For adults with glioblastoma undergoing treatment with temozolomide, how do methods of assessing O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status compare for predicting overall survival?

2021 ◽  
Author(s):  
Jane Burch ◽  
Sera Tort
2017 ◽  
Vol 20 (5) ◽  
pp. 642-654 ◽  
Author(s):  
Jian Teng ◽  
Seyedali Hejazi ◽  
Lotte Hiddingh ◽  
Litia Carvalho ◽  
Mark C de Gooijer ◽  
...  

Abstract Background Glioblastoma (GBM) is the most common and most aggressive primary malignant brain tumor. Standard-of-care treatment involves maximal surgical resection of the tumor followed by radiation and chemotherapy (temozolomide [TMZ]). The 5-year survival rate of patients with GBM is <10%, a colossal failure that has been partially attributed to intrinsic and/or acquired resistance to TMZ through O6-methylguanine DNA methyltransferase (MGMT) promoter methylation status in the tumor. Methods A drug screening aimed at evaluating the potential recycling and repurposing of known drugs was conducted in TMZ-resistant GBM cell lines and primary cultures of newly diagnosed GBM with different MGMT promoter methylation status, phenotypic/genotypic background and subtype, and validated with sphere formation, cell migration assays, and quantitative invasive orthotopic in vivo models. Results We identified hydroxyurea (HU) to synergize with TMZ in GBM cells in culture and in vivo, irrespective of MGMT promoter methylation status, subtype, and/or stemness. HU acts specifically on the S-phase of the cell cycle by inhibiting the M2 unit of enzyme ribonucleotide reductase. Knockdown of this enzyme using RNA interference and other known chemical inhibitors exerted a similar effect to HU in combination with TMZ both in culture and in vivo. Conclusions We demonstrate preclinical efficacy of repurposing hydroxyurea in combination with TMZ for adjuvant GBM therapy. This combination benefit is of direct clinical interest given the extensive use of TMZ and the associated problems with TMZ-related resistance and treatment failure.


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. ii135-ii135
Author(s):  
Alyssa Strohbusch ◽  
Heather Pound ◽  
Patrick Regis ◽  
Robert Cavaliere

Abstract BACKGROUND Despite the growing body of evidence demonstrating an increased clinical benefit of alkylating agents in glioblastoma patients with O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation, little is known regarding the effect of MGMT status on toxicity. The purpose of this investigation is to provide insight into the potential association between MGMT promoter methylation and the development of Grade 3/4 hematologic toxicities in patients receiving temozolomide. METHODS A total of 63 patients with documented glioblastoma or anaplastic astrocytoma diagnoses were evaluated retrospectively. A chi-square test of independence was utilized to evaluate the incidence of hematologic toxicities and patient overall survival was determined by univariate analysis estimated through use of Kaplan-Meier curves. Relative frequencies of treatment discontinuation secondary to myelosuppression were also compared. RESULTS At the time of study completion, 71.4% of patients with MGMT promoter hypermethylation had survived compared with 50% of patients with hypomethylation (HR 0.86; 95% CI 0.71 to 1.05; P>0.05). The percentage of patients who experienced Grade 3/4 hematologic toxicities during concurrent treatment was 20% and 5.1% within the hypermethylated and hypomethylated groups, respectively, and 26.7% and 17.9% throughout standard therapy. While a statistical difference was not found between the cumulative incidences of Grade 3/4 hematologic toxicity events throughout both phases of treatment, a statistical difference was noted in the incidence of Grade 4 occurrences with ten events occurring in the hypermethylated group and zero in those with hypomethylated promoter regions (P< 0.01). Furthermore, use of temozolomide in hypermethylated patients resulted in fewer completed cycles of standard therapy and higher rates of treatment delays and drug discontinuation. CONCLUSIONS This study showed marked differences in the frequency of temozolomide-induced hematologic toxicities and treatment discontinuation based on tumor MGMT promoter methylation status. Further research is warranted in larger patient populations to both validate and determine the clinical significance of these findings.


2006 ◽  
Vol 24 (29) ◽  
pp. 4746-4753 ◽  
Author(s):  
Alba A. Brandes ◽  
Alicia Tosoni ◽  
Giovanna Cavallo ◽  
Michele Reni ◽  
Enrico Franceschi ◽  
...  

Purpose To date, no data are available on the relationship between 1p/19q deletions and the response to temozolomide (TMZ) in primary anaplastic oligodendroglioma (AO) and anaplastic oligoastrocytoma (AOA) recurrent after surgery and standard radiotherapy. The aim of this study was to evaluate correlations between 1p/19q deletions, O6-methylguanine DNA methyltransferase (MGMT) promoter methylation, and response rate to TMZ in this setting. Patients and Methods From June 2000 to February 2005, 67 patients were enrolled; 39 patients (58%) had AO and 28 patients (42%) had AOA. All patients received 150 to 200 mg/m2 of TMZ every 28 days. Chromosome 1p and 19q deletions were detected by fluorescence in situ hybridization and MGMT promoter methylation was analyzed using methylation specific polymerase chain reaction. Results The overall response rate was 46.3% (17 complete responses and 14 partial responses). The response rate was higher in patients with AO than in those with AOA (61.5% v 25%, P = .003). Combined 1p/19q allelic loss was found in 32 patients (47.8%), while MGMT methylation occurred in 37 (68.5%) of 54 assessable patients. 1p/19q loss was significantly correlated with response rate (P = .04), time-to-progression (P = .003), and overall survival (P = .0001). Despite the significant concordance found between MGMT promoter methylation and 1p/19q deletions (P = .02), MGMT promoter methylation showed only a borderline correlation with overall survival (P = .09). Conclusion TMZ is active in anaplastic oligodendroglial tumors treated at first recurrence. In this setting, 1p/19q allelic loss is an important predictive and prognostic factor. Further studies on MGMT promoter methylation should be performed in randomized trials to test its correlation with survival.


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