Mutation in the telomerase reverse transcriptase promoter (TERTp )is commonly observed in various malignancies, such as central nervous system (CNS) tumors, malignant melanoma, bladder cancer, and thyroid carcinoma. These mutations are recognized as significant poor prognostic factors for these tumors. In this investigation, a total of 528 cases of adult-type diffuse gliomas diagnosed at a single institution were reclassified according to the 2021 WHO classifications of CNS tumors, 5th edition (WHO2021). The study analyzed clinicopathological and genetic features, including TERTp mutations in each tumor. The impact of known prognostic factors on patient outcomes was analyzed through Kaplan-Meier survival and Cox regression analysis. TERTp mutations were predominantly identified in 94.1% of oligodendrogliomas (ODG), followed by 66.3% in glioblastoma, IDH-wildtype (GBM-IDHwt), and 9.2% of astrocytomas, IDH-mutant (A-IDHm). When considering A-IDHm and GBM as astrocytic tumors (Group 1) and ODGs (Group 2), TERTp mutations emerged as a significant adverse prognostic factor (p = 0.013) in Group 1. However, within each GBM-IDHwt and A-IDHm, the presence of TERTp mutations did not significantly impact patient prognosis (p = 0.215 and 0.268, respectively). Due to the high frequency of TERTp mutations in Group 2 (ODG) and their consistent prolonged survival, a statistical analysis to evaluate their impact on overall survival was deemed impractical. When considering MGMTp status, the combined TERTp-mutated and MGMTp-unmethylated group exhibited the worst prognosis in OS (p = 0.018) and PFS (p = 0.034) of GBM. This study confirmed that the classification of tumors according to the WHO2021 criteria effectively reflected prognosis. Both uni- and multivariate analyses in GBM, age, MGMTp methylation, and CDKN2A/B homozygous deletion were statistically significant prognostic factors while in univariate analysis in A-IDHm, grade 4, the Ki-67 index and MYCN amplifications were statistically significant prognostic factors. This study suggests that it is important to classify and manage tumors based on their genetic characteristics in adult-type diffuse gliomas.

Development and validation of clinical-radiomics analysis for preoperative prediction of IDH mutation status and WHO grade in diffuse gliomas: a consecutive L-[methyl-11C] methionine cohort study with two PET scanners

PURPOSE

Determination of isocitrate dehydrogenase (IDH) genotype is crucial in the stratification of diagnosis and prognostication in diffuse gliomas. We sought to build and validate radiomics models and clinical features incorporated nomogram for preoperative prediction of IDH mutation status and WHO grade of diffuse gliomas with L-[methyl-11C] methionine ([11C]MET) PET/CT imaging according to the 2016 WHO classification of tumors of the central nervous system.

METHODS

Consecutive 178 preoperative [11C]MET PET/CT images were retrospectively studied for radiomics analysis. One hundred six patients from PET scanner 1 were used as training dataset, and 72 patients from PET scanner 2 were used for validation dataset. [11C]MET PET and integrated CT radiomics features were extracted, respectively; three independent predictive models were built based on PET features, CT features, and combined PET/CT features, respectively. The SelectKBest method, Spearman correlation analysis, Least Absolute Shrinkage and Selection Operator (LASSO) regression, and machine learning algorithms were applied for feature selection and model building. After filtering the satisfactory predictive model, key clinical features were incorporated for the nomogram establishment.

RESULTS

The combined [11C]MET PET/CT radiomics model, which consisted of four PET features and eight integrated CT features, was significantly associated with IDH genotype (p < 0.0001 for both training and validation datasets). Nomogram based on the [11C]MET PET/CT radiomics score, patients' age, and dichotomous tumor location status showed satisfactory discrimination capacity, and the AUC was 0.880 (95% CI, 0.726-0.998) in the training dataset and 0.866 (95% CI, 0.777-0.956) in the validation dataset. In IDH stratified WHO grade prediction, the final radiomics model consists of four PET features and two CT features had reasonable and stable differential efficacy of WHO grade II and III patients from grade IV patients in IDH-wildtype patients, and the AUC was 0.820 (95% CI, 0.541-1.000) in the training dataset and 0.766 (95% CI, 0.612-0.921) in the validation dataset.

CONCLUSION

[11C]MET PET radiomics features could benefit non-invasive IDH genotype prediction, and integrated CT radiomics features could enhance the efficacy. Radiomics and clinical features incorporation could establish satisfactory nomogram for clinical application. This non-invasive predictive investigation based on our consecutive cohort from two PET scanners could provide the perspective to observe the differential efficacy and the stability of radiomics-based investigation in untreated diffuse gliomas.

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.

Cellular senescence in glioma

INTRODUCTION

Glioma is the most common primary brain tumor and is often associated with treatment resistance and poor prognosis. Standard treatment typically involves radiotherapy and temozolomide-based chemotherapy, both of which induce cellular senescence-a tumor suppression mechanism.

DISCUSSION

Gliomas employ various mechanisms to bypass or escape senescence and remain in a proliferative state. Importantly, senescent cells remain viable and secrete a large number of factors collectively known as the senescence-associated secretory phenotype (SASP) that, paradoxically, also have pro-tumorigenic effects. Furthermore, senescent cells may represent one form of tumor dormancy and play a role in glioma recurrence and progression.

CONCLUSION

In this article, we delineate an overview of senescence in the context of gliomas, including the mechanisms that lead to senescence induction, bypass, and escape. Furthermore, we examine the role of senescent cells in the tumor microenvironment and their role in tumor progression and recurrence. Additionally, we highlight potential therapeutic opportunities for targeting senescence in glioma.

Association of human telomerase reverse transcriptase promoter mutation with unfavorable prognosis in glioma: A systematic review and meta-analysis

Background

Glioma is one of the most malignant and aggressive tumors, with an extremely poor prognosis. Human telomerase reverse transcriptase (hTERT) promoter mutation is regarded as a risk factor in tumor growth. Although the prevalence of hTERT promoter (pTERT) mutation in gliomas has been investigated, the results are inconsistent. This meta-analysis aims to investigate the prognostic value of hTERT in glioma patients and its interaction with other biomarkers.

Materials and Methods

We searched 244 citations from four databases: PubMed (2000-2021), Web of Science (2000-2021), Embase (2010-2021), and Cochrane Library (2000-2021) with 28 articles included.

Results

We calculated hazard ratios (HRs) using the random effect model and the pooled result suggested that TERT promoter mutation predicted poorer overall survival (HR: 1.53, 95% confidence interval [CI]: 1.34-1.75, P < 0.001, I2: 49.9%, pheterogeneity:0.002) and progression-free survival (HR: 1.55, 95% CI: 1.27-1.88, P < 0.001, I2: 0.0%, pheterogeneity: 0.473). For subgroup analysis, we analyzed multiple factors including iso-citrate dehydrogenase (IDH) genotype, age, diagnosis, pTERT region, so as to locate the sources of heterogeneity. Interestingly, in IDH mutant subgroup, pTERT mutation became a beneficial prognostic factor (HR: 0.73, 95% CI: 0.57-0.93, I2: 22.3%, pheterogeneity: 0.277), which is contrary to the results in pooled analysis.

Conclusion

In general, pTERT mutation may result in shorter survival time in glioma patients, but longer survival time when glioma patients are combined with IDH mutation.

Deep Learning Prediction of TERT Promoter Mutation Status in Thyroid Cancer Using Histologic Images

Background and objectives: Telomerase reverse transcriptase (TERT) promoter mutation, found in a subset of patients with thyroid cancer, is strongly associated with aggressive biologic behavior. Predicting TERT promoter mutation is thus necessary for the prognostic stratification of thyroid cancer patients. Materials and Methods: In this study, we evaluate TERT promoter mutation status in thyroid cancer through the deep learning approach using histologic images. Our analysis included 13 consecutive surgically resected thyroid cancers with TERT promoter mutations (either C228T or C250T) and 12 randomly selected surgically resected thyroid cancers with a wild-type TERT promoter. Our deep learning model was created using a two-step cascade approach. First, tumor areas were identified using convolutional neural networks (CNNs), and then TERT promoter mutations within tumor areas were predicted using the CNN–recurrent neural network (CRNN) model. Results: Using the hue–saturation–value (HSV)-strong color transformation scheme, the overall experiment results show 99.9% sensitivity and 60% specificity (improvements of approximately 25% and 37%, respectively, compared to image normalization as a baseline model) in predicting TERT mutations. Conclusions: Highly sensitive screening for TERT promoter mutations is possible using histologic image analysis based on deep learning. This approach will help improve the classification of thyroid cancer patients according to the biologic behavior of tumors.

Gliomas molecular markers: importance in treatment, prognosis and applicability in brazilian health system

Gliomas represent 80% of all primary malignant brain tumors in adults. In view of this public health problem, the early detection through sensitive and specific molecular tumor markers analysis can help to improve gliomas diagnosis and prognosis as well as their staging, assessment of therapeutic response and detection of recurrence. Therefore, this review focuses in current gliomas tumor markers, IDH-1/2, 1p/19q, MGMT, ATRX, TERT, H3, EGFR, BRAF and Ki67 used in clinic worldwide and their importance to early detection, glioma histological and molecular classification as well as in predicting patient's therapeutic response. In addition, we present what are the steps in the requesting process for this type of examination in the Brazilian Public Health System (SUS) scope, which attends most of the Brazilian population. Thereby, this article is useful in demonstrating which markers are used in the clinical practice for glioma patients and can be performed in the SUS through partnerships/agreements between specialized health centers and clinical analysis laboratories. It is hoped that this work clarifies, the necessary subsidies to carry out the research of tumor markers in all institutions that serve SUS users, providing a service with equal conditions.

Molecular Characterization of IDH Wild-type Diffuse Astrocytomas: The Potential of cIMPACT-NOW Guidelines

IDH wild-type (wt) grade 2/3 astrocytomas are a heterogenous group of tumors with disparate clinical and molecular profiles. cIMPACT-NOW recommendations incorporated in the new 2021 World Health Organization (WHO) Classification of Central Nervous System (CNS) Tumors urge minimal molecular criteria to identify a subset that has an aggressive clinical course similar to IDH -wt glioblastomas (GBMs). This paper describes the use of a panel of molecular markers to reclassify IDH -wt grade 2/3 diffuse astrocytic gliomas (DAGs) and study median overall survival concerning for to IDH -wt GBMs in the Indian cohort. IDH -wt astrocytic gliomas (grades 2, 3, and 4) confirmed by IDHR132H immunohistochemistry and IDH1/2 gene sequencing, 1p/19q non-codeleted with no H3F3A mutations were included. TERT promoter mutation by Sanger sequencing, epidermal growth factor receptor amplification, and whole chromosome 7 gain and chromosome 10 loss by fluorescence in situ hybridization was assessed and findings correlated with clinical and demographic profiles. The molecular profile of 53 IDH -wt DAGs (grade 2: 31, grade 3: 22) was analyzed. Eleven cases (grade 2: 8, grade 3: 3) (20.75%) were reclassified as IDH -wt GBMs, WHO grade 4 ( TERT promoter mutation in 17%, epidermal growth factor receptor amplification in 5.5%, and whole chromosome 7 gain and chromosome 10 loss in 2%). Molecular GBMs were predominantly frontal (54.5%) with a mean age of 36 years and median overall survival equivalent to IDH -wt GBMs (18 vs. 19 mo; P =0.235). Among grade 2/3 DAGs not harboring these alterations, significantly better survival was observed for grade 2 versus grade 3 DAGs (25 vs. 16 mo; P =0.002). Through the incorporation of a panel of molecular markers, a subset of IDH -wt grade 2 DAGs can be stratified into molecular grade 4 tumors with prognostic and therapeutic implications. However, IDH -wt grade 3 DAGs behave like GBMs irrespective of molecular profile.

Nano-Codelivery of Temozolomide and siPD-L1 to Reprogram the Drug-Resistant and Immunosuppressive Microenvironment in Orthotopic Glioblastoma

Glioblastoma (GBM) is an invasive cancer with high mortality in central nervous system. Resistance to temozolomide (TMZ) and immunosuppressive microenvironment lead to low outcome of the standardized treatment for GBM. In this study, a 2-deoxy-d-glucose modified lipid polymer nanoparticle loaded with TMZ and siPD-L1 (TMZ/siPD-L1@GLPN/dsb) was prepared to reprogram the TMZ-resistant and immunosuppressive microenvironment in orthotopic GBM. TMZ/siPD-L1@GLPN/dsb simultaneously delivered a large amount of TMZ and siPD-L1 to the deep area of the orthotopic TMZ-resistant GBM tissue. By inhibiting PD-L1 protein expression, TMZ/siPD-L1@GLPN/dsb markedly augmented the percentage of CD3⁺CD8⁺IFN-γ⁺ cells (T_eff cells) and reduced the percentage of CD4⁺CD25⁺FoxP3⁺ cells (T_reg cells) in orthotopic TMZ-resistant GBM tissue, which enhanced T-cell mediated cytotoxicity on orthotopic TMZ-resistant GBM. Moreover, TMZ/siPD-L1@GLPN/dsb obviously augmented the sensitivity of orthotopic TMZ-resistant GBM to TMZ through decreasing the protein expression of O⁶-methyl-guanine-DNA methyltransferase (MGMT) in TMZ-resistant GBM cells. Thus, TMZ/siPD-L1@GLPN/dsb markedly restrained the growth of orthotopic TMZ-resistant GBM and extended the survival time of orthotopic GBM rats through reversing a TMZ-resistant and immunosuppressive microenvironment. TMZ/siPD-L1@GLPN/dsb shows potential application to treat orthotopic TMZ-resistant GBM.

Molecular Biomarker Testing for the Diagnosis of Diffuse Gliomas

CONTEXT.—

The diagnosis and clinical management of patients with diffuse gliomas (DGs) have evolved rapidly over the past decade with the emergence of molecular biomarkers that are used to classify, stratify risk, and predict treatment response for optimal clinical care.

OBJECTIVE.—

To develop evidence-based recommendations for informing molecular biomarker testing for pediatric and adult patients with DGs and provide guidance for appropriate laboratory test and biomarker selection for optimal diagnosis, risk stratification, and prediction.

DESIGN.—

The College of American Pathologists convened an expert panel to perform a systematic review of the literature and develop recommendations. A systematic review of literature was conducted to address the overarching question, "What ancillary tests are needed to classify DGs and sufficiently inform the clinical management of patients?" Recommendations were derived from quality of evidence, open comment feedback, and expert panel consensus.

RESULTS.—

Thirteen recommendations and 3 good practice statements were established to guide pathologists and treating physicians on the most appropriate methods and molecular biomarkers to include in laboratory testing to inform clinical management of patients with DGs.

CONCLUSIONS.—

Evidence-based incorporation of laboratory results from molecular biomarker testing into integrated diagnoses of DGs provides reproducible and clinically meaningful information for patient management.

Detection of TERT Promoter Mutations as a Prognostic Biomarker in Gliomas: Methodology, Prospects, and Advances

This article reviews the existing approaches to determining the TERT promoter mutational status in patients with various tumoral diseases of the central nervous system. The operational characteristics of the most common methods and their transferability in medical practice for the selection or monitoring of personalized treatments based on the TERT status and other related molecular biomarkers in patients with the most common tumors, such as glioblastoma, oligodendroglioma, and astrocytoma, are compared. The inclusion of new molecular markers in the course of CNS clinical management requires their rapid and reliable assessment. Availability of molecular evaluation of gliomas facilitates timely decisions regarding patient follow-up with the selection of the most appropriate treatment protocols. Significant progress in the inclusion of molecular biomarkers for their subsequent clinical application has been made since 2016 when the WHO CNS classification first used molecular markers to classify gliomas. In this review, we consider the methodological approaches used to determine mutations in the promoter region of the TERT gene in tumors of the central nervous system. In addition to classical molecular genetical methods, other methods for determining TERT mutations based on mass spectrometry, magnetic resonance imaging, next-generation sequencing, and nanopore sequencing are reviewed with an assessment of advantages and disadvantages. Beyond that, noninvasive diagnostic methods based on the determination of the mutational status of the TERT promoter are discussed.

Prognostic Impact of the Combination of MGMT Methylation and TERT Promoter Mutation in Glioblastoma

Background  The concept of combinational analysis between the methylation of O ⁶ -methylguanine-DNA methyltransferase ( MGMT ) and telomerase reverse transcriptase promoter ( pTERT ) mutation in glioblastoma (GBM) has been reported. The main study objective was to determine the prognosis of patients with GBM based on MGMT/pTERT classification, while the secondary objective was to estimate the temozolomide effect on the survival time of GBM with MGMT/pTERT classification. Methods  A total of 50 GBM specimens were collected after tumor resection and were selected for investigating MGMT methylation and pTERT mutation. Clinical imaging and pathological characteristics were retrospectively analyzed. Patients with MGMT/pTERT classification were analyzed using survival analysis to develop the nomogram for forecasting and individual prognosis. Results  All patients underwent resection (total resection: 28%, partial resection: 64%, biopsy: 8%). Thirty-two percent of all cases received adjuvant temozolomide with radiotherapy. Sixty-four percent of the case was found methylated MGMT , and 56% of the present cohort found pTERT mutation. Following combinational analysis of biomarkers, results showed that the GBMs with methylated MGMT and wild-type pTERT had a superior prognosis compared with other subtypes. Using Cox regression analysis with multivariable analysis, the extent of resection, postoperative chemoradiotherapy, MGMT/pTERT classification were associated with a favorable prognosis. Hence, a web-based nomogram was developed for deploying individual prognostication. Conclusions  The interaction of MGMT methylation and pTERT mutation was confirmed for predicting prognosis. The results from the present study could help physicians create treatment strategies for GBM patients in real-world situations.

Estimation of the occurrence rates of IDH1 and IDH2 mutations in gliomas and the reconsideration of IDH-wildtype anaplastic astrocytomas: an institutional experience

Objectives

Most diffuse gliomas are reported to harbor isocitrate dehydrogenase (IDH) mutations. However, when these mutations are tested in clinical practice, the results are often negative.

Methods

This study examined the frequency of IDH1 and IDH2 mutations in gliomas classified according to the revised 2016 World Health Organization classification, and investigated their prognostic relevance. We tested 87 gliomas for IDH1 and IDH2 mutations using the peptide nucleic acid clamp method.

Results

IDH1 mutations were observed in 42% of diffuse astrocytomas, 23% of anaplastic astrocytomas, all oligodendrogliomas and anaplastic oligodendrogliomas, and 17% of glioblastomas. An IDH2 mutation was identified in one case of diffuse astrocytoma. In the survival analysis of diffuse astrocytic tumors, patients with IDH1/2-wildtype anaplastic astrocytomas tended to have a poor prognosis, similar to that of glioblastomas.

Conclusions

IDH2 mutations were infrequent in gliomas. In anaplastic astrocytomas, the frequency of IDH1/2-wildtype was relatively high, and the prognosis of patients with this type of tumor was very similar to that of those with glioblastomas. It may therefore be necessary to reconsider the classification and treatment strategies for IDH1/2-wildtype anaplastic astrocytomas.

Glioblastoma Primary Cells Retain the Most Copy Number Alterations That Predict Poor Survival in Glioma Patients

Gliomas are solid tumors that originate from glial cells in the brain or spine and account for 74.6% of malignant primary central nervous system tumors worldwide. As patient-derived primary cells are important tools for drug screening and new therapy development in glioma, we aim to understand the genomic similarity of the primary cells to their parental tumors by comparing their whole-genome copy number variations and expression profile of glioma clinicopathologic factors. We found that the primary cells from grade II/III gliomas lost most of the gene copy number alterations (CNAs), which were mainly located on chromosome 1p and 19q in their parental tumors. The glioblastoma (GBM) primary cells preserved 83.7% of the gene CNAs in the parental GBM tumors, including chromosome 7 gain and 10q loss. The CNA gains of LINC00226 and ADAM6 and the chromosome 16p11 loss were reconstituted in primary cells from both grade II/III gliomas and GBMs. Interestingly, we found these CNAs were correlated to overall survival (OS) in glioma patients using the Merged Cohort LGG and GBM dataset from cBioPortal. The gene CNAs preserved in glioma primary cells often predicted poor survival, whereas the gene CNAs lost in grade II/III primary cells were mainly associated to better prognosis in glioma patients. Glioma prognostic factors that predict better survival, such as IDH mutations and 1p/19q codeletion in grade II/III gliomas, were lost in their primary cells, whereas methylated MGMT promoters as well as TERT promoter mutations were preserved in GBM primary cells while lost in grade II/III primary cells. Our results suggest that GBM primary cells tend to preserve CNAs in their parental tumors, and these CNAs are correlated to poor OS and predict worse prognosis in glioma patients.

Living with a central nervous system (CNS) tumor: findings on long-term survivorship from the NIH Natural History Study

Background

Primary central nervous system (CNS) tumors are often associated with high symptom burden and a poor prognosis from the time of diagnosis. The purpose of this study is to describe patient-reported outcomes (PRO) data from long-term survivors (LTS; ≥5-year survival post-diagnosis).

Methods

Clinical/treatment/molecular characteristics and PROs (symptom burden/interference (MDASI-BT/SP), perceived cognition (Neuro-QoL), anxiety/depression (PROMIS), and general health status (EQ-5D-3L)) were collected on 248 adult LTS between 9/2016 and 8/2019. Descriptive statistics and regression analysis were used to report results.

Results

Participants had a median age of 47 years (19-82) and were primarily White (83%) males (51%) with high-grade tumors (59%) and few mutations. Forty-two percent of the 222 brain tumor LTS reported no moderate-to-severe symptoms, whereas 45% reported three or more; most common symptoms were fatigue (40%), difficulty remembering (29%), and drowsiness (28%). Among spine tumor LTS (n = 42), nearly half reported moderate-to-severe weakness, pain, fatigue, and numbness/tingling, with 72% experiencing activity-related interference. Severe anxiety, depression, and cognitive symptoms were reported in up to 23% of the sample. Brain tumor LTS at higher risk for severe symptoms were more likely to be young, unemployed, and have poor KPS (Karnofsky Performance Status), whereas high symptom-risk spinal cord tumor LTS had poor KPS and received any tumor treatment.

Conclusions

Findings indicate LTS fall into distinct cohorts with no significant symptoms or very high symptom burden, regardless of tumor grade or mutational profile. These LTS data demonstrate the need for survivorship care programs and future studies to explore the symptom trajectory of all CNS tumor patients for prevention and early interventions.

TERT Promoter Alterations in Glioblastoma: A Systematic Review

Simple Summary

Glioblastoma is the most common malignant primary brain tumor in adults. Glioblastoma accounts for 2 to 3 cases per 100,000 persons in North America and Europe. Glioblastoma classification is now based on histopathological and molecular features including isocitrate dehydrogenase (IDH) mutations. At the end of the 2000s, genome-wide sequencing of glioblastoma identified recurrent somatic genetic alterations involved in oncogenesis. Among them, the alterations in the promoter region of the telomerase reverse transcriptase (TERTp) gene are highly recurrent and occur in 70% to 80% of all glioblastomas, including glioblastoma IDH wild type and glioblastoma IDH mutated. This review focuses on recent advances related to physiopathological mechanisms, diagnosis, and clinical implications.

Abstract

Glioblastoma, the most frequent and aggressive primary malignant tumor, often presents with alterations in the telomerase reverse transcriptase promoter. Telomerase is responsible for the maintenance of telomere length to avoid cell death. Telomere lengthening is required for cancer cell survival and has led to the investigation of telomerase activity as a potential mechanism that enables cancer growth. The aim of this systematic review is to provide an overview of the available data concerning TERT alterations and glioblastoma in terms of incidence, physiopathological understanding, and potential therapeutic implications.

Human TERT promoter mutations as a prognostic biomarker in glioma

The TERT promoter (pTERT) mutations, C228T and C250T, play a significant role in malignant transformation by telomerase activation, oncogenesis and immortalisation of cells. C228T and C250T are emerging as important biomarkers in many cancers including glioblastoma multiforme (GBM), where the prevalence of these mutations is as high as 80%. Additionally, the rs2853669 single nucleotide polymorphism (SNP) may cooperate with these pTERT mutations in modulating progression and overall survival in GBM. Using liquid biopsies, pTERT mutations, C228T and C250T, and other clinically relevant biomarkers can be easily detected with high precision and sensitivity, facilitating longitudinal analysis throughout therapy and aid in cancer patient management.

In this review, we explore the potential for pTERT mutation analysis, via liquid biopsy, for its potential use in personalised cancer therapy. We evaluate the relationship between pTERT mutations and other biomarkers as well as their potential clinical utility in early detection, prognostication, monitoring of cancer progress, with the main focus being on brain cancer.

The interaction between TERT promoter mutation and MGMT promoter methylation on overall survival of glioma patients: a meta-analysis

Background

There are controversial results concerning the prognostic implication of TERT promoter mutation in glioma patients concerning MGMT status. In this meta-analysis, we investigated whether there are any interactions of these two genetic markers on the overall survival (OS) of glioma patients.

Methods

Electronic databases including PubMed and Web of Science were searched for relevant studies. Hazard ratio (HR) and its 95% confidence interval (CI) for OS adjusted for selected covariates were calculated from the individual patient data (IPD), Kaplan-Meier curve (KMC), or directly obtained from the included studies.

Results

A total of nine studies comprising 2819 glioma patients were included for meta-analysis. Our results showed that TERT promoter mutation was associated with a superior outcome in MGMT-methylated gliomas (HR = 0.73; 95% CI = 0.55–0.98; p-value = 0.04), whereas this mutation was associated with poorer survival in gliomas without MGMT methylation (HR = 1.86; 95% CI = 1.54–2.26; p-value < 0.001). TERT-mutated glioblastoma (GBM) patients with MGMT methylation benefited from temozolomide (TMZ) treatment (HR = 0.33; 95% CI = 0.23–0.47; p-value < 0.001). MGMT methylation was not related with any improvement in OS in TERT-wild type GBMs (HR = 0.80; 95% CI = 0.56–1.15; p-value = 0.23).

Conclusions

The prognostic value of TERT promoter mutation may be modulated by MGMT methylation status. Not all MGMT-methylated GBM patients may benefit from TMZ; it is possible that only TERT-mutated GBM with MGMT methylation, in particular, may respond.

Negative Prognostic Implication of TERT Promoter Mutations in Human Papillomavirus-Negative Tonsillar Squamous Cell Carcinoma Under the New 8th AJCC Staging System

Telomerase reverse transcriptase gene promoter (TERTp) mutation is a potential candidate for pathogenesis and therapeutic target of tonsillar squamous cell carcinomas (TSCCs) in association with human papillomavirus (HPV). Their clinical relevance has not been validated under the new 8th American Joint Committee on Cancer (AJCC) staging system. We analyzed real-time peptide nucleic acid–mediated PCR and sequencing methods (TERTp mutation) and real-time PCR-based assay (HPV) in 80 surgically resected TSCCs. The 8th edition staging system improved the stratification of the early and advanced stages and between T or N categories for overall survival over the 7th edition. TERTp mutation was found in 7.5%, and HPV in 80.0% of the patients. The majority (83.3%) of TERTp mutation cases were HPV-positive TSCCs. Applying the 8th edition staging system, TERTp mutation was an independent factor of poor prognosis for disease-free survival (DFS) in TSCC patients, supporting the clinical significance of TERTp mutation in tonsil cancer. TERTp mutations were also negatively correlated with overall survival and DFS in HPV-negative TSCCs. Conclusively, TERTp mutation provides negative prognostic impact on survival of surgically managed tonsil cancers staged with the AJCC 8th edition.

Alkaloids of fascaplysin are promising chemotherapeutic agents for the treatment of glioblastoma: Review

Glioblastoma is one of the most aggressive human brain tumors. Even following all the modern protocols of complex treatment, the median patient survival typically does not exceed 15 months. This review analyzes the main reasons for glioblastoma resistance to therapy, as well as attempts at categorizing the main approaches to increasing chemotherapy efficiency. Special emphasis is placed on the specific group of compounds, known as marine alkaloids and their synthetic derivatives exerting a general antitumor effect on glioblastoma cells. The unique mechanisms of marine alkaloid influence on the tumor cells prompt considering them as a promising basis for creating new chemotherapeutic agents for glioblastoma treatment.

Characteristics of the isocitrate dehydrogenase gene and telomerase reverse transcriptase promoter mutations in gliomas in Chinese patients

OBJECTIVES

To explore the characteristics of IDH and TERT promoter mutations in gliomas in Chinese patients.

METHODS

A total of 124 Chinese patients with gliomas were enrolled to study the frequencies of mutations in isocitrate dehydrogenase (IDH) and telomerase reverse transcriptase promoter (TERTp). Among the 124 patients, 59 patients were enrolled to study the classification of gliomas based on mutations in IDH and TERTp.

RESULTS

Isocitrate dehydrogenase mutations are positively correlated with a good prognosis but mutations in TERTp cannot predict prognoses independently. The combined analysis of the mutations of IDH and TERTp can predict the prognosis more accurately. Patients with IDH and TERTp glioma mutations have the best prognosis, followed by only IDH mutation patients and only TERTp mutation patients, which have the worst prognosis. IDH and TERTp mutations occur frequently in males, younger patients or lower-grade patients. In contrast, only TERTp mutations occur frequently in females, older patients or higher-grade patients.

CONCLUSIONS

Patients with IDH and TERTp glioma mutations have the best prognosis, and only IDH mutation patients and only TERTp mutation patients have the worst prognosis. Moreover, the molecular classification of gliomas by mutations of IDH and TERTp is not suitable for pediatric patients.

Is There an Independent Role of TERT and NF1 in High Grade Gliomas?

BACKGROUND: High grade glioma molecular profiling is of particular interest in neurooncology. The role of telomerase reverse transcriptase (TERT) varies dependent upon other molecular parameters. We explored the role of TERT in 101 high-grade gliomas. METHODS: A total of 101 patients (pts) with grade III–IV gliomas treated with standard of care and informative tumor genotypes were included in the present study. Of 55 genes targeted with the next-generation sequencing panel, mutations (muts) were found in 37; these were included in the analysis. TERT mut were tested with Sanger sequencing. MGMT promoter methylation status was determined by methylation specific PCR. RESULTS: 270 mut were detected in 92/101 tumors (91.1%). TERT was the most frequently mutated gene (74.3%). IDH1/2 mut were mutually exclusive with mut in the neurofibromin 1 (NF1) gene. Mutated TERT was associated with wild-type (wt) IDH1/2 (p = 0.025). The 12-month overall survival (OS) rate was 74.3% (median OS: 22 months). Pts with TERT and NF1 wt had a median OS of 40.8 months, while among pts with NF1 wt/TERT mutant, the median OS was 18.5 months. NF1 and TERT mut univariately conferred shorter OS (HR = 3.19; p = 0.004 and HR = 2.28; p = 0.002). Upon multivariate analysis, mutated TERT showed marginal unfavorable prognostic significance for OS (p = 0.049), while NF1 lost its unfavorable significance (p = 0.151). CONCLUSIONS: TERT is herein proven to confer poor prognosis in high grade gliomas, independent of IDH and MGMT. NF1 seems to also confer poor prognosis although our small numbers do not allow for firm conclusions.

A review of predictive, prognostic and diagnostic biomarkers for brain tumours: towards personalised and targeted cancer therapy

Background:

Brain tumours are relatively rare disease but present a large medical challenge as there is currently no method for early detection of the tumour and are typically not diagnosed until patients have progressed to symptomatic stage which significantly decreases chances of survival and also minimises treatment efficacy. However, if brain cancers can be diagnosed at early stages and also if clinicians have the potential to prospectively identify patients likely to respond to specific treatments, then there is a very high potential to increase patients’ treatment efficacy and survival. In recent years, there have been several investigations to identify biomarkers for brain cancer risk assessment, early detection and diagnosis, the likelihood of identifying which group of patients will benefit from a particular treatment and monitoring patient response to treatment.

Materials and methods:

This paper reports on a review of 21 current clinical and emerging biomarkers used in risk assessment, screening for early detection and diagnosis, and monitoring the response of treatment of brain cancers.

Conclusion:

Understanding biomarkers, molecular mechanisms and signalling pathways can potentially lead to personalised and targeted treatment via therapeutic targeting of specific genetic aberrant pathways which play key roles in malignant brain tumour formation. The future holds promising for the use of biomarker analysis as a major factor for personalised and targeted brain cancer treatment, since biomarkers have the potential to measure early disease detection and diagnosis, the risk of disease development and progression, improved patient stratification for various treatment paradigms, provide accurate information of patient response to a specific treatment and inform clinicians about the likely outcome of a brain cancer diagnosis independent of the treatment received.

Characteristics and prognostic factors of age-stratified high-grade intracranial glioma patients: A population-based analysis

We evaluated characteristics and different prognostic factors for survival in age-stratified high-grade glioma in a U.S. cohort. Eligible patients were identified in the Surveillance, Epidemiology, and End Results (SEER) registries and stratified into 3 age groups: 20-39 years old (1,043 patients), 40-59 years old (4,503 patients), and >60 years old (5,045 patients). Overall and cancer-related survival data were obtained. Cox models were built to analyze the outcomes and risk factors. It showed that race was a prognostic factor for survival in patients 40 to 59 years old and in patients ≥60 years old. Partial resection was associated with lower overall survival and cause-specific survival in all age groups (overall survival: 20-39 yr: HR = 6.41; 40-59 yr: HR = 4.84; >60 yr: HR = 5.06; cause-specific survival: 20-39 yr: HR = 5.87; 40-59 yr: HR = 4.01; >60 yr: HR = 3.36). The study highlights that, while some prognostic factors are universal, others are age-dependent. The effectiveness of treatment approaches differs for patients in different age groups. Results of this study may help to develop personalized treatment protocols for glioma patients of different ages.

Interrelationships between molecular subtype, anatomical location, and extent of resection in diffuse glioma: a systematic review and meta-analysis

Background

The introduction of the 2016 WHO Classification of Tumors of the Central Nervous System has resulted in tumor groupings with improved prognostic value for diffuse glioma patients. Molecular subtype, primarily based on IDH-mutational status and 1p/19q-status, is a strong predictor of survival. It is unclear to what extent this finding may be mediated by differences in anatomical location and surgical resectability among molecular subgroups. Our aim was to elucidate possible correlations between (1) molecular subtype and anatomical location and (2) molecular subtype and extent of resection.

Methods

We performed a systematic review of literature searching for studies on molecular subtype in relation to anatomical location and extent of resection. Only original data concerning adult participants suffering from cerebral diffuse glioma were included. Studies adopting similar outcomes measures were included in our meta-analysis.

Results

In the systematic analysis for research questions 1 and 2, totals of 20 and 9 studies were included, respectively. Study findings demonstrated that IDH-mutant tumors were significantly more frequently located in the frontal lobe and less often in the temporal lobe compared with IDH-wildtype gliomas. Within the IDH-mutant group, 1p/19q-codeleted tumors were associated with more frequent frontal and less frequent temporal localization compared with 1p/19q-intact tumors. In IDH-mutant gliomas, greater extent of resection was achieved than in IDH-wildtype tumors.

Conclusions

Genetic profile of diffuse cerebral glioma influences their anatomical location and seems to affect tumor resectability.

Expression of mucins (MUC1, MUC2, MUC5AC and MUC6) in ALK-positive lung cancer: Comparison with EGFR-mutated lung cancer

ALK-positive (ALK+) lung adenocarcinoma usually shows a more advanced-staged disease with frequent nodal metastasis and highly aggressive outcomes compared with EGFR-mutated lung cancers. The aim of this study was to investigate the expression profiles of several mucins in ALK + lung cancers to gain insight into the relationship between the more aggressive biological nature of ALK + lung cancers and the role of mucins. We examined the immunohistochemical profiles of mucins MUC1, MUC2, MUC5AC, and MUC6 in 19 ALK + lung cancers compared with 42 EGFR-mutated lung cancers. ALK + cancers were found to occur in younger patients and were characterized by a solid-predominant histologic subtype with frequent signet ring cells and peritumoral muciphages. By contrast, EGFR-mutated cancers lacked ALK-specific histological patterns. Although all MUC1 and MUC5AC were expressed in both subtypes, MUC1 expression in ALK + cancers was visualized exclusively through cytoplasmic staining, whereas those in EGFR-mutated cancers were predominantly membranous staining in apical area (92.9%) and focally in cytoplasmic staining (7.1%). MUC5AC expression in ALK + cancers was exclusively visualized through cytoplasmic staining (100%), whereas EGFR-mutated cancers showed predominantly perinuclear dot-like patterns (90.5%) and focal cytoplasmic staining (9.5%). MUC2 and MUC6 expression was not detected in either type of lung cancer. CONCLUSIONS: The high frequency of both MUC1 and MUC5AC cytoplasmic expression, coupled with a lack of MUC2 and MUC6 expression in ALK + lung cancer may contribute to the biologically aggressive behavior of ALK + cancer. Inhibitors to these types of mucins may thus act as a barrier to cancerous extension reducing their aggressive behavior.