O6-methylguanine DNA Methyltransferase Promoter Methylation Research Articles

Evaluation of VAL-083 in GBM AGILE, a phase 3 registration platform trial for newly diagnosed and recurrent glioblastoma.

2005 Background: GBM AGILE (NCT03970447) is a phase 2/3 Bayesian adaptive registration platform trial testing multiple therapies efficiently against a common control (C) with a primary endpoint of overall survival (OS). VAL-083 (VAL) is a DNA targeting agent that, independent of O6-methylguanine DNA methyltransferase promoter methylation status, targets the N7 position of guanine residues and facilitates inter-strand DNA crosslinks, leading to DNA double-strand breaks and cell death. It entered the trial in January 2021, and it is the 2nd arm (of 6) to complete its evaluation. Methods: Patient subtypes considered in GBM AGILE are newly diagnosed methylated (NDM), ND unmethylated (NDU), & recurrent disease (RD). C is temozolomide (in ND) & lomustine (in RD). Arms open to all 3 subtypes are evaluated in 5 prospectively defined signatures (sig): NDU, NDM, RD, all ND and All. Randomization to C is 20% in each subtype. Exp arms in GBM AGILE have 1 or 2 stages. Efficacy is based on OS hazard ratio (HR) of arm/C. Efficacy goal is a final Bayesian probability ≥ 98% for HR <1.00 in combined Stages 1 & 2. Arms stop accruing in Stage 1 if they reach max sample size (N) or drop for futility or safety. Exp arms in Stage 1 are adaptively randomized with allocation being proportional to an arm’s current probability of having ≥ 30% benefit in OS, P(HR <0.70). In stage 1, exp arms are evaluated monthly, and arms showing Bayesian predictive power (PP) ≥ 0.8, graduate into Stage 2 with fixed randomization in one sig. For all exp arms, follow up continues for 12 mos after accrual stops (clinical cutoff). Arms are declared futile at any monthly analysis when PP is <0.25 for all sigs. Open to all 3 subtypes, VAL entered as the 1st arm in NDM and was randomized 1:1 to C in this subtype until additional arms entered. The target max N for VAL in its Stages 1 & 2 were 150 and 50, resp. Results: At the interim after VAL reached max sample size in Stage 1, the PP for all signatures was <0.8 and >0.25 for at least one sig. Thus, VAL did not graduate nor drop for futility, but accrual stopped for maximum N in Stage 1 (see table). Final results will be presented at the meeting. Columns 2-5 show results at the interim after which VAL stopped for max N. Columns 6-8 show near final results. Conclusions: GBM AGILE is an efficient & effective model for phase 3 drug development. VAL did not increase OS compared to C in any glioblastoma subtype. GBM AGILE evaluated this agent in less time, at lower cost, & with fewer patients than typical registration trials & is currently evaluating several other arms. Clinical trial information: NCT03970447 . [Table: see text]

Abstract CT230: Exploratory analyses of MGMT promoter methylation and PD-L1 expression from newly diagnosed glioblastoma patients in CheckMate 548 study suggest refinement in thresholds for predicting response to standard of care and nivolumab treatments

Abstract CheckMate 548 (NCT02667587, CM548) is a phase III, randomized trial evaluating first line nivolumab (NIVO) in combination with standard of care (SOC) [surgical resection followed by radiotherapy and temozolomide (TMZ)] versus placebo plus SOC in patients with newly diagnosed glioblastoma (GBM) positive for promoter methylation of O6-methylguanine DNA methyltransferase (MGMT). MGMT promoter methylation status and PD-L1 expression predict better outcomes in GBM patients treated with TMZ and in patients treated with NIVO in other indications, respectively. However, the impact of varying levels of MGMT promoter methylation and PD-L1 expression on patient outcome in GBM remains unclear. In CM548, MGMT promoter methylation levels were quantified through a central lab assay (LapCorp) and PD-L1 expression was determined by percentage of detectable membrane staining of tumor cells. MGMT methylation and PD-L1 data were prospectively generated at the time of enrolment. Our analyses showed that increasing levels of MGMT promoter methylation level were associated with longer overall survival in patients treated with SOC alone (n = 349). However, no survival benefit was observed with increasing levels of MGMT methylation in patients treated with NIVO in combination with SOC (n = 353). In addition, our data showed a non-linear relationship between PD-L1 expression and overall survival across both arms. In patients with intermediate PD-L1 expression (≥5%, <20%), longer survival was observed in the nivolumab + SOC arm compared to SOC alone. This benefit was not observed in patients with low (≥1%, <5%) and high (>20%) PD-L1 expression. Potential mechanisms driving these observed associations are currently explored using genomic data generated from patient samples. MGMT promoter methylation and PD-L1 expression are potential clinically relevant predictive biomarkers of response to treatments administered in the CM-548; however, the binary classification of positive/negative status of these markers does not fully capture their relationship with efficacy in CM548. Data generated from our exploratory analyses suggests that new, refined criteria are needed for better patient outcomes prediction. Citation Format: Yu-Han Hung, Aparna Chhibber, Michael Lim, Michael Weller, David A. Reardon, Antonio Omuro, Keith L. Ligon, Ana Lako, Ann Forslund. Exploratory analyses of MGMT promoter methylation and PD-L1 expression from newly diagnosed glioblastoma patients in CheckMate 548 study suggest refinement in thresholds for predicting response to standard of care and nivolumab treatments [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT230.

Combined Lanreotide Autogel and Temozolomide Treatment of Progressive Pancreatic and Intestinal Neuroendocrine Tumors: The Phase II SONNET Study.

In advanced neuroendocrine tumors (NET), antiproliferative treatment options beyond somatostatin analogs remain limited. Temozolomide (TMZ) has shown efficacy in NET alone or combined with other drugs. SONNET (NCT02231762) was an open, multicenter, prospective, phase II study to evaluate lanreotide autogel 120 mg (LAN) plus TMZ in patients with progressive advanced/metastatic grade 1/2 gastroenteropancreatic (GEP) NET or of unknown primary. Patients could be enrolled at first-line or higher therapy line. The primary endpoint was disease control rate ([DCR], rate of stable disease [SD], partial [PR], and complete response [CR]) at 6 months of LAN and TMZ. Patients with nonfunctioning (NF) NET without progression at 6 months were randomized to 6-month LAN maintenance or watch and wait, patients with functioning (F)-NET with clinical benefit (PR, SD) continued on LAN. Fifty-seven patients were recruited. The majority of patients received the study drug at second or higher treatment line and had an NET G2. DCR at 6 months LAN and TMZ was 73.5%. After 6 months of further LAN maintenance, 54.5% of patients with F-NET and 71.4% with NF-NET had SD or PR vs 41.7% with NF-NET on observation only. LAN and TMZ were effective in all subgroups analyzed. At 12 months of follow-up, median progression-free survival was 11.1 months. Median serum chromogranin A decreased except in NF-NET on observation. O6-methylguanine DNA methyltransferase promoter methylation appeared to better reflect TMZ response than loss of gene expression. During combination therapy, the most frequent treatment-emergent adverse events grade 3/4 reported were nausea (14%), thrombocytopenia (12.3%), and neutropenia (8.8%). Four deaths were reported resulting from severe adverse events not considered related to study medication. LAN plus TMZ is a treatment option for patients with progressive GEP-NET with more aggressive biological profile showing a manageable safety profile.

IDH-mutant grade 4 astrocytoma: a comparison integrating the clinical, pathological, and survival features between primary and secondary patients.

IDH-mutant grade 4 astrocytomas (AIDHmut/G4) are divided into primary de novo (pAIDHmut/G4) and secondary with a history of prior lower-grade gliomas (LGGs; sAIDHmut/G4). The mutational spectrum and DNA methylation patterns are homogeneous within de novo pAIDHmut/G4 and evolved sAIDHmut/G4, but the two groups have different diagnoses, management, and outcomes. This study sought to systematically compare the clinical, pathological, and survival characteristics between them. Of the 871 grade 4 astrocytomas with data for IDH mutation, 698 (80.1%) were primary and 173 (19.9%) were secondary. Of the 698 primary tumors, 103 (14.8%) were pAIDHmut/G4, and of the 173 secondary tumors, 108 (62.4%) were sAIDHmut/G4. Clinical, pathological, and survival features were compared between pAIDHmut/G4 and sAIDHmut/G4. Multivariate analyses were performed to identify prognostic factors. Patients with sAIDHmut/G4 had significantly shorter median overall survival (OS; 11.8 vs 34.2 months, hazard ratio [HR] 2.69, 95% confidence interval [CI] 1.367-5.306, p = 0.004) and progression-free survival (PFS; 8.5 vs 24.3 months, HR 2.83, 95% CI 1.532-5.235, p = 0.001) than patients with pAIDHmut/G4. In patients with sAIDHmut/G4, resection status and chemotherapy were independent prognostic factors for OS and PFS; in patients with pAIDHmut/G4, LGG component, resection status, and O6-methylguanine DNA methyltransferase promoter methylation were independent prognostic factors. The therapeutic strategies of LGGs did not influence survival of patients with sAIDHmut/G4, but patients who had not received radiotherapy or chemotherapy when they were diagnosed with LGGs were found to benefit from radiotherapy or chemotherapy when they progressed to sAIDHmut/G4. The different clinical characteristics, survival, and risk factors between sAIDHmut/G4 and pAIDHmut/G4 provide a reference to guide treatment decisions in AIDHmut/G4.

Zotiraciclib (TG02) for newly diagnosed glioblastoma in the elderly or for recurrent glioblastoma: The EORTC 1608 STEAM trial

BackgroundZotiraciclib (TG02) is an oral multi-cyclin dependent kinase (CDK) inhibitor thought to inhibit tumor growth via CDK-9-dependent depletion of survival proteins such as c-MYC and MCL-1 which are frequently overexpressed in glioblastoma. MethodsEORTC 1608 (NCT03224104) (STEAM) had a three parallel group (A,B,C) phase Ib, open-label, non-randomized, multicenter design in IDH wild-type newly diagnosed glioblastoma or anaplastic astrocytoma. Groups A and B explored the maximum tolerated dose (MTD) of TG02 in elderly patients, in combination with hypofractionated radiotherapy alone (group A) or temozolomide alone (group B), according to O6-methylguanine DNA methyltransferase promoter methylation status determined centrally. Group C explored single agent activity of TG02 at first relapse after temozolomide chemoradiotherapy with a primary endpoint of progression-free survival at 6 months (PFS-6). Tumor expression of CDK-9, c-MYC and MCL-1 was determined by immunohistochemistry. ResultsThe MTD was 150 mg twice weekly in combination with radiotherapy alone (group A) or temozolomide alone (group B). Two dose-limiting toxicities were observed at 150 mg: one in group A (grade 3 seizure), one in group B (multiple grade 1 events). Main toxicities included neutropenia, gastrointestinal disorders and hepatotoxicity. PFS-6 in group C was 6.7%. CDK-9, c-MYC and MCL-1 were confirmed to be expressed and their expression was moderately cross-correlated. High protein levels of MCL-1 were associated with inferior survival. ConclusionsTG02 exhibits overlapping toxicity with alkylating agents and low single agent clinical activity in recurrent glioblastoma. The role of CDK-9 and its down-stream effectors as prognostic factors and therapeutic targets in glioblastoma warrants further study.

CTNI-34. ZOTIRACICLIB (TG02) FOR NEWLY DIAGNOSED GLIOBLASTOMA IN THE ELDERLY OR FOR RECURRENT GLIOBLASTOMA: FINAL RESULTS OF THE EORTC 1608 STEAM TRIAL

Abstract BACKGROUND Zotiraciclib (TG02) is an oral multi-cyclin dependent kinase (CDK) inhibitor that is supposed to suppress tumor growth via CDK-9-dependent depletion of survival proteins such as c-MYC and MCL-1 which are frequently overexpressed in glioblastoma. METHODS EORTC 1608 (NCT03224104) (STEAM) had a three parallel group (A,B,C) phase Ib, open-label, non-randomized, multicenter design. Groups A and B explored the maximum tolerated dose (MTD) of TG02 in elderly patients with IDH1R132H-non-mutant newly diagnosed glioblastoma or anaplastic astrocytoma, in combination with hypofractionated radiotherapy alone (group A) or temozolomide alone (group B), based on O6-methylguanine DNA methyltransferase promoter methylation status determined centrally. Group C explored single agent activity of TG02 in IDH1R132H-non-mutant glioblastoma or anaplastic astrocytoma at first relapse after temozolomide chemoradiotherapy with a primary endpoint of progression-free survival at 6 months. Secondary objectives included efficacy, quality of life, and safety. Expression of CDK-9, c-MYC and MCL-1 was determined by immunohistochemistry. RESULTS The MTD was 150 mg twice weekly in combination with radiotherapy alone (group A) or temozolomide alone (group B) in elderly patients. Two dose-limiting toxicities were observed at 150 mg, one in group A (grade 3 seizure) and one in group B (multiple grade 1 events). Main toxicities included neutropenia, gastrointestinal disorders, and hepatotoxicity. Progression-free survival at 6 months in group C was 6.7%. CDK9 and its indirect targets, c-MYC and MCL-1, were confirmed to be expressed and their expression was correlated, supporting a regulatory role for CDK-9. The protein levels of CDK-9 and MCL-1 correlated with overall survival. CONCLUSION TG02 exhibits overlapping toxicity with alkylating agents and low clinical activity as a single agent. Larger randomized trials are required to explore activity in combination with RT or TMZ. The role of CDK-9 and its down-stream effectors as prognostic factors and therapeutic targets in glioblastoma warrants further study.

Zotiraciclib (TG02) for newly diagnosed glioblastoma in the elderly or for recurrent glioblastoma: The EORTC 1608 STEAM trial.

2054 Background: Zotiraciclib (TG02) is an oral multi-cyclin dependent kinase (CDK) inhibitor, including CDK-9, that inhibits tumor growth down-stream via depletion of survival proteins such as MCL-1 and MYC. MCL-1 and MYC are frequently overexpressed in glioblastoma. Methods: The EORTC 1608 (NCT03224104) (STEAM) phase 1b trial had a three parallel group (A,B,C) open-label, non-randomized, multicenter design. Groups A and B explored the maximum tolerated dose (MTD) of zotiraciclib in elderly patients (more than 65 years) with IDH1R132H-non-mutant newly diagnosed glioblastoma or anaplastic astrocytoma, in combination with hypofractionated radiotherapy alone (group A) or temozolomide alone (group B), based on O6-methylguanine DNA methyltransferase promoter methylation status determined centrally. Group C explored single agent activity of zotiraciclib in IDH1R132H-non-mutant glioblastoma or anaplastic astrocytoma at first relapse after temozolomide chemoradiotherapy with a primary endpoint of progression-free survival at 6 months. Secondary objectives included efficacy, quality of life, and safety. Results: The MTD was 150 mg in combination with radiotherapy alone (group A, n=12) or temozolomide alone (group B, n=9) in elderly patients. Two dose-limiting toxicities were observed at 150 mg, one in group A (grade 3 seizure) and one in group B (multiple grade 1 events). Main toxicities included neutropenia, gastro-intestinal disorders, and hepatotoxicity. Progression-free survival at 6 months in group C (n=50) was 6.7%. Conclusions: Zotiraciclib exhibits overlapping toxicity with alkylating agents and low clinical activity as a single agent. Larger randomized trials may be required to explore activity in combination with radiotherapy or temozolomide. Clinical trial information: NCT03224104 .

Development of a Standard Control for qMSP to Analyze the Methylation Status of LINE-1

Cancer screening is an important aspect of comprehensive health care, making a significant contribution to reducing the risk of death and the cost of treating patients. Finding new tumor markers with high sensitivity and specificity is a trend in the research activities in Vietnam as well as all over the world. Long interspersed element-1 (LINE-1), a large proportion of repeating DNA, is transposable to different positions in the genome. LINE-1 activity is controlled through DNA methylation (the CpG is attached with CH3), whereby LINE-1 is highly methylated in normal cells. However, in some types of cancer such as lung, breast, stomach, liver, rectum... changes in the methylation status LINE-1 have been noticed. To study the methylation status of the LINE-1 sequence, we used a quantitative methyl-specific PCR technique. This method requires a standard calibrator to quantify the rate of methylation. From the commercial methylated DNA (CpG Methylated Human Genomic DNA, Promega), we cloned two regions of the LINE-1 promoter corresponding to a reference sequence and an investigated one (target sequence) which are bisulfite transformed. As a result, we have created two recombinant plasmids, pRef-LINE1 and pMe-LINE1. The plasmids were mixed at 10% of methylation and could be used as a standard control for analyzing the DNA methylation of specimens from patients.
 Keywords: DNA methylation, DNA repeating sequence, LINE-1, quantitative methyl-specific-PCR (qMSP), tumor markers.
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Organochlorine pesticides induce promoter hypermethylation of MGMT in papillary thyroid carcinoma

BackgroundEnvironmental factors namely pesticides may contribute to the development of cancer through epigenetic mechanisms. In order to evaluate the impact of organochlorine pesticides (OCPs) on promoter methylation of O6-methylguanine-DNA methyltransferase (MGMT) in thyroid cancer, this research was designed. MethodsIn this study, DNA methylation profile of 61 papillary thyroid carcinoma (PTC) and 70 benign thyroid nodules (BTN) subjects was carried out. In order to measure MGMT gene promoter methylation, methylation-specific PCR (MSP) was used. ResultsHypermethylation of MGMT marker were found in PTC compare with BTN. Also, OCPs increased the odds ratio of methylation of MGMT (OR = 3.66, P = 0.001). Logistic regression analysis showed that OCPs enhance the methylation of MGMT. ConclusionThe results indicated that OCPs lead to PTC development through MGMT gene promoter hypermethylation. Furthermore, MGMT promoter methylation assessment could forecast PTC incidence.

Radiomic Analysis to Predict Outcome in Recurrent Glioblastoma Based on Multi-Center MR Imaging From the Prospective DIRECTOR Trial

BackgroundBased on promising results from radiomic approaches to predict O6-methylguanine DNA methyltransferase promoter methylation status (MGMT status) and clinical outcome in patients with newly diagnosed glioblastoma, the current study aimed to evaluate radiomics in recurrent glioblastoma patients.MethodsPre-treatment MR-imaging data of 69 patients enrolled into the DIRECTOR trial in recurrent glioblastoma served as a training cohort, and 49 independent patients formed an external validation cohort. Contrast-enhancing tumor and peritumoral volumes were segmented on MR images. 180 radiomic features were extracted after application of two MR intensity normalization techniques: fixed number of bins and linear rescaling. Radiomic feature selection was performed via principal component analysis, and multivariable models were trained to predict MGMT status, progression-free survival from first salvage therapy, referred to herein as PFS2, and overall survival (OS). The prognostic power of models was quantified with concordance index (CI) for survival data and area under receiver operating characteristic curve (AUC) for the MGMT status.ResultsWe established and validated a radiomic model to predict MGMT status using linear intensity interpolation and considering features extracted from gadolinium-enhanced T1-weighted MRI (training AUC = 0.670, validation AUC = 0.673). Additionally, models predicting PFS2 and OS were found for the training cohort but were not confirmed in our validation cohort.ConclusionsA radiomic model for prediction of MGMT promoter methylation status from tumor texture features in patients with recurrent glioblastoma was successfully established, providing a non-invasive approach to anticipate patient’s response to chemotherapy if biopsy cannot be performed. The radiomic approach to predict PFS2 and OS failed.

Telomerase reverse transcriptase promoter mutation– and O6-methylguanine DNA methyltransferase promoter methylation–mediated sensitivity to temozolomide in isocitrate dehydrogenase–wild-type glioblastoma: is there a link?

Aim of the studyBenefit from temozolomide (TMZ) chemotherapy in the treatment of isocitrate dehydrogenase (IDH)–wild-type glioblastoma is essentially limited to patients with O6-methylguanine DNA methyltransferase (MGMT) promoter–methylated tumours. Recent studies suggested that telomerase reverse transcriptase (TERT) promoter hotspot mutations may have an impact on the prognostic role of the MGMT status in patients with glioblastoma. MethodsMGMT promoter methylation and TERT promoter mutation status were retrospectively assessed in a prospective cohort of patients with IDH–wild-type glioblastoma of the German Glioma Network (GGN) (n = 298) and an independent retrospective cohort from Düsseldorf, Germany, and Zurich, Switzerland (n = 302). ResultsIn the GGN cohort, but not in the Düsseldorf/Zurich cohort, TERT promoter mutation was moderately associated with inferior outcomes in patients with MGMT promoter–unmethylated tumours (hazard ratio 1.74; 95% confidence interval: 1.07–2.82; p = 0.026). TERT promoter mutations were not associated with better outcomes in patients with MGMT promoter–methylated tumours in either cohort. The two different TERT promoter hotspot mutations (C228T and C250T) were not linked to distinct outcomes. ConclusionsAnalysis of two independent cohorts of patients with glioblastoma did not confirm previous data, suggesting that TERT promoter mutations confer an enhanced benefit from TMZ in patients with MGMT promoter–methylated glioblastoma. Thus, diagnostic testing for TERT promoter mutations may not be required for prediction of TMZ sensitivity in patients with IDH–wild-type glioblastoma.

MGMT Promoter Methylation and IDH1 Mutations Do Not Affect [18F]FDOPA Uptake in Primary Brain Tumors.

The aim of our study was to investigate the effects of methylation of O⁶-methylguanine-DNA methyltransferase promoter (MGMTp) and isocitrate dehydrogenase 1 (IDH 1) mutations on amino acid metabolism evaluated with 3,4-dihydroxy-6-[18F]-fluoro-l-phenylalanine ([18F] FDOPA) positron emission tomography/computed tomography (PET/CT). Seventy-two patients with primary brain tumors were enrolled in the study (33 women and 39 men; mean age 44 ± 12 years old). All of them were subjected to PET/CT examination after surgical treatment. Of them, 29 (40.3%) were affected by grade II glioma and 43 (59.7%) by grade III. PET/CT was scored as positive or negative and standardized uptake value ratio (SUVr) was calculated as the ratio between SUVmax of the lesion vs. that of the background. Statistical analysis was performed with the Mann–Whitney U test. Methylation of MGMTp was detectable in 61 out of the 72 patients examinated. Mean SUVr in patients without methylation of MGMTp was 1.44 ± 0.38 vs. 1.35 ± 0.48 of patients with methylation (p = 0.15). Data on IDH1 mutations were available for 43 subjects; of them, 31 are IDH-mutant. Mean SUVr was 1.38 ± 0.51 in patients IDH mutant and 1.46 ± 0.56 in patients IDH wild type. MGMTp methylation and IDH1 mutations do not affect [18F] FDOPA uptake in primary brain tumors and therefore cannot be assessed or predicted by radiopharmaceutical uptake parameters.

MRI Atlas of IDH Wild-Type Supratentorial Glioblastoma: Probabilistic Maps of Phenotype, Management, and Outcomes.

Background Tumor location is a main prognostic parameter in patients with glioblastoma. Probabilistic MRI-based brain atlases specifying the probability of tumor location associated with important demographic, clinical, histomolecular, and management data are lacking for isocitrate dehydrogenase (IDH) wild-type glioblastomas. Purpose To correlate glioblastoma location with clinical phenotype, surgical management, and outcomes by using a probabilistic analysis in a three-dimensional (3D) MRI-based atlas. Materials and Methods This retrospective study included all adults surgically treated for newly diagnosed IDH wild-type supratentorial glioblastoma in a tertiary adult surgical neuro-oncology center (2006-2016). Semiautomated tumor segmentation and spatial normalization procedures to build a 3D MRI-based atlas were validated. The authors performed probabilistic analyses by using voxel-based lesion symptom mapping technology. The Liebermeister test was used for binary data, and the generalized linear model was used for continuous data. Results A total of 392 patients (mean age, 61 years ± 13; 233 men) were evaluated. The authors identified the preferential location of glioblastomas according to subventricular zone, age, sex, clinical presentation, revised Radiation Therapy Oncology Group-Recursive Partitioning Analysis class, Karnofsky performance status, O6-methylguanine DNA methyltransferase promoter methylation status, surgical management, and survival. The superficial location distant from the eloquent area was more likely associated with a preserved functional status at diagnosis (348 of 392 patients [89%], P < .05), a large surgical resection (173 of 392 patients [44%], P < .05), and prolonged overall survival (163 of 334 patients [49%], P < .05). In contrast, deep location and location within eloquent brain areas were more likely associated with an impaired functional status at diagnosis (44 of 392 patients [11%], P < .05), a neurologic deficit (282 of 392 patients [72%], P < .05), treatment with biopsy only (183 of 392 patients [47%], P < .05), and shortened overall survival (171 of 334 patients [51%], P < .05). Conclusion The authors identified the preferential location of isocitrate dehydrogenase wild-type glioblastomas according to parameters of interest and provided an image-based integration of multimodal information impacting survival results. This suggests the role of glioblastoma location as a surrogate and multimodal parameter integrating several known prognostic factors. © RSNA, 2019 Online supplemental material is available for this article. See also the editorial by Huang in this issue.

Super-early initiation of temozolomide prolongs the survival of glioblastoma patients without gross-total resection: a retrospective cohort study.

The optimal timing of chemoradiotherapy in patients with newly diagnosed glioblastoma (GBM) remains unclear. In this study, we explored the clinical efficacy of super-early initiation of temozolomide (TMZ) in the treatment interval from surgery to radiotherapy. We retrospectively reviewed the clinical data of375 patients with GBM in our institution from 2012 to 2018. One hundred and sixty-three patients received super-early TMZ within 7 days after craniotomy based on standard Stupp protocol (super-early group, SEG), while two hundred and twelve patients underwent standard Stupp protocol alone (control group, CG). We performed propensity score matching (PSM) to reduce patient selection bias between the two groups. Before PSM, both median progression-free survival (PFS) and overall survival (OS) of patients in SEG were longer than those in CG (PFS 11.5 vs. 9.0months, P = 0.0384 and OS23.0 vs. 17.0months, P = 0.0014). After PSM, the clinical efficacy of super-early initiation of TMZ only remained significant in term of OS, which was further validated in Cox hazard proportional model (HR=0.583, 95% CI 0.384-0.884, P=0.011). In the subgroup analysis, patients without gross total resection (GTR) or with O6-methylguanine DNA methyltransferase promoter methylation could benefit from super-early initiation of TMZ in both PFS and OS (P < 0.05). No significant difference of treatment emerging adverse events was observed between the two groups (P > 0.05). This retrospective study highlights that super-early initiation of TMZ in newly diagnosed GBM may confer to survival benefit, especially for those without GTR.

FoxD2-AS1 is a prognostic factor in glioma and promotes temozolomide resistance in a O6-methylguanine-DNA methyltransferase-dependent manner.

Glioma is the most common brain tumor with a dismal prognosis. While temozolomide (TMZ) based chemotherapy significantly improves survival in glioma patients, resistance against this compound commonly leads to glioma treatment failure. Overexpression of long-noncoding RNA (LncRNA) FoxD2 adjacent opposite strand RNA 1 (FoxD2-AS1) was identified to promote glioma development, but the role in TMZ resistance remains unclear. In this paper, we found that FoxD2-AS1 was overexpressed in recurrent glioma, high FoxD2-AS1 expression was significantly correlated with poor patient outcome. Methylation of O6-methylguanine-DNA methyltransferase (MGMT) is significantly less frequent in high FoxD2-AS1 expression patients. Knockdown of FoxD2-AS1 decreased the proliferation, metastatic ability of glioma cells and promote the sensitivity to TMZ in glioma cells. Furthermore, knockdown of FoxD2-AS1 induced hypermethylation of the promoter region of MGMT. Our data suggested that FoxD2-AS1 is a clinical relevance LncRNA and mediates TMZ resistance by regulating the methylation status of the MGMT promoter region.

Ten genes associated with MGMT promoter methylation predict the prognosis of patients with glioma.

Glioma originates from the glial cells of the spine or brain, and promoter methylation of O6-methylguanine-DNA methyltransferase (MGMT) can promote the chemosensitivity of glioma. The present study aimed to reveal the key genes implicated in MGMT promoter methylation in patients with glioma. RNA-sequencing data and methylation data for glioma were extracted from The Cancer Genome Atlas database. Following expression characteristic analysis and differential expression analysis using unsupervised hierarchical clustering and a rank sum test, the feature genes were identified between high and low methylation groups. Furthermore, multivariate survival analysis for the feature genes was performed using the survival package in R. Additionally, the independent glioma RNA expression datasets GSE7696 and GSE42669 were used to validate the prognostic efficiency of the gene combination. The results indicated that the prognosis of the low methylation group was significantly worse than that of the high methylation group. The ten genes corresponding to the cut-off value of 0.56 (Rho GTPase-activating protein 21, CECR2, histone acetyl-lysine reader, endosulfine α, G-patch domain-containing 8, KIAA1109, MGMT, protocadherin β 13, selenoprotein M, sperm-associated antigen 9 and WD repeat domain 6) were able to significantly predict prognosis and were differentially expressed between the two groups. Multivariate survival analysis suggested that the ten genes were effective for sample classification and prognostic prediction. Furthermore, the validation datasets confirmed the correlation of the ten genes with prognosis. In conclusion, these 10 genes may be mediated by MGMT promoter methylation in glioma. In addition, the ten-gene combination may be associated with the prognosis of patients with glioma.

Predictors of Response to Autologous Dendritic Cell Therapy in Glioblastoma Multiforme.

Glioblastoma (GBM) is the most common and lethal primary malignant glioma in adults. Dendritic cell (DC) vaccines have demonstrated promising results in GBM clinical trials. However, some patients do not respond well to DC therapy, with survival rates similar to those of conventional therapy. We retrospectively analyzed clinical and laboratory data to evaluate the factors affecting vaccine treatment. Forty-seven patients with de novo GBM were enrolled at China Medical University Hospital between 2005 and 2010 and divided into two subgroups. One subgroup of 27 patients received postsurgical adjuvant immunotherapy with autologous dendritic cell/tumor antigen vaccine (ADCTA) in conjunction with conventional treatment of concomitant chemoradiotherapy (CCRT) with temozolomide. The other 20 patients received only postsurgical conventional treatment without immunotherapy. Immunohistochemistry for CD45, CD4, CD8, programed death ligand 1 (PD-L1), and programed death 1 (PD-1) was performed on sections of surgical tumor specimens and peripheral blood mononuclear cells (PBMCs). Pearson's correlation, Cox proportional hazard model, and Kaplan-Meier analyses were performed to examine the correlations between the prognostic factors and survival rates. Younger age (<57 years), gross total resection, and CCRT and PD-1+ lymphocyte counts were significant prognostic factors of overall survival (OS) and progression-free survival (PFS) in the ADCTA group. Sex, CD45+ lymphocyte count, CD4+ or CD8+ lymphocyte count, tumor PD-L1 expression, isocitrate dehydrogenase 1 mutation, and O6 methylguanine-DNA methyltransferase promoter methylation status were not significant factors in both groups. In the ADCTA group, patients with tumor-infiltrating lymphocytes (TILs) with a lower PD-1+/CD8+ ratio (≤0.21) had longer OS and PFS (median OS 60.97 months, P < 0.001 and PFS 11.2 months, P < 0.008) compared to those with higher PD-1+/CD8+ ratio (>0.21) (median OS 20.07 months, P < 0.001 and PFS 4.43 months, P < 0.008). Similar results were observed in patients' PBMCs; lymphocyte counts with lower PD-1+/CD8+ ratio (≤0.197) had longer OS and PFS. There was a significant correlation of PD-1+/CD8+ ratio between TILs and PBMCs (Pearson's correlation R2 = 0.6002, P < 0.001). By contrast, CD4-, CD8-, but PD-1+, CD45+ tumor-infiltrating lymphocytes have no impact on OS and PFS (P = 0.073 and P = 0.249, respectively). For patients receiving DC vaccine adjuvant therapy, better outcomes are predicted in patients with younger age, with TILs or PBMCs with lower PD-1+/CD8+ ratio, with gross tumor resection, and receiving CCRT.

Association between MGMT Promoter Methylation and Risk of Breast and Gynecologic Cancers: A Systematic Review and Meta-Analysis

The role of the promoter methylation of O6-methylguanine-DNA methyltransferase (MGMT) remains controversial for breast and gynecologic cancers. We conducted a meta-analysis to assess the association between hypermethylation of MGMT promoter and the risk of breast and gynecologic cancers. A comprehensive search was conducted in PubMed and Embase electronic databases up to 19th August 2017 for studies about the association between MGMT promoter hypermethylation and breast and gynecologic cancers. A total of 28 articles including 2,171 tumor tissues and 1,191 controls were involved in the meta-analysis. The pooled results showed that MGMT promoter methylation status was significantly associated with an increased risk of breast and gynecologic cancers (OR = 4.37, 95% CI: 2.68–7.13, P < 0.05). The associations were robust in subgroup analysis based on ethnicity, cancer type, methylation detection method, and control source. This meta-analysis indicated that MGMT hypermethylation was significantly associated with the risk of breast and gynecological cancers, and it may be utilized as a valuable biomarker in early diagnostics and prognostication of these cancers. Further efforts are needed to identify and validate this finding in prospective studies, especially in situation with new methylation testing methods and samples from plasma circulating DNA.

Promoter methylation of MGMT in oral carcinoma: A population-based study and meta-analysis

IntroductionThe relevance of DNA methylation of O6-methylguanine-DNA methyltransferase (MGMT) in relation to several cancers and other disorders has been extensively explored in several cancer types. AimsTo ascertain the significance of DNA methylation of MGMT promoter in oral squamous cell carcinoma (OSCC), we undertook a study to a) analyse the methylation patterns of MGMT gene promoter in afflicted and normal population of coastal Karnataka, b) determine the expression status of MGMT in oral cancer cell lines (CAL-27 and SCC-4) and its relationship to DNA methylation and c) performed a meta-analysis of the published data. MethodsBisulfite sequencing of MGMT promoter region was performed on non-malignant/malignant oral samples, and oral cancer cell lines, followed by gene expression studies. Further, using a systematic search, 1024 publications were retrieved from PubMed, Scopus, Google Scholar and Web of Science and 23 relevant articles were reviewed. ResultsSignificant association of MGMT promoter methylation with OSCC (p<0.0001) was observed in the case-control study. The studies chosen for meta-analysis showed predictive significance of MGMT gene promoter. Overall, we obtained a statistically significant (p<0.0001) association for both sensitivity and specificity of MGMT DNA promoter methylation in oral cancer cases without publication bias. Gene expression was significantly elevated in both oral cancer cell lines (p<0.03) after treatment with a demethylating agent (5-Aza-2′-deoxycytidine). ConclusionDNA promoter hypermethylation and gene expression of MGMT may associate with recursive mutagenesis and is a promising biomarker for OSCC prediction. Studies suggest further validation in large distinct cohorts to facilitate translation to clinics.

MPTH-07GLIOBLASTOMAS: CORRELATION OF MGMT GENE PROMOTER METHYLATION WITH CLINICO-PATHOLOGICAL AND MOLECULAR PARAMETERS

Methylation of O6-methylguanine DNA methyltransferase (MGMT) is one of the predictive and prognostic markers of glioblastomas (GBMs). In this study, GBMs have been evaluated for the same and correlated with other clinicopathological and molecular parameters. MATERIALS AND METHODS: Diagnosed cases of GBM, during the period of June 2014 to December 2014 in the Department of Pathology of our Institute, wherein they have been evaluated for MGMT methylation by methylation specific polymerase chain reaction, IDH1R132H and p53 protein expression by immunohistochemistry and EGFR gene amplification by fluorescence in-situ hybridisation formed the study sample. Statistical correlation was done by Chi-square and Fischer's exact, using IBM SPSS Software 16 version. RESULTS: A total of 97 cases of GBM formed the study sample with age range of 20-75 years (mean age:49.76 years) and male: female ratio of 3.2:1 (M:74;F:23).Cerebral hemispheric location was commonest (frontal:35%; temporal:43 & parietal:19%). 46 (47.4%) cases were MGMT methylated (low methylation: 10) and 51 were unmethylated. 23 out of 84 cases (27.4%) were EGFR amplified; 10 cases (10.3%) were positive for IDH1R132H; 16 showed loss of ATRX protein expression (of which 7 were IDH1R132H positive; while the other 3 IDHR132H positive cases showed retained ATRX protein). Of the 46 MGMT methylated cases, 10 were EGFR amplified (10 out of 23 EGFR amplified cases were MGMT methylated); 5 were IDH1R132H positive and 6 showed loss of ATRX expression. None of the molecular markers showed any correlation for the histological features of calcification and necrosis (neither for pseudopalisading or confluent). CONCLUSIONS: MGMT was methylated in 47.4%of GBMs and had no significant statistical correlation with EGFR gene amplification, IDH1R132H mutation, ATRX protein expression and other histomorphological features. This study did not identify any surrogate marker for MGMT promoter methylation.