scholarly journals BIOM-31. PROGNOSTIC VALUE OF MGMT METHYLATION IN IDH MUTANT GLIOMAS

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii8-ii8
Author(s):  
Keng Lam ◽  
Blaine Eldred ◽  
Bryan Kevan ◽  
Matthew Ji ◽  
Jerry Lou ◽  
...  

Abstract BACKGROUND Patients with isocitrate dehydrogenase (IDH) mutant gliomas have been associated with longer survival time than those with IDH wildtype. Previous studies have also shown the predictive value of O-6-methylguanine-DNA methyltransferase (MGMT) promoter methylation for glioblastoma. However, little is known in the prognostic value of MGMT methylation status for IDH mutant gliomas. METHODS We retrospectively identified IDH mutant gliomas patients from University of California Los Angeles and Kaiser Permanente Los Angeles that had been tested for MGMT methylation status. We performed Kaplan-Meier and Cox regression analyses of overall survival (OS) to compare the MGMT methylated versus MGMT unmethylated patients. RESULTS We identified a total of 375 IDH mutant gliomas with MGMT testing. Subgroups include 52 glioblastoma, 191 astrocytoma, and 132 oligodendroglioma. The median OS for all MGMT methylated patients was 20.0 years and for unmethylated patients 14.3 years (log-rank P=0.008). Cox regression analysis also confirmed patients with MGMT methylated to have better survival than those with MGMT unmethylated (hazard ratio of 0.47, P= 0.005). During subgroup analysis, MGMT methylated glioblastoma patients have a median OS of 13.7 years compared to MGMT unmethylated patients 3.2 years (log-rank P=0.004) with a hazard ratio of 0.14 (P=0.005). However, we see no difference yet for astrocytoma (hazard ratio of 1.09, P= 0.81) and oligodendrogliomas (hazard ratio of 0.36, P= 0.193), possibly as a result of immature survival data. CONCLUSIONS MGMT promoter methylation is associated with better outcomes in IDH mutant glioblastoma patients. Progression free survival will be analyzed to determine predictive benefit of MGMT methylation for other glioma subtypes.

2017 ◽  
Vol 35 (15_suppl) ◽  
pp. 2048-2048
Author(s):  
Lorenzo Gerratana ◽  
Giuseppe Lombardi ◽  
Elisa De Carlo ◽  
Vanessa Buoro ◽  
Giovanna De Maglio ◽  
...  

2048 Background: The methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) promoter has been associated with improved outcome in glioblastoma (GBM) patients (pts). Pyrosequencing (PSQ) has been reported to be an accurate method for quantitative detection of CpG islands (CpGs) methylation, but the role of methylation heterogeneity among different CpGs sites is still unclear. Aim of this study was to evaluate on a large multicentric cohort a novel prognostic score based on the evaluation of the MGMT promoter methylation at 10 different CpGs sites. Methods: We retrospectively analyzed a series of 185 pts with GBM treated at the University Hospital of Udine and Istituto Oncologico Veneto in Padua between 2006 and 2015. The methylation level of 10 CpGs (74 – 83) was determined by PSQ. The cut-off point of 9% was used to define a CpG as methylated. One point was assigned to each methylated CpG, with a total score from 0 (all CpGs < 9%) to 10 (all CpGs ≥ 9%). A threshold capable to detect a favorable outcome (Overall Survival, OS > 24 months) has been identified through ROC analysis as 6 by a previous study conducted at our center. The prognostic impact was explored through Cox regression. Results: After a median follow-up of 59 months, the median OS and Progression Free Survival (PFS) in the whole population were 16.41 and 9.67 months, respectively. A score ≥ 6 identified pts with a considerably better median OS (24.85 vs 12.99 months, p < .0001) and PFS (11.44 vs 8.22 months, p < .0001). On multivariate analysis, it remained independently associated with a favorable prognosis (HR 0.38, 95% CI 0.27-0.55, p < 0.0001) after adjustment for IDH1 mutational status (HR 0.42, 95% CI 0.20-0.87, p = .02), age ( > 70 vs ≤ 70 years HR 2.20, 95% CI 1.48-3.28, p = .0001) and ECOG performance status (2-3 vs 0-1 HR 2.35, 95% CI 1.59-3.49, p < .0001). The score’s prognostic value was maintained in all the explored subgroups. Conclusions: Combining methylation data from multiple CpGs increases the prognostic value of the MGMT promoter methylation assessment. The study confirmed the independent prognostic value of a novel score system based on the evaluation of the MGMT promoter methylation at 10 different CpGi sites.


Medicina ◽  
2019 ◽  
Vol 55 (2) ◽  
pp. 34
Author(s):  
Nikola Jovanović ◽  
Tatjana Mitrović ◽  
Vladimir J. Cvetković ◽  
Svetlana Tošić ◽  
Jelena Vitorović ◽  
...  

Background and objective: Despite recent advances in treatment, glioblastoma (GBM) remains the most lethal and aggressive brain tumor. A continuous search for a reliable molecular marker establishes the methylation status of the O6-methylguanine-DNA methyltransferase (MGMT) gene promoter as a key prognostic factor in primary glioblastoma. The aim of our study was to screen Serbian patients with primary glioblastoma for an MGMT promoter hypermethylation and to evaluate its associations with overall survival (OS) and sensitivity to temozolomide (TMZ) treatment. Materials and methods: A cohort of 30 Serbian primary glioblastoma patients treated with radiation therapy and chemotherapy were analyzed for MGMT promoter methylation and correlated with clinical data. Results: MGMT methylation status was determined in 25 out of 30 primary glioblastomas by methylation-specific PCR (MSP). MGMT promoter hypermethylation was detected in 12 out of 25 patients (48%). The level of MGMT promoter methylation did not correlate with patients’ gender (p = 0.409), age (p = 0.536), and OS (p = 0.394). Treatment with TMZ significantly prolonged the median survival of a patient (from 5 to 15 months; p < 0.001). Conclusions: Due to a small cohort of primary GBM patients, our study is not sufficient for definitive conclusions regarding the prognostic value of MGMT methylation for the Serbian population. Our preliminary data suggest a lack of association between MGMT promoter methylation and overall survival and a significant correlation of TMZ treatment with overall survival. Further population-based studies are needed to assess the prognostic value of the MGMT promoter methylation status for patients with primary glioblastoma.


2020 ◽  
Author(s):  
ji zhang ◽  
Xiaoli Wang ◽  
Shengquan Ye ◽  
Lijiao Liang ◽  
Yi Zhou ◽  
...  

Abstract Background Understanding the molecular landscape of glioblastoma (GBM) is increasingly crucial for its therapy. Immune checkpoint molecules motivated the emergence of immune checkpoint-targeting therapeutic strategies. However, the prognostic significance of the immune checkpoint molecule T cell immunoglobulin mucin-3 (Tim-3) on tumor-infiltrating immune cells (TIICs) and O-6-Methylguanine-DNA methyltransferase (MGMT) methylation status remains to be fully elucidated. We aimed to develop an MGMT methylation status-associated immune prognostic signature for predicting prognosis in GBMs.Patients and Methods: A total of 84 patients with newly diagnosed GBM were involved. MGMT methylation status was retrospectively analyzed and the expression level of Tim-3 protein was investigated using immunohistochemistry (IHC). The correlation between Tim-3 protein expression and MGMT methylation status, and the prognosis was explored.Results The obtained data showed that Tim-3 protein was expressed at different levels in GBMs. Mesenchymal expression of Tim-3 protein in these tissues was 73.81% (62/84), including low 15.48% (13/84), moderate 7.14% (6/84) and strong expression 51.19% (43/84), respectively. Of the 48 patients whose tumors tested positive for MGMT methylation, the remaining 36 patients was negative.Conclusions We profiled the immune status in GBM with MGMT promoter methylation and established a local immune signature for GBM, which could independently identify patients with a favorable prognosis, indicating the relationship between prognosis and immune. MGMT promoter methylation with lower Tim-3 protein expression was statistically significantly associated with better survival.


2020 ◽  
Vol 10 (3) ◽  
pp. 128 ◽  
Author(s):  
Nguyen Quoc Khanh Le ◽  
Duyen Thi Do ◽  
Fang-Ying Chiu ◽  
Edward Kien Yee Yapp ◽  
Hui-Yuan Yeh ◽  
...  

Approximately 96% of patients with glioblastomas (GBM) have IDH1 wildtype GBMs, characterized by extremely poor prognosis, partly due to resistance to standard temozolomide treatment. O6-Methylguanine-DNA methyltransferase (MGMT) promoter methylation status is a crucial prognostic biomarker for alkylating chemotherapy resistance in patients with GBM. However, MGMT methylation status identification methods, where the tumor tissue is often undersampled, are time consuming and expensive. Currently, presurgical noninvasive imaging methods are used to identify biomarkers to predict MGMT methylation status. We evaluated a novel radiomics-based eXtreme Gradient Boosting (XGBoost) model to identify MGMT promoter methylation status in patients with IDH1 wildtype GBM. This retrospective study enrolled 53 patients with pathologically proven GBM and tested MGMT methylation and IDH1 status. Radiomics features were extracted from multimodality MRI and tested by F-score analysis to identify important features to improve our model. We identified nine radiomics features that reached an area under the curve of 0.896, which outperformed other classifiers reported previously. These features could be important biomarkers for identifying MGMT methylation status in IDH1 wildtype GBM. The combination of radiomics feature extraction and F-core feature selection significantly improved the performance of the XGBoost model, which may have implications for patient stratification and therapeutic strategy in GBM.


2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii1-ii1
Author(s):  
Yasin Mamatjan ◽  
Jeffrey Zuccato ◽  
Fabio Moraes ◽  
Michael Cabanero ◽  
Wumairehan Shali ◽  
...  

Abstract EGFR-mutant lung adenocarcinomas (EGFRm-LUAD) have a higher risk of developing brain metastases (BM) compared to non-EGFR-mutant tumors. BM development has significant prognostic impact and leads to poorer patient survival. MGMT promoter methylation is known to determine response to therapy in other cancer types including intracranial gliomas but has not been investigated in EGFRm-LUAD BM. This work aims to assess whether MGMT promoter methylation predicts patient survival or BM development in EGFRm-LUAD patients. A large cohort of 90 primary EGFRm-LUAD tumors, of which 33 (37%) developed BM, were profiled using the Illumina Infinium MethylationEPIC Bead chip. Using the previously reported MGMT-STP27 approach that uses two CpG sites to predict MGMT methylation status, Cox modeling was performed to assess whether MGMT methylation status correlates with overall survival independent of other clinical factors. MGMT methylation significantly predicted poorer survival in EGFRm-LUAD patients that developed BM (p=0.0003) and did not develop BM (p=0.003). A multivariate cox analysis, adjusting for cancer stage and smoking status as potential confounders, showed that MGMT methylation (HR=6.2, 95%CI:2.2–17.4, p=0.0005) and BM development (HR=2.6, 95%CI:1.3–5.3, p=0.007) were both independently predictive of worse overall survival in EGFRm-LUAD patients. This finding of poorer survival in MGMT methylated EGFRm-LUAD is validated in an independent LUAD patient cohort. Total mutation burden, calculated by the number of mutations per megabase of DNA, was substantially higher in MGMT methylated tumours with an interquartile range (IQR) of 58 (30–71) compared to MGMT unmethylated tumours with the IQR of 5.5 (4.3–6.1) resulting p-value of 0.01 for this comparison. Overall, this work shows that MGMT promoter methylation status is an important prognostic biomarker in LUAD patients. MGMT promoter methylation status in EGFRm–LUAD patients with BM may be used to guide patient treatment with potentially a greater extent of treatment for high-risk patients.


2018 ◽  
Author(s):  
Katie Storey ◽  
Kevin Leder ◽  
Andrea Hawkins-Daarud ◽  
Kristin Swanson ◽  
Atique U. Ahmed ◽  
...  

AbstractTumor recurrence in glioblastoma multiforme (GBM) is often attributed to acquired resistance to the standard chemotherapeutic agent temozolomide (TMZ). Promoter methylation of the DNA repair gene MGMT has been associated with sensitivity to TMZ, while increased expression of MGMT has been associated with TMZ resistance. Clinical studies have observed a downward shift in MGMT methylation percentage from primary to recurrent stage tumors. However, the evolutionary processes driving this shift, and more generally the emergence and growth of TMZ-resistant tumor subpopulations, are still poorly understood. Here we develop a mathematical model, parameterized using clinical and experimental data, to investigate the role of MGMT methylation in TMZ resistance during the standard treatment regimen for GBM (surgery, chemotherapy and radiation). We first find that the observed downward shift in MGMT promoter methylation status between detection and recurrence cannot be explained solely by evolutionary selection. Next, our model suggests that TMZ has an inhibitory effect on maintenance methylation of MGMT after cell division. Finally, incorporating this inhibitory effect, we study the optimal number of TMZ doses per adjuvant cycle for GBM patients with high and low levels of MGMT methylation at diagnosis.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi143-vi143
Author(s):  
Toru Umehara ◽  
Hideyuki Arita ◽  
Ema Yoshioka ◽  
Tomoko Shofuda ◽  
Manabu Kinoshita ◽  
...  

Abstract INTRODUCTION Recent studies have reported that NFKBIA deletion (dNFKBIA) was potentially associated with worse prognosis in glioblastoma (GBM) patients. However, no consensus has been reached to its universal prognostic value. Here, we investigated the survival impact of dNFKBIA using two primary IDH wild-type GBM cohorts: an original Japanese cohort and a dataset from The Cancer Genome Atlas (TCGA). Additionally, prognostic impact of a combination of NFKBIA copy number and MGMT methylation status was evaluated. METHOD The Japanese cohort was collected from cases registered in Kansai Molecular Diagnosis Network for CNS tumors (KNBTG). The survival impact of dNFKBIA and/or unmethylated MGMT (uMGMT) were analyzed for 212 KNBTG cases and 265 TCGA cases. The hazard ratio (HR) and p-value were computed using Cox regression analysis. RESULTS dNFKBIA was less frequently observed in KNBTG (47 cases, 22.2%) than in TCGA (84 cases, 31.7%). dNFKBIA was associated with unfavorable prognosis in KNBTG (HR 1.52, p = 0.031), while this was not validated in TCGA (HR 1.14, p=0.406). uMGMT was a common adverse prognostic factor in KNBGT (HR 1.72, p = 0.001) and TCGA (HR 1.50, p = 0.008) cohort. When stratified by NFKBIA status, uMGMT was also associated with shorter survival in NFKBIA deleted cases both in KNBTG (HR 1.87, p = 0.002) and TCGA (HR 1.59, p = 0.014). On the other hand, MGMT status was not significantly associated with prognosis in NFKBIA intact cases in either KNBTG (HR 1.45, p = 0.279) or TCGA (HR 1.55, p = 0.131). DISCUSSION Although the prognostic value of dNFKBIA in IDH wild-type GBM patients was not validated in TCGA cohort, our results indicated that the prognostication based on MGMT methylation was potentially interacted by NFKBIA status.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi143-vi144
Author(s):  
Thidathip Wongsurawat ◽  
Piroon Jejaroenpun ◽  
Annick DeLoose ◽  
David Ussery ◽  
Duah Alkam ◽  
...  

Abstract Molecular classification of diffuse glioma enables more-precise diagnosis, prognosis, and treatment decisions. Currently, combination of two molecular markers, isocitrate dehydrogenase 1 and 2 (IDH1/ IDH2) gene mutation information and O6-Methylguanine-DNA-methyltranferase (MGMT) methylation status, are the main prognostic biomarkers of newly diagnosed diffuse gliomas. Furthermore, an accurate interpretation of MGMT-promoter methylation status is essential to determining which patients benefit from temozolomide (TMZ) therapy. The presence of an IDH mutation can be easily tested by PCR or next generation sequencing. However, there remains controversy with the identification of MGMT-promoter methylation status since there exists variable degrees of methylation and no clear consensus on cutoff values for “methylated” or “unmethylated” have been defined. To be best suited for routine clinical setting and research use, the optimal test should be reproducible, readily available, and timely. Therefore, we explored the feasibility of single-molecule nanopore third generation sequencing technology to comprehensively assess both mutation and methylation status simultaneously. This technology allows methylation detection directly from the native DNA sequence without requiring bisulfite treatment which reduces processing time. To specifically study IDH1, IDH2, and MGMT-promoter loci, we combined the CRISPR-Cas9 system to cut desired DNA fragments in a non–amplification dependent fashion. In addition, a data analysis pipeline was developed to quantitatively detect methylation. We applied our approach on human DNA controls, glioma cell lines and 4 patient brain tumor samples and were enabled to assess mutation and methylation status of targeted loci within 1.5 days. The promise of CRISPR-Cas9-targeted nanopore sequencing in accelerating and improving the molecular diagnostics of diffuse glioma will be illustrated in this meeting. These efforts are in line with improving precision medicine and can be applied to all cancer types.


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