Meta-Analysis of Standard Temozolomide versus Extended Adjuvant Temozolomide following concurrent Radiochemotherapy in newly-diagnosed Glioblastoma (MASTER-G)

Review question / Objective: To assess the safety and efficacy of extended adjuvant temozolomide compared to standard adjuvant temozolomide after concurrent radiochemotherapy in patients with newly-diagnosed glioblastoma. Condition being studied: Newly-diagnosed glioblastoma. Eligibility criteria: Prospective clinical trials randomly assigning patients to extended (>6-cycles) adjuvant TMZ (experimental arm) or standard (6-cycles) adjuvant TMZ will be included. Randomization in an individual study may have been done upfront before concurrent phase (RT/TMZ), after completion of concurrent RT/TMZ and before starting adjuvant phase, or after completion of standard adjuvant TMZ (6-cycles). Emulated RCTs, quasi-randomized trials, propensity matched analyses, non-randomized comparative studies, or observational studies will not be considered in this review.

Accelerated hyper-versus normofractionated radiochemotherapy with temozolomide in patients with glioblastoma: a multicenter retrospective analysis

Background and purpose The standard treatment of glioblastoma patients consists of surgery followed by normofractionated radiotherapy (NFRT) with concomitant and adjuvant temozolomide chemotherapy. Whether accelerated hyperfractionated radiotherapy (HFRT) yields comparable results to NFRT in combination with temozolomide has only sparsely been investigated. The objective of this study was to compare NFRT with HFRT in a multicenter analysis. Materials and methods A total of 484 glioblastoma patients from four centers were retrospectively pooled and analyzed. Three-hundred-ten and 174 patients had been treated with NFRT (30 × 1.8 Gy or 30 × 2 Gy) and HFRT (37 × 1.6 Gy or 30 × 1.8 Gy twice/day), respectively. The primary outcome of interest was overall survival (OS) which was correlated with patient-, tumor- and treatment-related variables via univariable and multivariable Cox frailty models. For multivariable modeling, missing covariates were imputed using multiple imputation by chained equations, and a sensitivity analysis was performed on the complete-cases-only dataset. Results After a median follow-up of 15.7 months (range 0.8–88.6 months), median OS was 16.9 months (15.0–18.7 months) in the NFRT group and 14.9 months (13.2–17.3 months) in the HFRT group (p = 0.26). In multivariable frailty regression, better performance status, gross-total versus not gross-total resection, MGMT hypermethylation, IDH mutation, smaller planning target volume and salvage therapy were significantly associated with longer OS (all p < 0.01). Treatment differences (HFRT versus NFRT) had no significant effect on OS in either univariable or multivariable analysis. Conclusions Since HFRT with temozolomide was not associated with worse OS, we assume HFRT to be a potential option for patients wishing to shorten their treatment time.

Pediatric glioblastoma treated with concurrent radiotherapy and adjuvant Temozolomide: A case study of the treatment of pediatric GBM by the technique of volumetric modulated arc therapy

Introduction: Glioblastoma in children (pGBM) occurs somewhat less frequently than in adults. Pediatric pGBMs have a different molecular profile than GBM for adults. The aim of the presentation of this case is the possibility of the effectiveness of the GBM radiation method and the evaluation of magnetic resonance imaging, and the monitoring of the treatment outcome of the patient.Material and methods: The case study is of the retrospective-prospective type. Medical documentation, magnetic resonance imaging, and chronologically monitored evaluation of the findings from November 2018 to August 2021 were used to present the study. The postoperative course was analyzed, as well as the effect of concurrent chemoradiotherapy, VMAT radiotherapy and adjuvant chemotherapy with Temozolomide in a patient aged 4 years and 6 months, comparing treatment outcome with median and overall survival in glioblastoma.Results: The pediatric patient after being diagnosed with high-grade glioma in 2018 is so far in very good general condition, without signs of physical and psycho-social defects, which compared to the scientifically proven median of survival indicates a good therapeutic effect. Volumetrically modulated arc radiotherapy with the use of modern IGRT verification techniques and with the use of chemotherapy with Temozoloimod, has proven to be a still effective oncological method treatment of GBM. For the final outcome of the disease and the effect of therapeutic modalities, the patient's condition and evaluation of magnetic resonance imaging will be monitored. The result supports further research into this therapeutic regimen.Conclusion: Glioblastoma is a very aggressive tumor, which occurs somewhat less frequently in the pediatric population than in adults, but is a very fatal disease. Surgical resection followed by concurrent chemoradiotherapy, with adjuvant Temozolomide is still the method of choice in the treatment of glioblastoma.

A Systematic Review and Meta-Analysis on the Number of Adjuvant Temozolomide Cycles in Newly Diagnosed Glioblastoma

BackgroundIn newly diagnosed glioblastoma, radiation with concurrent and adjuvant (six cycles) temozolomide (TMZ) is the established standard of postsurgical care. However, the benefit of extending adjuvant TMZ therapy beyond six cycles has remained unknown.MethodsWe searched PubMed, Web of Science, Scopus, and Embase up to October 1, 2021. The search keywords were “glioblastoma,” “adjuvant chemotherapy,” and their synonyms. The data of randomized clinical trials were extracted and included in this meta-analysis if they had reported patients’ median overall survival (OS) or median progression-free survival (PFS). The standard and extended chemotherapy regimens were considered as adjuvant TMZ up to six cycles and beyond six cycles (up to a total of 12 cycles), respectively. The median OS and median PFS were pooled and compared.ResultsFour studies consisting of 882 patients (461 patients for the standard chemotherapy group and 421 patients for the extended chemotherapy group) were included in this meta-analysis. The extended TMZ regimen was associated with a nonsignificant improvement in PFS [12.0 months (95% CI 9.0 to 15.0) vs. 10.0 months (95% CI 7.0 to 12.0), P = 0.27] without corresponding improvement in OS [23.0 months (95% CI 19.0 to 27.0) and 24.0 months (95% CI 20.0 to 28.0), P = 0.73].ConclusionsIn newly diagnosed glioblastoma, continuing adjuvant TMZ beyond six cycles did not shown an increase neither in PFS nor OS.

A Simple Preoperative Blood Count to Stratify Prognosis in Isocitrate Dehydrogenase-Wildtype Glioblastoma Patients Treated with Radiotherapy plus Concomitant and Adjuvant Temozolomide

Purpose: The survival times of glioblastoma (GB) patients after the standard therapy including safe maximal resection followed by radiotherapy plus concomitant and adjuvant temozolomide are heterogeneous. In order to define a simple, reliable method for predicting whether patients with isocitrate dehydrogenase (IDH)-wildtype GB treated with the standard therapy will be short- or long-term survivors, we analyzed the correlation of preoperative blood counts and their combined forms with progression-free survival (PFS) and overall survival (OS) in these patients. Methods: Eighty-five patients with primary IDH-wildtype GB treated with the standard therapy between 2012 and 2019 were analyzed retrospectively. Cox proportional hazards models and Kaplan–Meier analysis were used to investigate the survival function of preoperative hematological parameters. Results: Preoperative high neutrophil-to-lymphocyte ratio (NLR, >2.42), high platelet count (>2.36 × 109/L), and low red blood cell (RBC) count (≤4.59 × 1012/L) were independent prognostic factors for poorer OS (p = 0.030, p = 0.030, and p = 0.004, respectively). Moreover, a high NLR was an independent prognostic factor for shorter PFS (p = 0.010). We also found that, like NLR, preoperative high derived NLR (dNLR, >1.89) was of poor prognostic value for both PFS (p = 0.002) and OS (p = 0.033). A significant correlation was observed between NLR and dNLR (r = 0.88, p < 0.001), which had a similar prognostic power for OS (NLR: AUC = 0.58; 95% CI: [0.48; 0.68]; dNLR: AUC = 0.62; 95% CI: [0.51; 0.72]). Two scores, one based on preoperative platelet and RBC counts plus NLR and the other on preoperative platelet and RBC counts plus dNLR, were found to be independent prognostic factors for PFS (p = 0.006 and p = 0.002, respectively) and OS (p < 0.001 for both scores). Conclusion: Cheap, routinely ordered, preoperative assessments of blood markers, such as NLR, dNLR, RBC, and platelet counts, can predict the survival outcomes of patients with IDH-wildtype GB treated with the standard therapy.

Accelerated Hyper-Versus Normofractionated Radiochemotherapy with Temozolomide in Patients with Glioblastoma: A Multicenter Retrospective Analysis.

Background and purpose The standard treatment of glioblastoma (GB) patients consists of surgery followed by normofractionated radiotherapy (NFRT) with concomitant and adjuvant temozolomide chemotherapy. Whether accelerated hyperfractionated radiotherapy (HFRT) yields comparable results to NFRT in combination with temozolomide has only sparsely been investigated. The objective of this study was to compare NFRT with HFRT in a multicenter analysis. Materials and methods A total of 484 GB patients from four centers were retrospectively pooled and analyzed. 310 and 174 patients had been treated with NFRT (30×1.8Gy or 30×2Gy) and HFRT (37×1.6Gy or 30×1.8Gy twice/day), respectively. The primary outcome of interest was overall survival (OS) which was correlated with patient-, tumor- and treatment-related variables via univariable and multivariable Cox frailty models. For multivariable modeling, missing covariates were imputed using multiple imputation by chained equations, and a sensitivity analysis was performed on the complete-cases-only dataset. Results After a median follow-up of 15.7 months (range 0.8-88.6 months), median OS was 16.9 months (15.0-18.7 months) in the NFRT group and 14.9 months (13.2-17.3 months) in the HFRT group (p=0.26). In multivariable frailty regression, better performance status, complete versus not complete resection, MGMT hypermethylation, IDH mutation, smaller planning target volume, no steroid administration, and salvage therapy were significantly associated with longer OS (all p<0.01). Treatment differences (HFRT versus NFRT) had no significant effect on OS in either univariable or multivariable analysis. Conclusions This analysis suggests that HFRT and temozolomide is a safe option for patients wishing to shorten their treatment time and does not affect OS.

PATH-27. MGMT PROMOTER STATUS IN IDH1/2 MUTANT ANAPLASTIC ASTROCYTOMA PATIENTS ASSESSED BY DNA METHYLATION PROFILING AND QMS-PCR: A REPORT FROM THE EORTC BRAIN TUMOR GROUP

BACKGROUND Temozolomide efficacy in high-grade glioma is related to MGMTp methylation. We compared the prognostic and predictive effect of MGMTp between DNA methylation profiling (MGMT-STP27 model) and qMS-PCR in IDH1/2mt anaplastic astrocytoma patients. METHODS The 2x2 factorial design phase III CATNON trial randomized 751 adult patients with newly diagnosed 1p/19q non-codeleted anaplastic glioma to 59.4Gy radiotherapy, radiotherapy with concurrent temozolomide, radiotherapy with 12 cycles of adjuvant temozolomide, or radiotherapy with concurrent and adjuvant temozolomide. MGMTp methylation status was assessed with the MGMT-STP27 model using 850k EPIC data, and qMS-PCR. IDH1/2 mutation status was determined with next-generation sequencing. OS was measured from randomization date. RESULTS We identified 444 IDH1/2mt anaplastic astrocytoma patients. MGMTp was methylated in 365/440 patients (83.0%) with MGMT-STP27 data, and 168/361 patients (46.5%) with qMS-PCR data. The agreement between both modalities is 59.9% (Cohen’s Kappa score 0.229). At database lock, 289 patients with MGMT-STP27 data were alive and 236 patients with qMS-PCR data. The median OS of MGMTp methylated glioma patients was 9.1 yrs [95%CI 7.5-not reached] for the MGMT-STP27 model, and not reached [95%CI 9.1-not reached] for qMS-PCR. For MGMTp unmethylated glioma patients, the median OS was 6.9 yrs [95%CI 6.2-not reached] for the MGMT-STP27 model, and 6.8 yrs [95%CI 6.2-9.7] for qMS-PCR. The HR for OS based on MGMTp methylation was 0.88 [95%CI 0.58-1.31] for the MGMT-STP27 model, and 0.72 [95%CI 0.50-1.03]) for qMS-PCR. The HR for OS after radiotherapy with any temozolomide vs radiotherapy alone for the MGMT-STP27 model was 0.53 [95%CI 0.37-0.78] for MGMTp methylated, and 0.54 [95%CI 0.25-1.18] for MGMTp unmethylated glioma patients; and for MS-PCR was 0.34 [95%CI 0.19-0.61] for MGMTp methylated, and 0.53 [95%CI 0.33-0.85] for MGMTp unmethylated glioma patients. CONCLUSION MGMTp methylation, regardless of assay, was neither prognostic nor predictive for outcome to temozolomide in IDH1/2mt anaplastic astrocytoma patients.

NCOG-34. A DESCRIPTIVE ANALYSIS OF GLIOMATOSIS CEREBRI CASES, COMPARED ACCORDING TO IDH STATUS

Gliomatosis cerebri (GC) is a controversial entity no longer recognized as a histopathologic-defined diagnosis, characterized by diffuse, commonly bilateral infiltration of cerebral hemispheres. The purpose of this report is to describe clinical, imaging, patient-reported outcomes (PRO’s) and pathologic characteristics of clinically-defined cases from a large natural history study cohort (N=769). Of 19 patients, 10 male, 16 white, mean age at diagnosis 43 (19-70), seventeen presented as primary GC, while 2 developed GC after treatment. Ten patients were IDH-WT, 7 IDH-M, and 2 IDH undetermined. The majority (7/10) IDH-WT patients presented acutely (5 with seizures), whereas, 3 had a protracted presentation of 2 weeks-3months with 6/10 having enhancing tumors and 8/10 undergoing biopsy only. On histopathologic review, 4 were anaplastic astrocytoma (AA), 3 GBMs, 2 grade II astrocytoma, and 1 histone-mutated glioma. Nearly all (9/10) IDH-WT patients received radiation with concurrent and adjuvant temozolomide. 7/10 IDH-WT patients had a survival of only 1.5yrs or less from diagnosis. Of the 7 IDH-M patients, 4 had protracted presentations of 1 month-5 years. 6/7 had non-enhancing tumors at presentation. 4 had biopsy only and 3 underwent partial resection. 3 were AA, 2 grade II astrocytoma, 1 grade II oligodendroglioma, and 1 grade IV astrocytoma. 3/7 received radiation with concurrent and adjuvant temozolomide, 3/7 chemotherapy alone, and 1 RT alone. All 7 IDH-M patients survived 3+ years from diagnosis (range 3-10+ yrs). Both patients who developed GC later, were IDH-M, with prolonged survival (3.5yrs and the other still alive 10+yrs). PRO's at time of last clinical assessment revealed GC patients to be highly symptomatic with mean overall symptom burden, depression, and anxiety higher than our overall glioma population. GC patients have a varied clinical course mandating further investigation to enable better prognostic definition to refine treatments based on the varying clinical and molecular characteristics.

RADT-18. NEOADJUVANT (PRE RADIOTHERAPY) TEMOZOLOMIDE FOLLOWED BY RADIATION THERAPY WITH CONCURRENT AND ADJUVANT TEMOZOLOMIDE IN GLIOBLASTOMA MULTIFORME

BACKGROUD AND PURPOSE To evaluate the effect of neoadjuvant [pre-radiotherapy(RT)] temozolomide (TMZ) in glioblastoma multiforme (GBM) patients in terms of overall survival(OS) and progression free survival (PFS). MATERIAL AND METHODS Patients with diagnosed GBM are treated with neoadjuvant( pre RT) TMZ followed by concurrent RT-TMZ and adjuvant TMZ. The Kaplan-Meier method is used to estimate OS the differences between groups. RESULTS Twenty five patients are match with inclusion criteria. Age group, Recurvsive partitioning analysis (RPA) class and extent of surgery are found to effect on overall survival but statistically not significant. At end of study, 40 percent patients are alive with 9 months PFS and 11 months OS. CONCLUSION The neo-adjuvant TMZ with concomitant and adjuvant TMZ is feasible and safe which is associated with an encouraging favorable long-term survival with acceptable toxicity.

RTID-04. GLIOTARGET: A DANISH NATIONWIDE PHASE I/II PLATFORM TRIAL FOCUSING ON INDIVIDUALIZED TARGETED TREATMENT FOR NEWLY DIAGNOSED GLIOBLASTOMA PATIENTS BASED ON GENOMIC PROFILING

INTRODUCTION The survival in glioblastoma has been unchanged since 2005. The introduction of targeted treatments, which have improved survival in several cancers has yet to influence the treatment of glioblastoma. In Gliotarget, we will individualize the targeted treatment, and give it in the primary setting alongside standard therapy with the intention to improve the likelihood of effect. METHODS Gliotarget is a biomarker enriched phase I/II platform trial with initially 4 predefined biomarker selected arms, one miscellaneous biomarker arm and one control arm. All patients receive standard therapy with concomitant radiochemotherapy and adjuvant Temozolomide. The experimental treatment is given alongside the adjuvant Temozolomide. Molecular analysis, including Whole Genome Sequencing, is performed on all patients, to identify actionable biomarkers. The miscellaneous arm gathers patients with not previously defined biomarkers upon which the weekly molecular tumor board decides to treat. Gliotarget includes newly diagnosed IDH-wt glioblastoma patients. In addition, to exclude the patients where the inherent poor prognosis might conceal the drug efficacy, the patients must have a 50% probability of being alive 12 months after initial surgery, according to a prognostic model developed in our institution. The sample size is calculated with Simon’s two-stage design using treatment effect at 9-months progression free survival (PFS9). We anticipate 9 patients for stage one and 24 in total, for each arm. Treatment effect is defined as 65% of the patients in an experimental arm reaching PFS9. For the survival analysis, supplementing the control arm data with leveraged external controls taken from our prospectively registered database will decrease the probability of false positive results. CONCLUSION Gliotarget complements the field of ongoing platform trials with its distinctive trial design. The chosen biomarkers and treatments will be presented at the annual meeting. Enrollment is set to open in Q4 2021.