CDKN2A deletion associated with poor prognosis in patients with TERT promoter wild-type, IDH wild-type glioblastoma

CDKN2A deletion associated with poor prognosis in patients with TERT promoter wild-type, IDH wild-type glioblastoma | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article CDKN2A deletion associated with poor prognosis in patients with TERT promoter wild-type, IDH wild-type glioblastoma Shigeru Kamimura, Yuta Mitobe, Kazuki Nakamura, Takanobu Kabasawa, and 3 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9350156/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Background The most common alterations in IDH wild-type primary glioblastoma (GBM) are mutations in the promoter region of the telomerase reverse transcriptase gene ( TERT p). This retrospective study investigated whether the impact of clinicopathological factors on prognosis in patients with GBM depends on TERT p status. Methods Among 112 cases of IDH wild-type GBM, 70 patients (62.5%) had the TERT p mutation. Clinical, immunohistochemical, and genetic factors (ATRX expression, and O 6 -methylguanine-DNA methyltransferase promoter [ MGMT p] methylation), and copy number alterations (CNAs) were investigated. Results Loss of ATRX, PDGFR amplification/gain, MDM2 amplification/gain, and TP53 hemizygous deletion were more frequent in patients with TERT p wild-type GBM ( P = 0.005, P = 0.009, P = 0.033, P = 0.009, respectively). EGFR amplification/gain and PTEN deletion were more frequent in those with TERT p mutant GBM (both P < 0.001). Postoperative residual tumor volume and MGMT p methylation were significantly correlated with PFS and OS in patients with TERT p mutant GBM. Only CDKN2A deletion was strongly correlated with poor OS in patients with TERT p wild-type GBM ( P < 0.001). Conclusions CDKN2A deletion alone was associated with the prognosis of TERT p wild-type GBM. Therefore, TERT p wild-type GBM may be a distinct clinical subtype of IDH wild-type GBM. glioblastoma TERT promoter MGMT promoter CDKN2A deletion Figures Figure 1 Figure 2 Figure 3 Introduction Glioblastoma (GBM) is the most common primary malignant tumor of the central nervous system in adults [ 1 ]. Despite radical surgery plus concomitant temozolomide-based chemoradiation therapy, patients have a median survival of approximately 18 months [ 2 ]. There are many known prognostic factors for GBM, which can be classified as patient factors (i.e., age, gender, and preoperative KPS), treatment factors (i.e., degree of surgical resection and presence of adjuvant treatment), and molecular biological factors (i.e., methylation of the O6-methylguanine-DNA methyltransferase promoter [ MGMT p], EGFR amplification, and PTEN deletion) [ 3 – 5 ]. Mutations in the promoter region of the telomerase reverse transcriptase ( TERT p) gene are most frequently found in GBM, but their prognostic significance remains unclear [ 6 – 9 ]. Several recent reports have shown that MGMT p methylation, which is a prognostic factor for GBM, did not have prognostic significance in TERT p wild-type GBM [ 10 , 11 ]. In contrast, CDKN2A homozygous deletion was reported to be a poor prognostic factor in IDH -mutant gliomas, but the prognostic significance of CDKN2A deletion in IDH wild-type GBM remains unclear [ 12 , 13 ]. This study analyzed the relationship between TERT p status with other clinical and molecular factors, specifically MGMT p and CDKN2A status, in patients with GBM. Materials and methods Patients and samples This retrospective study was conducted with the approval of the Ethics Committees of the Yamagata University School of Medicine. Written informed consent was provided by all patients prior to their participation in the study. Between January 2014 and October 2024, a total of 112 patients were enrolled in this study. The inclusion criteria were as follows: 1) diagnosis of IDH wild-type GBM according to the World Health Organization classification of central nervous system tumors (WHO CNS) 5th edition; 2) no history of lower-grade tumors; 3) availability of genomic DNA; and 4) available outcome data (i.e., recurrence or death during follow-up) or absence of such events for ≥ 12 months of follow-up. Patients with previous biopsies were excluded from the study. Tumor specimens were obtained from lesions that exhibited enhancement on gadolinium-enhanced MRI and were immediately stored at − 80°C until DNA extraction. Volumetric image analysis Magnetic resonance imaging (MRI) sequences were acquired on a 1.5-T or 3.0-T scanner and typically included axial T1-weighted, T2-weighted fast spin-echo, and fluid-attenuated inversion-recovery sequences, as well as a post-contrast three-dimensional spoiled gradient-recalled acquisition in the steady state T1-weighted sequence. Pre- and postoperative MRI (obtained ≤ 72 h after surgery) were used to quantify tumor volumes, which were delineated using preferred institutional software (BrainLab Smartbrush). The total contrast-enhanced (CE) tumor volume was measured on contrast-enhanced T1-weighted sequences, while the non-CE (nCE) tumor volume (i.e., signal alterations beyond the enhancing tumor borders) was measured on FLAIR sequences. The extent of resection was evaluated according to the classification system proposed by the RANO resect group [ 14 ], described as follows: Class 1: supramaximal resection of the CE tumor (0 cm 3 CE + ≤ 5 cm 3 nCE) Class 2A: maximal CE resection (complete CE resection) (0 cm 3 CE + > 5 cm 3 nCE) Class 2B: maximal CE resection (near-total CE resection) (≤ 1 cm 3 CE) Class 3A: submaximal resection (subtotal CE resection) (≤ 5 cm 3 CE) Class 3B: submaximal resection (partial CE resection) (> 5 cm 3 .CE) Class 4: biopsy (no reduction of tumor volume) Clinical parameters The patients’ clinical profiles were obtained from the medical records. All patients underwent radical surgery followed by temozolomide and radiotherapy. If the primary tumor recurred, patients underwent salvage surgery, second-line chemotherapy, radiotherapy, or palliative therapy. Prognosis Progression-free survival (PFS) was defined as the time between the date of first surgery and the detection of recurrence on MRI. Overall survival (OS) was defined as the time between the date of the first operation until death or final follow-up. Molecular analysis Genomic DNA was extracted using the QIAamp DNA mini kit (Qiagen) as per the manufacturer’s instructions. The isocitrate dehydrogenase1 ( IDH1 ), H3.3 histone A ( H3F3A ), BRAF , and TERTp genes were amplified via polymerase chain reaction (PCR), and sequencing was conducted as previously described [ 15 , 16 ]. In the MGMT promoter methylation analysis, quantitative methylation-specific PCR was performed following the bisulfite modification of tumor DNA [ 17 ]. To assess copy number alteration (CNA)s, multiplex ligation-dependent probe amplification (MLPA) was performed using the SALSA MLPA KIT P105 (version D2) following the manufacturer’s protocol (MRC Holland, Amsterdam, Netherlands). The P105 kit is designed to detect CNAs typical in gliomas, including probes against PDGFRA, EGFR, CDKN2A, PTEN , and CDK4. Each category was classified by the following thresholds: homozygous deletion (x ≤ 0.4), hemizygous deletion (0.4 < x ≤ 0.7), gain (1.3 ≤ x < 2.0), amplification (x ≥ 2.0) [ 17 – 19 ]. The CNAs in 89 patients were described previously [ 19 ]. The OncoPrinter, a tool provided by the cBioPortal for Cancer Genomics (cbioportal.org/oncoprinter), was used to visualize and analyze the data with some modifications [ 20 , 21 ]. Immunohistochemistry Immunohistochemistry was conducted on 4-µm formalin-fixed, paraffin-embedded tissue sections. The sections were immunostained using an anti-human ATRX antibody (Abcam) or an anti-human Ki-67 protein antibody (Dako). ATRX loss was defined as the absence of staining in more than 90% of tumor cells [ 22 ]. The Ki67 labeling index was determined as described previously [ 23 ]. Statistical analysis Statistical analyses were performed using SPSS (IBM Japan, Tokyo, Japan) software. The relationship between two variables was evaluated using the Mann–Whitney U test and Fisher’s exact test. Estimates of PFS and OS were calculated using the Kaplan–Meier method. The log-rank (Mantel–Cox) test was used to evaluate differences between groups. Cox regression was used for multivariate analysis. Statistical significance was set at P < 0.05. Results Population and tumor characteristics on MRI The study cohort included 112 patients (60 males, 52 females) with a median age of 66 years (range: 29–89) and a median preoperative Karnofsky Performance Status of 80 (range: 20–100) (Table 1). Genomic DNA was obtained from all patients. The median follow-up duration was 18 months (range: 4–124 months), and 88 patients (78.5%) died. Patients were stratified using the classification system proposed by the RANO resect group, as follows: class 1 (2/112 patients, 1.8%), class 2A (49/112 patients, 43.8%), class 2B (27/112 patients, 24.1%), class 3A (20/112 patients, 17.9%), and class 3B (14/112 patients, 12.5%). Regarding genetic mutations, no IDH1 or H3F3A gene mutations were detected in this cohort. TERT p gene mutations were detected in 70 patients (62.5%), among whom 52 (74.3%) and 18 (25.7%) patients had C228T and C250T mutations, respectively. Loss of ATRX was found in 21 patients (18.8%). MGMT gene promoter methylation was found in 53 patients (47.3%). Figure 1 and Table 1 also describe other specific mutations, such as PDGFR amp/gain (n = 20, 17.8%), EGFR amp/gain (n = 69, 61.6%), CDKN2A (n = 75, 70.0%) deletion, PTEN deletion (n = 48, 42.9%), CDK4 amp/gain (n = 18, 16.1%), MDM2 amp/gain (n = 18, 16.1%), NFKBIA deletion (n = 18, 16.1%), and TP53 hemizygous deletion (n = 10, 10.7%). Regarding postoperative treatments, all patients received combined radiation and chemotherapy with temozolomide. Bevacizumab was administered as a second-line therapy in 67 patients. Tumor-treating therapy was administered in 6 patients after radiation. Correlation analyses between the TERT p status and other prognostic factors The preoperative KPS was higher in patients with TERT p mutant versus TERT p wild-type GBM ( P = 0.009) (Table 1). Loss of ATRX, PDGFR amplification/gain, MDM2 amplification/gain, and TP53 hemizygous deletion were more frequent in TERT p wild-type GBM ( P = 0.005, P = 0.009, P = 0.033, P = 0.009, respectively), whereas EGFR amplification/gain and PTEN deletion were more frequent in TERT p mutant GBM (both P < 0.001) (Table 1). No correlations were observed for other factors (Table 1). Univariate analysis for the prediction of PFS and OS Patients with IDH wild-type GBM had a median PFS of 7 months and a median OS of 20 months (Table 2). Based on the Kaplan–Meier analysis, longer PFS and OS correlated with RANO class 1/2A (complete resection of the CE tumor) ( P = 0.025 and P = 0.012, respectively) (Supplementary Fig. 1A and B). CDKN2A deletion was correlated with OS ( P = 0.015) (Supplementary Fig. 1C and D). Among patients with TERT p mutant GBM, there were significant differences in PFS ( P = 0.012) and OS ( P = 0.003) between RANO class 1/2A versus RANO class 2B/3 (Fig. 2 A and B, Table 3). Moreover, MGMT p methylation was significantly correlated with PFS and OS ( P = 0.010 and P = 0.010, respectively) (Fig. 2 C and D, Table 3), whereas CDKN2 A deletion had no correlation with either (Fig. 2 E and F, Table 3). Among patients with TERT p wild-type GBM, there were no significant differences in PFS and OS among RANO class 1/2A versus RANO class 2B/3 ( P = 0.265 and P = 0.391, respectively) (Fig. 3 A and B, Table 3) and among patients with versus without MGMT p methylation ( P = 0.906 and P = 0.371, respectively) (Fig. 3 C and D, Table 3). CDKN2A deletion was strongly correlated with poor OS ( P < 0.001) (Fig. 3 E and F, Table 3). Multivariate analysis of prognostic factors The multivariate analysis for PFS and OS included the following factors: age, extent of resection (RANO class), MGMT gene promoter methylation, and CDKN2A deletion (Supplementary Table 1). The absence of total CE tumor resection (RANO class 1/2A) was an independent predictor of unfavorable prognosis in terms of both PFS (hazard ratio [HR]: 1.6, 95% confidence interval [CI]: 1.1–2.4, P = 0.024) and OS (HR: 1.9, 95% CI: 1.2–2.7, P = 0.008). Meanwhile, CDKN2A deletion independently predicted poor OS (HR: 1.3, 95% CI: 1.1–3.0, P < 0.001). Among patients with TERT p wild-type GBM, CDKN2A deletion was the sole factor that independently predicted poor OS (HR: 5.0, 95% CI: 1.8–13.6, P = 0.002) (Supplementary Table 2). Discussion The TERT p mutation has been found in approximately 70%–80% of patients with IDH wild-type GBM [ 6 , 7 ]. In our previous report, only 50%–70% of Japanese patients with IDH wild-type GBM were found to have the TERT p mutation. The frequency of TERT p mutation (62.5%) found in the present study is in line with previous reports from Japan [ 18 , 24 ]. Aside from TERT p mutations, ATRX or SMARCAL 1 gene mutations are also known mechanisms of tumor cell immortalization [ 25 ]. In fact, ATRX loss is more common in patients with TERT p wild-type GBM. However, since the frequency of ATRX loss was not very high, other immortalization mechanisms are likely involved as well. Furthermore, unlike in IDH- mutant gliomas, TERT p mutation and loss of ATRX expression are not mutually exclusive. Since it may be somewhat difficult to interpret the loss of ATRX expression on immunohistochemistry, ATRX mutation analysis may be necessary in the future. The clinical and prognostic impacts of TERT p mutation remain controversial in patients with GBM. In other cancers, several studies have demonstrated its correlations with poor prognosis, aggressive clinicopathological characteristics, and metastasis [ 26 , 27 ]. In our previous report, TERT p mutation was significantly associated with shortened PFS and OS on univariate and multivariate analyses [ 19 ]. However, in this cohort, patients with TERT p mutations tended to have shorter OS than patients without mutations, although the difference was not statistically significant. Thus, the prognostic significance of TERT p mutations will require further investigation in a larger number of cases. In a previous study, prognosis remained similar regardless of the presence of MGMT p methylation, despite it being a well-known prognostic factor for GBM [ 4 ]. Similarly, several studies have shown that MGMT p status has little prognostic impact among cases of TERT p wild-type GBM [ 10 , 11 , 19 ]. In fact, in our study, MGMT p methylation was a favorable prognostic factor for both PFS and OS in TERT p mutant GBM. In IDH -mutant astrocytoma, homozygous CDKN2A deletion is associated with poor prognosis; such cases are classified as WHO CNS grade 4. However, the prognostic impact of CDKN2A deletion remains unclear in GBM [ 12 , 13 ]. One recent report demonstrated that TERTp mutations and CDKN2A deletions occur in the early stage of GBM development [ 28 ]. Thus, the mechanism of development of TERT p wild-type GBM may be completely different from that of TERT p mutant GBM. In the present analysis, CDKN2A deletion did not affect prognosis in TERT p mutant GBM, but it was a statistically significant factor for poor prognosis in TERT p wild-type cases. Thus, the development of TERT p wild-type GBM may follow a similar mechanism as IDH -mutant astrocytoma. The limitations of the present study must be acknowledged. First, this was a retrospective study with a small sample size. Second, it remains unclear why MGMT p methylation was not identified as a prognostic factor. Lastly, the mechanism of temozolomide resistance in TERT p wild-type GBM warrants further investigation. Conclusion This retrospective study investigated whether TERT p status influences the prognostic impact of certain clinicopathological factors in patients with GBM. CDKN2A deletion was strongly associated with PFS and OS in TERT p wild-type GBM. Abbreviations CE contrast-enhanced GBM glioblastoma H3F3A H3.3 histone A IDH isocitrate dehydrogenase IDH1 isocitrate dehydrogenase 1 MGMT O 6 -methylguanine-DNA methyltransferase MRI magnetic resonance imaging OS overall survival PCR polymerase chain reaction PFS progression-free survival TERT p promoter region of telomerase reverse transcriptase Declarations Acknowledgments The authors thank Enago (https://www.enago.jp/)for the English-language review. Author contributions SK, YS: conception and design of the work. SK, YM, KN, KS, TK: data curation and writing of the original draft. YS: funding acquisition. MF, YK: writing, review, and editing. Funding This work was supported by JSPS KAKENHI (Grant Number 23K08493 and 26K12030). Conflict of interest : All authors declare that they have no conflicts of interest. Ethical approval: Thisstudy was approved by the Ethics Committee of Yamagata University Hospital (approval number: 2018-498). 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Sci Signal 6:pl1 Cerami E, Gao J, Dogrusoz U et al (2012) The cBio cancer genomics portal: an open platform for exploring multidimensional cancer genomics data. Cancer Discov 2:401–404 Wiestler B, Capper D, Holland-Letz T et al (2013) ATRX loss refines glioma classification. Acta Neuropathol 126:443–451 Takano S, Kato Y, Yamamoto T et al (2016) Ki-67 labeling index in gliomas. Brain Tumor Pathol 33:83–88 Arita H, Narita Y, Fukushima S et al (2013) TERT promoter mutations in gliomas. Acta Neuropathol 126:267–276 Diplas BH, He X, Brosnan-Cashman JA et al (2018) Genomic landscape of TERT wild-type glioblastoma. Nat Commun 9:2087 Yuan P, Cao JL, Abuduwufuer A et al (2016) TERT promoter mutations in cancer: meta-analysis. PLoS ONE 11:e0146803 Campos MA, Macedo S, Fernandes M et al (2019) TERT promoter mutations and prognosis in carcinoma. J Am Acad Dermatol 80:660–669 Barthel FP, Johnson KC, Varn FS et al (2019) Molecular trajectories of diffuse glioma. Nature 576:112–120 Tables Tables 1 to 3 are available in the Supplementary Files section. Supplementary Files SippleFigure1.tif Supplementary Fig.1 Kaplan–Meier survival curves according to RANO classification in all patients. (A, B) Kaplan–Meier curves for PFS and OS according to RANO classification (class 1/2A vs. 2B/3). (C, D) Kaplan–Meier curves for PFS and OS according to CDKN2A status (deleted vs. intact). Survival was better in the RANO class 1/2A than in the RANO class 2B/3 subgroup. CDKN2A deletion was associated with worse survival. Abbreviations: PFS, progression-free survival; OS, overall survival. Table10401.xlsx Table20401.xlsx Table30401.xlsx Suppl.Table10401.xlsx SupplTable2.0401.xlsx Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 30 Apr, 2026 Reviewers invited by journal 30 Apr, 2026 Editor assigned by journal 15 Apr, 2026 First submitted to journal 07 Apr, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9350156","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":632668820,"identity":"663d054c-0700-403b-8134-5bcd6b40dc0c","order_by":0,"name":"Shigeru Kamimura","email":"","orcid":"","institution":"Yamagata Daigaku","correspondingAuthor":false,"prefix":"","firstName":"Shigeru","middleName":"","lastName":"Kamimura","suffix":""},{"id":632668821,"identity":"d4460281-1346-4409-b936-c5048836966d","order_by":1,"name":"Yuta Mitobe","email":"","orcid":"","institution":"Yamagata Daigaku Igakubu Daigakuin Igakukei Kenkyuka","correspondingAuthor":false,"prefix":"","firstName":"Yuta","middleName":"","lastName":"Mitobe","suffix":""},{"id":632668822,"identity":"737cec89-2afa-40e9-97ac-6fe9240705a0","order_by":2,"name":"Kazuki Nakamura","email":"","orcid":"","institution":"Yamagata University Faculty of Medicine: Yamagata Daigaku Igakubu Daigakuin Igakukei Kenkyuka","correspondingAuthor":false,"prefix":"","firstName":"Kazuki","middleName":"","lastName":"Nakamura","suffix":""},{"id":632668823,"identity":"fdb8a26a-e775-4cb6-9479-a417122eecd9","order_by":3,"name":"Takanobu Kabasawa","email":"","orcid":"","institution":"Yamagata University Faculty of Medicine: Yamagata Daigaku Igakubu Daigakuin Igakukei Kenkyuka","correspondingAuthor":false,"prefix":"","firstName":"Takanobu","middleName":"","lastName":"Kabasawa","suffix":""},{"id":632668824,"identity":"65a1aa5c-9348-4b60-8584-4aa5f674fd76","order_by":4,"name":"Mitsuru Futakuchi","email":"","orcid":"","institution":"Yamagata University Faculty of Medicine: Yamagata Daigaku Igakubu Daigakuin Igakukei Kenkyuka","correspondingAuthor":false,"prefix":"","firstName":"Mitsuru","middleName":"","lastName":"Futakuchi","suffix":""},{"id":632668825,"identity":"717f3145-47bd-4b9e-bca7-59f02273bbd0","order_by":5,"name":"Yonehiro Kanemura","email":"","orcid":"","institution":"National Hospital Organization Osaka National Hospital: Kokuritsu Byoin Kiko Osaka Iryo Center","correspondingAuthor":false,"prefix":"","firstName":"Yonehiro","middleName":"","lastName":"Kanemura","suffix":""},{"id":632668826,"identity":"cbd1c5e3-40f3-4d28-a09a-eb41f1c97d48","order_by":6,"name":"Yukihiko Sonoda","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABQ0lEQVRIiWNgGAWjYNACNgY5IGnAkMCGIcWDU4sxmpYEwloSG0BaGDC1YAKD84ePPfhQZpe+tr15A8ODMobE/mmHH7/4+cOOweAA88MPDDJ3MLTcSEs3nHEuOXfbmWMFDAnnGBJn3E4zs+xJSAZqYTOWYOB5hqmFx0yat405d9uNHAOGxDagC28nmBnwJDDXbzjAYAb0y2FMh50BaalPN7v/BqJl/u30b4Z/EuqBtrB/w6rlQA5Iy+EEsxs8EC0bbucYP+ZJOAyU4sFqi+SNtDTJGeeOG247k1ZwIOGchPHG2zllzDJpxxkkD/MUSyRg+oUPGGISH8qq5c2OH9748EeZjey82+mbP76xqWbgO96+8cPHHowQUziAxAGyJRwbgLEjAeYyA3FizwF0LfINaAL2ILUfEPwfGFpGwSgYBaNgxAEA9HZ2YABjLs4AAAAASUVORK5CYII=","orcid":"https://orcid.org/0000-0001-7651-1374","institution":"Yamagata Daigaku Igakubu Daigakuin Igakukei Kenkyuka","correspondingAuthor":true,"prefix":"","firstName":"Yukihiko","middleName":"","lastName":"Sonoda","suffix":""}],"badges":[],"createdAt":"2026-04-08 01:30:11","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9350156/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9350156/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":108978791,"identity":"7318e6af-d4d0-467b-a67e-42a7e77e52d3","added_by":"auto","created_at":"2026-05-11 11:48:30","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":116551,"visible":true,"origin":"","legend":"\u003cp\u003eGenetic distribution of mutations across 112 cases of glioblastoma. IHC, Mutations, CNAs, and methylation were generated and visualized by OncoPrinter via the cBioPortal for Cancer Genomics (cbioportal.org/oncoprinter) with some modifications [20,21]. The diagram shows the landscape of the molecular characteristics of GBMs, which are sorted by \u003cem\u003eTERT\u003c/em\u003ep mutations and CDKN2A deletion. Abbreviations: IHC, immunohistochemistry; CNA, copy number alteration; GBM, glioblastoma; N/A, not available.\u003c/p\u003e","description":"","filename":"Figure1.png","url":"https://assets-eu.researchsquare.com/files/rs-9350156/v1/f979c74264638a911a992604.png"},{"id":108978818,"identity":"1d3170ed-793e-4c60-a880-a6a436fa1857","added_by":"auto","created_at":"2026-05-11 11:49:08","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":93832,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eKaplan–Meier survival curves in TERT promoter–mutant glioblastoma.\u003cbr\u003e\n \u003c/strong\u003e(A, B) Kaplan–Meier curves for PFS and OS according to the RANO classification (class 1/2A vs. 2B/3).\u003cbr\u003e\n(C, D) Kaplan–Meier curves for PFS and OS according to MGMT promoter methylation status (methylated vs. unmethylated).\u003cbr\u003e\n(E, F) Kaplan–Meier curves for PFS and OS according to CDKN2A status (deleted vs. intact).\u003cbr\u003e\nIn the TERT promoter–mutant subgroup, RANO classification and MGMT promoter methylation were significantly associated with survival, whereas CDKN2A status was not. Abbreviations: PFS, progression-free survival; OS, overall survival.\u003c/p\u003e","description":"","filename":"Figure2.png","url":"https://assets-eu.researchsquare.com/files/rs-9350156/v1/be49c6c800ab1e61bba55c70.png"},{"id":108978738,"identity":"2ba7246d-d089-432a-a190-bcc1e50dd801","added_by":"auto","created_at":"2026-05-11 11:48:17","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":90098,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eKaplan–Meier survival curves in TERT promoter–wild-type glioblastoma.\u003cbr\u003e\n \u003c/strong\u003e(A, B) Kaplan–Meier curves for PFS and OS according to RANO classification (class 1/2A vs. 2B/3).\u003cbr\u003e\n(C, D) Kaplan–Meier curves for PFS and OS according to MGMT promoter methylation status (methylated vs. unmethylated).\u003cbr\u003e\n(E, F) Kaplan–Meier curves for PFS and OS according to CDKN2A status (deleted vs. intact).\u003cbr\u003e\nIn the TERT promoter–wild-type subgroup, CDKN2A deletion was significantly associated with worse OS. RANO classification and MGMT promoter methylation were not significantly associated with survival.\u003c/p\u003e\n\u003cp\u003eAbbreviations: PFS, progression-free survival; OS, overall survival.\u003c/p\u003e","description":"","filename":"Figure3.png","url":"https://assets-eu.researchsquare.com/files/rs-9350156/v1/153aa62dcac5d0b95eb60955.png"},{"id":108981061,"identity":"371be636-db70-4fc9-b811-7d56299bd835","added_by":"auto","created_at":"2026-05-11 12:13:38","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":553501,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9350156/v1/9559582b-31d1-4df8-9cac-5df8c56ee87a.pdf"},{"id":108978819,"identity":"f2cf4542-7231-4517-ad7b-775fe75b24cc","added_by":"auto","created_at":"2026-05-11 11:49:08","extension":"tif","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":164244,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary Fig.1 Kaplan–Meier survival curves according to RANO classification in all patients.\u003c/p\u003e\n\u003cp\u003e(A, B) Kaplan–Meier curves for PFS and OS according to RANO classification (class 1/2A vs. 2B/3).\u003c/p\u003e\n\u003cp\u003e(C, D) Kaplan–Meier curves for PFS and OS according to CDKN2A status (deleted vs. intact).\u003c/p\u003e\n\u003cp\u003eSurvival was better in the RANO class 1/2A than in the RANO class 2B/3 subgroup. CDKN2A deletion was associated with worse survival.\u003c/p\u003e\n\u003cp\u003eAbbreviations: PFS, progression-free survival; OS, overall survival.\u003c/p\u003e","description":"","filename":"SippleFigure1.tif","url":"https://assets-eu.researchsquare.com/files/rs-9350156/v1/6dd9b185ee60badf0e03af86.tif"},{"id":108978820,"identity":"163ff693-a8e2-4a49-a378-7e403dae860e","added_by":"auto","created_at":"2026-05-11 11:49:08","extension":"xlsx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":13444,"visible":true,"origin":"","legend":"","description":"","filename":"Table10401.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-9350156/v1/48bc26f21f004d91d5ba31e2.xlsx"},{"id":108978739,"identity":"7703ec87-e15f-4c13-8220-a396ec380e0e","added_by":"auto","created_at":"2026-05-11 11:48:17","extension":"xlsx","order_by":3,"title":"","display":"","copyAsset":false,"role":"supplement","size":14350,"visible":true,"origin":"","legend":"","description":"","filename":"Table20401.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-9350156/v1/9a03dc7aed2150ac8759ea79.xlsx"},{"id":108978821,"identity":"0dba11d6-3abf-410b-917e-0f3cca1e88b8","added_by":"auto","created_at":"2026-05-11 11:49:08","extension":"xlsx","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":15540,"visible":true,"origin":"","legend":"","description":"","filename":"Table30401.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-9350156/v1/67d00cd8449c72c84b49b8f4.xlsx"},{"id":108978736,"identity":"080932b5-b9a7-4668-8d96-95c607d179da","added_by":"auto","created_at":"2026-05-11 11:48:15","extension":"xlsx","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":12504,"visible":true,"origin":"","legend":"","description":"","filename":"Suppl.Table10401.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-9350156/v1/6817a903c98ab9b0339d6483.xlsx"},{"id":108978814,"identity":"3264e617-5104-483e-9aaa-ef67806cb021","added_by":"auto","created_at":"2026-05-11 11:48:52","extension":"xlsx","order_by":6,"title":"","display":"","copyAsset":false,"role":"supplement","size":13054,"visible":true,"origin":"","legend":"","description":"","filename":"SupplTable2.0401.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-9350156/v1/dfa84054aa173edd168c0df0.xlsx"}],"financialInterests":"","formattedTitle":"CDKN2A deletion associated with poor prognosis in patients with TERT promoter wild-type, IDH wild-type glioblastoma","fulltext":[{"header":"Introduction","content":"\u003cp\u003eGlioblastoma (GBM) is the most common primary malignant tumor of the central nervous system in adults [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Despite radical surgery plus concomitant temozolomide-based chemoradiation therapy, patients have a median survival of approximately 18 months [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. There are many known prognostic factors for GBM, which can be classified as patient factors (i.e., age, gender, and preoperative KPS), treatment factors (i.e., degree of surgical resection and presence of adjuvant treatment), and molecular biological factors (i.e., methylation of the O6-methylguanine-DNA methyltransferase promoter [\u003cem\u003eMGMT\u003c/em\u003ep], \u003cem\u003eEGFR\u003c/em\u003e amplification, and \u003cem\u003ePTEN\u003c/em\u003e deletion) [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMutations in the promoter region of the telomerase reverse transcriptase (\u003cem\u003eTERT\u003c/em\u003ep) gene are most frequently found in GBM, but their prognostic significance remains unclear [\u003cspan additionalcitationids=\"CR7 CR8\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Several recent reports have shown that \u003cem\u003eMGMT\u003c/em\u003ep methylation, which is a prognostic factor for GBM, did not have prognostic significance in \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. In contrast, \u003cem\u003eCDKN2A\u003c/em\u003e homozygous deletion was reported to be a poor prognostic factor in \u003cem\u003eIDH\u003c/em\u003e-mutant gliomas, but the prognostic significance of \u003cem\u003eCDKN2A\u003c/em\u003e deletion in \u003cem\u003eIDH\u003c/em\u003e wild-type GBM remains unclear [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis study analyzed the relationship between \u003cem\u003eTERT\u003c/em\u003ep status with other clinical and molecular factors, specifically \u003cem\u003eMGMT\u003c/em\u003ep and \u003cem\u003eCDKN2A\u003c/em\u003e status, in patients with GBM.\u003c/p\u003e"},{"header":"Materials and methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003ePatients and samples\u003c/h2\u003e \u003cp\u003e This retrospective study was conducted with the approval of the Ethics Committees of the Yamagata University School of Medicine. Written informed consent was provided by all patients prior to their participation in the study.\u003c/p\u003e \u003cp\u003eBetween January 2014 and October 2024, a total of 112 patients were enrolled in this study. The inclusion criteria were as follows: 1) diagnosis of \u003cem\u003eIDH\u003c/em\u003e wild-type GBM according to the World Health Organization classification of central nervous system tumors (WHO CNS) 5th edition; 2) no history of lower-grade tumors; 3) availability of genomic DNA; and 4) available outcome data (i.e., recurrence or death during follow-up) or absence of such events for \u0026ge;\u0026thinsp;12 months of follow-up. Patients with previous biopsies were excluded from the study. Tumor specimens were obtained from lesions that exhibited enhancement on gadolinium-enhanced MRI and were immediately stored at \u0026minus;\u0026thinsp;80\u0026deg;C until DNA extraction.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eVolumetric image analysis\u003c/h3\u003e\n\u003cp\u003eMagnetic resonance imaging (MRI) sequences were acquired on a 1.5-T or 3.0-T scanner and typically included axial T1-weighted, T2-weighted fast spin-echo, and fluid-attenuated inversion-recovery sequences, as well as a post-contrast three-dimensional spoiled gradient-recalled acquisition in the steady state T1-weighted sequence. Pre- and postoperative MRI (obtained\u0026thinsp;\u0026le;\u0026thinsp;72 h after surgery) were used to quantify tumor volumes, which were delineated using preferred institutional software (BrainLab Smartbrush). The total contrast-enhanced (CE) tumor volume was measured on contrast-enhanced T1-weighted sequences, while the non-CE (nCE) tumor volume (i.e., signal alterations beyond the enhancing tumor borders) was measured on FLAIR sequences. The extent of resection was evaluated according to the classification system proposed by the \u003cem\u003eRANO\u003c/em\u003e resect group [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], described as follows:\u003c/p\u003e \u003cp\u003eClass 1: supramaximal resection of the CE tumor (0 cm\u003csup\u003e3\u003c/sup\u003e CE\u0026thinsp;+\u0026thinsp;\u0026le;\u0026thinsp;5 cm\u003csup\u003e3\u003c/sup\u003e nCE)\u003c/p\u003e \u003cp\u003eClass 2A: maximal CE resection (complete CE resection) (0 cm\u003csup\u003e3\u003c/sup\u003e CE\u0026thinsp;+\u0026thinsp;\u0026gt;\u0026thinsp;5 cm\u003csup\u003e3\u003c/sup\u003e nCE)\u003c/p\u003e \u003cp\u003eClass 2B: maximal CE resection (near-total CE resection) (\u0026le;\u0026thinsp;1 cm\u003csup\u003e3\u003c/sup\u003e CE)\u003c/p\u003e \u003cp\u003eClass 3A: submaximal resection (subtotal CE resection) (\u0026le;\u0026thinsp;5 cm\u003csup\u003e3\u003c/sup\u003e CE)\u003c/p\u003e \u003cp\u003eClass 3B: submaximal resection (partial CE resection) (\u0026gt;\u0026thinsp;5 cm\u003csup\u003e3\u003c/sup\u003e.CE)\u003c/p\u003e \u003cp\u003eClass 4: biopsy (no reduction of tumor volume)\u003c/p\u003e\n\u003ch3\u003eClinical parameters\u003c/h3\u003e\n\u003cp\u003eThe patients\u0026rsquo; clinical profiles were obtained from the medical records. All patients underwent radical surgery followed by temozolomide and radiotherapy. If the primary tumor recurred, patients underwent salvage surgery, second-line chemotherapy, radiotherapy, or palliative therapy.\u003c/p\u003e\n\u003ch3\u003ePrognosis\u003c/h3\u003e\n\u003cp\u003eProgression-free survival (PFS) was defined as the time between the date of first surgery and the detection of recurrence on MRI. Overall survival (OS) was defined as the time between the date of the first operation until death or final follow-up.\u003c/p\u003e\n\u003ch3\u003eMolecular analysis\u003c/h3\u003e\n\u003cp\u003eGenomic DNA was extracted using the QIAamp DNA mini kit (Qiagen) as per the manufacturer\u0026rsquo;s instructions. The isocitrate dehydrogenase1 (\u003cem\u003eIDH1\u003c/em\u003e), H3.3 histone A (\u003cem\u003eH3F3A\u003c/em\u003e), \u003cem\u003eBRAF\u003c/em\u003e, and \u003cem\u003eTERTp\u003c/em\u003e genes were amplified via polymerase chain reaction (PCR), and sequencing was conducted as previously described [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. In the \u003cem\u003eMGMT\u003c/em\u003e promoter methylation analysis, quantitative methylation-specific PCR was performed following the bisulfite modification of tumor DNA [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. To assess copy number alteration (CNA)s, multiplex ligation-dependent probe amplification (MLPA) was performed using the SALSA MLPA KIT P105 (version D2) following the manufacturer\u0026rsquo;s protocol (MRC Holland, Amsterdam, Netherlands). The P105 kit is designed to detect CNAs typical in gliomas, including probes against \u003cem\u003ePDGFRA, EGFR, CDKN2A, PTEN\u003c/em\u003e, and \u003cem\u003eCDK4.\u003c/em\u003e Each category was classified by the following thresholds: homozygous deletion (x\u0026thinsp;\u0026le;\u0026thinsp;0.4), hemizygous deletion (0.4\u0026thinsp;\u0026lt;\u0026thinsp;x\u0026thinsp;\u0026le;\u0026thinsp;0.7), gain (1.3\u0026thinsp;\u0026le;\u0026thinsp;x\u0026thinsp;\u0026lt;\u0026thinsp;2.0), amplification (x\u0026thinsp;\u0026ge;\u0026thinsp;2.0) [\u003cspan additionalcitationids=\"CR18\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The CNAs in 89 patients were described previously [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. The OncoPrinter, a tool provided by the cBioPortal for Cancer Genomics (cbioportal.org/oncoprinter), was used to visualize and analyze the data with some modifications [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e].\u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eImmunohistochemistry\u003c/h2\u003e \u003cp\u003eImmunohistochemistry was conducted on 4-\u0026micro;m formalin-fixed, paraffin-embedded tissue sections. The sections were immunostained using an anti-human ATRX antibody (Abcam) or an anti-human Ki-67 protein antibody (Dako). ATRX loss was defined as the absence of staining in more than 90% of tumor cells [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. The Ki67 labeling index was determined as described previously [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eStatistical analysis\u003c/h2\u003e \u003cp\u003eStatistical analyses were performed using SPSS (IBM Japan, Tokyo, Japan) software. The relationship between two variables was evaluated using the Mann\u0026ndash;Whitney U test and Fisher\u0026rsquo;s exact test. Estimates of PFS and OS were calculated using the Kaplan\u0026ndash;Meier method. The log-rank (Mantel\u0026ndash;Cox) test was used to evaluate differences between groups. Cox regression was used for multivariate analysis. Statistical significance was set at \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.05.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003ePopulation and tumor characteristics on MRI\u003c/h2\u003e \u003cp\u003eThe study cohort included 112 patients (60 males, 52 females) with a median age of 66 years (range: 29\u0026ndash;89) and a median preoperative Karnofsky Performance Status of 80 (range: 20\u0026ndash;100) (Table\u0026nbsp;1). Genomic DNA was obtained from all patients. The median follow-up duration was 18 months (range: 4\u0026ndash;124 months), and 88 patients (78.5%) died. Patients were stratified using the classification system proposed by the \u003cem\u003eRANO\u003c/em\u003e resect group, as follows: class 1 (2/112 patients, 1.8%), class 2A (49/112 patients, 43.8%), class 2B (27/112 patients, 24.1%), class 3A (20/112 patients, 17.9%), and class 3B (14/112 patients, 12.5%).\u003c/p\u003e \u003cp\u003eRegarding genetic mutations, no \u003cem\u003eIDH1\u003c/em\u003e or \u003cem\u003eH3F3A\u003c/em\u003e gene mutations were detected in this cohort. \u003cem\u003eTERT\u003c/em\u003ep gene mutations were detected in 70 patients (62.5%), among whom 52 (74.3%) and 18 (25.7%) patients had C228T and C250T mutations, respectively. Loss of ATRX was found in 21 patients (18.8%). \u003cem\u003eMGMT\u003c/em\u003e gene promoter methylation was found in 53 patients (47.3%). Figure\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e and Table\u0026nbsp;1 also describe other specific mutations, such as \u003cem\u003ePDGFR\u003c/em\u003e amp/gain (n\u0026thinsp;=\u0026thinsp;20, 17.8%), \u003cem\u003eEGFR\u003c/em\u003e amp/gain (n\u0026thinsp;=\u0026thinsp;69, 61.6%), \u003cem\u003eCDKN2A\u003c/em\u003e (n\u0026thinsp;=\u0026thinsp;75, 70.0%) deletion, \u003cem\u003ePTEN\u003c/em\u003e deletion (n\u0026thinsp;=\u0026thinsp;48, 42.9%), \u003cem\u003eCDK4\u003c/em\u003e amp/gain (n\u0026thinsp;=\u0026thinsp;18, 16.1%), \u003cem\u003eMDM2\u003c/em\u003e amp/gain (n\u0026thinsp;=\u0026thinsp;18, 16.1%), \u003cem\u003eNFKBIA\u003c/em\u003e deletion (n\u0026thinsp;=\u0026thinsp;18, 16.1%), and \u003cem\u003eTP53\u003c/em\u003e hemizygous deletion (n\u0026thinsp;=\u0026thinsp;10, 10.7%).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eRegarding postoperative treatments, all patients received combined radiation and chemotherapy with temozolomide. Bevacizumab was administered as a second-line therapy in 67 patients. Tumor-treating therapy was administered in 6 patients after radiation.\u003c/p\u003e \u003cp\u003e \u003cb\u003eCorrelation analyses between the\u003c/b\u003e \u003cb\u003eTERT\u003c/b\u003e\u003cb\u003ep status and other prognostic factors\u003c/b\u003e\u003c/p\u003e \u003cp\u003eThe preoperative KPS was higher in patients with \u003cem\u003eTERT\u003c/em\u003ep mutant versus \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.009) (Table\u0026nbsp;1). Loss of ATRX, \u003cem\u003ePDGFR\u003c/em\u003e amplification/gain, \u003cem\u003eMDM2\u003c/em\u003e amplification/gain, and \u003cem\u003eTP53\u003c/em\u003e hemizygous deletion were more frequent in \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.005, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.009, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.033, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.009, respectively), whereas \u003cem\u003eEGFR\u003c/em\u003e amplification/gain and \u003cem\u003ePTEN\u003c/em\u003e deletion were more frequent in \u003cem\u003eTERT\u003c/em\u003ep mutant GBM (both \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Table\u0026nbsp;1). No correlations were observed for other factors (Table\u0026nbsp;1).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eUnivariate analysis for the prediction of PFS and OS\u003c/h2\u003e \u003cp\u003ePatients with \u003cem\u003eIDH\u003c/em\u003e wild-type GBM had a median PFS of 7 months and a median OS of 20 months (Table\u0026nbsp;2). Based on the Kaplan\u0026ndash;Meier analysis, longer PFS and OS correlated with RANO class 1/2A (complete resection of the CE tumor) (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.025 and \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.012, respectively) (Supplementary Fig.\u0026nbsp;1A and B). \u003cem\u003eCDKN2A\u003c/em\u003e deletion was correlated with OS (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.015) (Supplementary Fig.\u0026nbsp;1C and D).\u003c/p\u003e \u003cp\u003eAmong patients with \u003cem\u003eTERT\u003c/em\u003ep mutant GBM, there were significant differences in PFS (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.012) and OS (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.003) between RANO class 1/2A versus RANO class 2B/3 (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA and B, Table\u0026nbsp;3). Moreover, \u003cem\u003eMGMT\u003c/em\u003ep methylation was significantly correlated with PFS and OS (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.010 and \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.010, respectively) (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eC and D, Table\u0026nbsp;3), whereas \u003cem\u003eCDKN2\u003c/em\u003eA deletion had no correlation with either (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eE and F, Table\u0026nbsp;3).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAmong patients with \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM, there were no significant differences in PFS and OS among RANO class 1/2A versus RANO class 2B/3 (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.265 and \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.391, respectively) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA and B, Table\u0026nbsp;3) and among patients with versus without \u003cem\u003eMGMT\u003c/em\u003ep methylation (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.906 and \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.371, respectively) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eC and D, Table\u0026nbsp;3). \u003cem\u003eCDKN2A\u003c/em\u003e deletion was strongly correlated with poor OS (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001) (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eE and F, Table\u0026nbsp;3).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eMultivariate analysis of prognostic factors\u003c/h2\u003e \u003cp\u003eThe multivariate analysis for PFS and OS included the following factors: age, extent of resection (RANO class), \u003cem\u003eMGMT\u003c/em\u003e gene promoter methylation, and \u003cem\u003eCDKN2A\u003c/em\u003e deletion (Supplementary Table\u0026nbsp;1). The absence of total CE tumor resection (RANO class 1/2A) was an independent predictor of unfavorable prognosis in terms of both PFS (hazard ratio [HR]: 1.6, 95% confidence interval [CI]: 1.1\u0026ndash;2.4, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.024) and OS (HR: 1.9, 95% CI: 1.2\u0026ndash;2.7, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.008). Meanwhile, \u003cem\u003eCDKN2A\u003c/em\u003e deletion independently predicted poor OS (HR: 1.3, 95% CI: 1.1\u0026ndash;3.0, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e \u003cp\u003eAmong patients with \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM, \u003cem\u003eCDKN2A\u003c/em\u003e deletion was the sole factor that independently predicted poor OS (HR: 5.0, 95% CI: 1.8\u0026ndash;13.6, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.002) (Supplementary Table\u0026nbsp;2).\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe \u003cem\u003eTERT\u003c/em\u003ep mutation has been found in approximately 70%\u0026ndash;80% of patients with \u003cem\u003eIDH\u003c/em\u003e wild-type GBM [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. In our previous report, only 50%\u0026ndash;70% of Japanese patients with \u003cem\u003eIDH\u003c/em\u003e wild-type GBM were found to have the \u003cem\u003eTERT\u003c/em\u003ep mutation. The frequency of \u003cem\u003eTERT\u003c/em\u003ep mutation (62.5%) found in the present study is in line with previous reports from Japan [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAside from \u003cem\u003eTERT\u003c/em\u003ep mutations, \u003cem\u003eATRX\u003c/em\u003e or \u003cem\u003eSMARCAL\u003c/em\u003e1 gene mutations are also known mechanisms of tumor cell immortalization [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. In fact, ATRX loss is more common in patients with \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM. However, since the frequency of ATRX loss was not very high, other immortalization mechanisms are likely involved as well. Furthermore, unlike in \u003cem\u003eIDH-\u003c/em\u003emutant gliomas, \u003cem\u003eTERT\u003c/em\u003ep mutation and loss of ATRX expression are not mutually exclusive. Since it may be somewhat difficult to interpret the loss of ATRX expression on immunohistochemistry, \u003cem\u003eATRX\u003c/em\u003e mutation analysis may be necessary in the future.\u003c/p\u003e \u003cp\u003eThe clinical and prognostic impacts of \u003cem\u003eTERT\u003c/em\u003ep mutation remain controversial in patients with GBM. In other cancers, several studies have demonstrated its correlations with poor prognosis, aggressive clinicopathological characteristics, and metastasis [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. In our previous report, \u003cem\u003eTERT\u003c/em\u003ep mutation was significantly associated with shortened PFS and OS on univariate and multivariate analyses [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. However, in this cohort, patients with \u003cem\u003eTERT\u003c/em\u003ep mutations tended to have shorter OS than patients without mutations, although the difference was not statistically significant. Thus, the prognostic significance of \u003cem\u003eTERT\u003c/em\u003ep mutations will require further investigation in a larger number of cases.\u003c/p\u003e \u003cp\u003eIn a previous study, prognosis remained similar regardless of the presence of \u003cem\u003eMGMT\u003c/em\u003ep methylation, despite it being a well-known prognostic factor for GBM [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Similarly, several studies have shown that \u003cem\u003eMGMT\u003c/em\u003ep status has little prognostic impact among cases of \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. In fact, in our study, \u003cem\u003eMGMT\u003c/em\u003ep methylation was a favorable prognostic factor for both PFS and OS in \u003cem\u003eTERT\u003c/em\u003ep mutant GBM.\u003c/p\u003e \u003cp\u003eIn \u003cem\u003eIDH\u003c/em\u003e-mutant astrocytoma, homozygous \u003cem\u003eCDKN2A\u003c/em\u003e deletion is associated with poor prognosis; such cases are classified as WHO CNS grade 4. However, the prognostic impact of \u003cem\u003eCDKN2A\u003c/em\u003e deletion remains unclear in GBM [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. One recent report demonstrated that \u003cem\u003eTERTp\u003c/em\u003e mutations and \u003cem\u003eCDKN2A\u003c/em\u003e deletions occur in the early stage of GBM development [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Thus, the mechanism of development of \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM may be completely different from that of \u003cem\u003eTERT\u003c/em\u003ep mutant GBM. In the present analysis, \u003cem\u003eCDKN2A\u003c/em\u003e deletion did not affect prognosis in \u003cem\u003eTERT\u003c/em\u003ep mutant GBM, but it was a statistically significant factor for poor prognosis in \u003cem\u003eTERT\u003c/em\u003ep wild-type cases. Thus, the development of \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM may follow a similar mechanism as \u003cem\u003eIDH\u003c/em\u003e-mutant astrocytoma.\u003c/p\u003e \u003cp\u003eThe limitations of the present study must be acknowledged. First, this was a retrospective study with a small sample size. Second, it remains unclear why \u003cem\u003eMGMT\u003c/em\u003ep methylation was not identified as a prognostic factor. Lastly, the mechanism of temozolomide resistance in \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM warrants further investigation.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis retrospective study investigated whether \u003cem\u003eTERT\u003c/em\u003ep status influences the prognostic impact of certain clinicopathological factors in patients with GBM. \u003cem\u003eCDKN2A\u003c/em\u003e deletion was strongly associated with PFS and OS in \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCE\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003econtrast-enhanced\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGBM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eglioblastoma\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003eH3F3A\u003c/em\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eH3.3 histone A\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eIDH\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eisocitrate dehydrogenase\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003eIDH1\u003c/em\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eisocitrate dehydrogenase 1\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003eMGMT\u003c/em\u003e\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eO\u003csup\u003e6\u003c/sup\u003e-methylguanine-DNA methyltransferase\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMRI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003emagnetic resonance imaging\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eoverall survival\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePCR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003epolymerase chain reaction\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePFS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eprogression-free survival\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003e\u003cem\u003eTERT\u003c/em\u003ep\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003epromoter region of telomerase reverse transcriptase\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgments\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors thank Enago (https://www.enago.jp/)for the English-language review.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSK, YS: conception and design of the work. SK, YM, KN, KS, TK: data curation and writing of the original draft. YS: funding acquisition. MF, YK: writing, review, and editing.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThis work was supported by JSPS KAKENHI (Grant Number 23K08493 and 26K12030).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e\u003cstrong\u003e:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors declare that they have no conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eapproval:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThisstudy was approved by the Ethics Committee of Yamagata University Hospital (approval number: 2018-498).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInformed consent\u003c/strong\u003e\u003cstrong\u003e:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eInformed consent was provided by all participants included in the study.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLouis DN, Perry A, Brat DJ et al (2021) WHO Classification of Tumours of the Central Nervous System in The WHO Classification of Tumours Editorial Board (ed): World Health Organization Classification of Tumours (5th Edition), Lyon, IARC Press, 2021, pp 516\u0026ndash;552\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStupp R, Mason WP, van den Bent MJ et al (2015) Radiotherapy plus concomitant and adjuvant temozolomide for glioblastoma. 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Sci Signal 6:pl1\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCerami E, Gao J, Dogrusoz U et al (2012) The cBio cancer genomics portal: an open platform for exploring multidimensional cancer genomics data. Cancer Discov 2:401\u0026ndash;404\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWiestler B, Capper D, Holland-Letz T et al (2013) ATRX loss refines glioma classification. Acta Neuropathol 126:443\u0026ndash;451\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTakano S, Kato Y, Yamamoto T et al (2016) Ki-67 labeling index in gliomas. Brain Tumor Pathol 33:83\u0026ndash;88\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eArita H, Narita Y, Fukushima S et al (2013) TERT promoter mutations in gliomas. Acta Neuropathol 126:267\u0026ndash;276\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDiplas BH, He X, Brosnan-Cashman JA et al (2018) Genomic landscape of TERT wild-type glioblastoma. Nat Commun 9:2087\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYuan P, Cao JL, Abuduwufuer A et al (2016) TERT promoter mutations in cancer: meta-analysis. PLoS ONE 11:e0146803\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCampos MA, Macedo S, Fernandes M et al (2019) TERT promoter mutations and prognosis in carcinoma. J Am Acad Dermatol 80:660\u0026ndash;669\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarthel FP, Johnson KC, Varn FS et al (2019) Molecular trajectories of diffuse glioma. Nature 576:112\u0026ndash;120\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables 1 to 3 are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"brain-tumor-pathology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"btpa","sideBox":"Learn more about [Brain Tumor Pathology](http://link.springer.com/journal/10014)","snPcode":"10014","submissionUrl":"https://www.editorialmanager.com/btpa/default2.aspx","title":"Brain Tumor Pathology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"glioblastoma, TERT promoter, MGMT promoter, CDKN2A deletion","lastPublishedDoi":"10.21203/rs.3.rs-9350156/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9350156/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eThe most common alterations in \u003cem\u003eIDH\u003c/em\u003e wild-type primary glioblastoma (GBM) are mutations in the promoter region of the telomerase reverse transcriptase gene (\u003cem\u003eTERT\u003c/em\u003ep). This retrospective study investigated whether the impact of clinicopathological factors on prognosis in patients with GBM depends on \u003cem\u003eTERT\u003c/em\u003ep status.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eAmong 112 cases of \u003cem\u003eIDH\u003c/em\u003e wild-type GBM, 70 patients (62.5%) had the \u003cem\u003eTERT\u003c/em\u003ep mutation. Clinical, immunohistochemical, and genetic factors (ATRX expression, and O\u003csup\u003e6\u003c/sup\u003e-methylguanine-DNA methyltransferase promoter [\u003cem\u003eMGMT\u003c/em\u003ep] methylation), and copy number alterations (CNAs) were investigated.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eLoss of ATRX, \u003cem\u003ePDGFR\u003c/em\u003e amplification/gain, \u003cem\u003eMDM2\u003c/em\u003e amplification/gain, and \u003cem\u003eTP53\u003c/em\u003e hemizygous deletion were more frequent in patients with \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.005, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.009, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.033, \u003cem\u003eP\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.009, respectively). \u003cem\u003eEGFR\u003c/em\u003e amplification/gain and \u003cem\u003ePTEN\u003c/em\u003e deletion were more frequent in those with \u003cem\u003eTERT\u003c/em\u003ep mutant GBM (both \u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Postoperative residual tumor volume and \u003cem\u003eMGMT\u003c/em\u003ep methylation were significantly correlated with PFS and OS in patients with \u003cem\u003eTERT\u003c/em\u003ep mutant GBM. Only \u003cem\u003eCDKN2A\u003c/em\u003e deletion was strongly correlated with poor OS in patients with \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM (\u003cem\u003eP\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003e \u003cem\u003eCDKN2A\u003c/em\u003e deletion alone was associated with the prognosis of \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM. Therefore, \u003cem\u003eTERT\u003c/em\u003ep wild-type GBM may be a distinct clinical subtype of \u003cem\u003eIDH\u003c/em\u003e wild-type GBM.\u003c/p\u003e","manuscriptTitle":"CDKN2A deletion associated with poor prognosis in patients with TERT promoter wild-type, IDH wild-type glioblastoma","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-05-11 10:40:59","doi":"10.21203/rs.3.rs-9350156/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2026-05-01T00:04:40+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-30T20:06:12+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-15T15:27:49+00:00","index":"","fulltext":""},{"type":"submitted","content":"Brain Tumor Pathology","date":"2026-04-07T21:29:34+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"brain-tumor-pathology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"btpa","sideBox":"Learn more about [Brain Tumor Pathology](http://link.springer.com/journal/10014)","snPcode":"10014","submissionUrl":"https://www.editorialmanager.com/btpa/default2.aspx","title":"Brain Tumor Pathology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"a1a8877e-5eb5-47ba-8c13-8ff177e78bb1","owner":[],"postedDate":"May 11th, 2026","published":true,"recentEditorialEvents":[{"type":"reviewerAgreed","content":"","date":"2026-05-01T00:04:40+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-04-30T20:06:12+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-11T10:41:00+00:00","versionOfRecord":[],"versionCreatedAt":"2026-05-11 10:40:59","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9350156","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9350156","identity":"rs-9350156","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}