Survival impact of time to initiation of chemoradiotherapy after resection of newly diagnosed glioblastoma

GammaTile® (GT) as a brachytherapy platform for rapidly proliferating glioblastomas: from case series to clinical trials

PURPOSE

Radiation plays a central role in glioblastoma treatment. Logistics related to coordinating clinic visits, radiation planning, and surgical recovery necessitate delay in radiation delivery from the time of diagnosis. Unimpeded tumor growth occurs during this period, and is associated with poor clinical outcome. Here we provide a pilot experience of GammaTile ® (GT), a collagen tile-embedded Cesium-131 (131Cs) brachytherapy platform for such aggressive tumors.

METHODS

We prospectively followed seven consecutive patients (2019-2023) with newly diagnosed (n = 3) or recurrent (n = 4) isocitrate dehydrogenase wild-type glioblastoma that grew > 100% in volume during the 30 days between the time of initial diagnosis/surgery and the radiation planning MRI. These patients underwent re-resection followed by GT placement.

RESULTS

There were no surgical complications. One patient developed right hemiparesis prior to re-resection/GT placement and was discharged to rehabilitation, all others were discharged home-with a median hospital stay of 2 days (range: 1-5 days). There was no 30-day mortality and one 30-day readmission (hydrocephalus, requiring ventriculoperitoneal shunting (14%)). With a median follow-up of 347 days (11.6 months), median progression free survival of ≥ 320 days (10.6 months) was achieved for both newly and recurrent glioblastoma patients. The median overall survival (mOS) was 304 and 347 days (10 and 11.5 mo) for recurrent and newly diagnosed glioblastoma patients, respectively.

CONCLUSION

Our pilot experience suggests that GT offers favorable local control and safety profile for patients afflicted with rapidly proliferating glioblastomas and lay the foundation for future clinical trial design.

The prognosis of gliomas with different molecular subtypes in the era of intensity-modulated radiation therapy (IMRT)

PURPOSE

This study aimed to evaluate the prognosis of glioma patients with different molecular subtypes of who treated with intensity-modulated radiation therapy (IMRT).

METHODS

We collected 45 glioma patients treated in our hospital between January 2017 and December 2020. All enrolled patients received postoperative IMRT and were divided into two groups based on the Isocitrate dehydrogenase (IDH status). Overall survival (OS) and progression-free survival (PFS) were estimated retrospectively.

RESULTS

The median follow-up was 22 months (range 2-108.5 months). The 1-year OS of IDH-mut group and ΙDH-wild group was similar (77.3% vs. 81.5%, p = 0.16). While the 1-year PFS of IDH-mut group was significantly higher than that in ΙDH-wild group (90.4% vs. 39.8%, p = 0.0051). Subgroup analysis revealed that the 1-year PFS of IDH-mut/1p/19q codeletion group and IDH-mut/1p/19q noncodeletion group was significantly higher than in IDH-wild type patients. For patients with IDH-mut/MGMT-methylation, the outcome was no significant difference in OS, but PFS was longer than other subtypes.

CONCLUSION

This retrospective study showed that 1-year PFS of patients with IDH mutated was better than IDH-wild type patients. In subgroups analysis, the outcomes were shown that patients with IDH-mut/ 1p/19q codeletion and patients with IDH-mut/1p/19q noncodeletion had longer 1-year PFS than IDH-wild type patients, but the OS was similar between the subgroups. Patients with IDH-mut/MGMT-methylation had the best prognosis in the whole subgroups. However, these results still need further confirmation of large sample size, prospectively, randomized controlled trails.

Impact of radiotherapy delay following biopsy for patients with unresected glioblastoma

OBJECTIVE

Because of the aggressive nature of glioblastoma, patients with unresected disease are encouraged to begin radiotherapy within approximately 1 month after craniotomy. The aim of this study was to investigate the potential association between time interval from biopsy to radiotherapy with overall survival in patients with unresected glioblastoma.

METHODS

Patients with unresected glioblastoma diagnosed between 2010 and 2014 who received adjuvant radiotherapy and concurrent chemotherapy were identified in the National Cancer Database. Demographic and clinical data were compared using chi-square and Wilcoxon rank-sum tests. Survival was analyzed using the Kaplan-Meier method and Cox proportional hazards regression modeling.

RESULTS

Among 3456 patients with unresected glioblastoma, initiation of radiotherapy within 3 weeks of biopsy was associated with a higher hazard of death compared with later initiation of radiotherapy. After excluding patients who received radiotherapy within 3 weeks of biopsy to minimize the effects of confounders associated with short time intervals from biopsy to radiotherapy, the median interval from biopsy to radiotherapy was 32 days (IQR 27-39 days). Overall, 1782 (66.82%) patients started radiotherapy within 5 weeks of biopsy, and 885 (33.18%) patients started radiotherapy beyond 5 weeks of biopsy. On multivariable analysis, there was no significant difference in overall survival between these two groups (HR 0.96, 95% CI 0.88-1.50; p = 0.374).

CONCLUSIONS

In patients with unresected glioblastoma, a longer time interval from biopsy to radiotherapy does not appear to be associated with worse overall survival. However, external validation of these findings is necessary given that selection bias is a significant limitation of this study.

Impact of timing to initiate adjuvant therapy on survival of elderly glioblastoma patients using the SEER-Medicare and national cancer databases

The optimal time to initiate adjuvant therapy (AT) in elderly patients with glioblastoma (GBM) remains unclear. We investigated the impact of timing to start AT on overall survival (OS) using two national-scale datasets covering elderly GBM populations in the United States. A total of 3159 and 8161 eligible elderly GBM patients were derived from the Surveillance, Epidemiology and End Results (SEER)-Medicare linked dataset (2004-2013) and the National Cancer Database (NCDB) (2004-2014), respectively. The intervals in days from the diagnosis to the initiation of AT were categorized based on two scenarios: Scenario I (quartiles), ≤ 15, 16-26, 27-37, and ≥ 38 days; Scenario II (median), < 27, and ≥ 27 days. The primary outcome was OS. We performed the Kaplan-Meier and Cox proportional hazards regression methods for survival analysis. A sensitivity analysis was performed using Propensity Score Matching (PSM) method to achieve well-balanced characteristics between early-timing and delayed-timing in Scenario II. Improved OS was observed among patients who underwent resection and initiated AT with either a modest delay (27-37 days) or a longer delay (≥ 38 days) compared to those who received AT immediately (≤ 15 days) from both the SEER-Medicare dataset [adjusted hazard ratio (aHR) 0.74, 95% CI 0.64-0.84, P < 0.001; and aHR 0.81, 95% CI 0.71-0.92, P = 0.002] and the NCDB (aHR 0.83, 95% CI 0.74-0.93, P = 0.001; and aHR 0.87, 95% CI 0.77-0.98, P = 0.017). The survival advantage is observed in delayed-timing group as well in Scenario II. For elderly patients who had biopsy only, improved OS was only detected in a longer delay (Scenario I: ≥ 38 days vs. ≤ 15 days) or the delayed-timing group (Scenario II: ≥ 27 days vs. < 27 days) in the NCDB while no survival difference was seen in SEER-Medicare population. For the best timing to start AT in elderly GBM patients, superior survivals were observed among those who had craniotomy and initiated AT with a modest (27-37 days) or longer delays (≥ 38 days) following diagnosis using both the SEER-Medicare and NCDB datasets (Scenario I). Such survival advantage was confirmed when categorizing delayed-timing vs. early-timing with the cut-off at 27 day in both datasets (Scenario II). The increased likelihood of receiving delayed AT (≥ 27 days) was significantly associated with tumor resection (STR/GTR), years of diagnosis after 2006, African American and Hispanics races, treatments at academic facilities, and being referred. There is no difference in timing of AT on survival among elderly GBM patients who had biopsy in the SEER-Medicare dataset. In conclusion, initiating AT with a modest delay (27-37 days) or a longer delay (≥ 38 days) after craniotomy may be the preferred timing in the elderly GBM population.

Association of perioperative adverse events with subsequent therapy and overall survival in patients with WHO grade III and IV gliomas

Background

Maximum safe resection followed by chemoradiotherapy as current standard of care for WHO grade III and IV gliomas can be influenced by the occurrence of perioperative adverse events (AE). The aim of this study was to determine the association of AE with the timing and choice of subsequent treatments as well as with overall survival (OS).

Methods

Prospectively collected data of 283 adult patients undergoing surgery for WHO grade III and IV gliomas at the University Hospital Zurich between January 2013 and June 2017 were analyzed. We assessed basic patient characteristics, KPS, extent of resection, and WHO grade, and we classified AE as well as modality, timing of subsequent treatment (delay, interruption, or non-initiation), and OS.

Results

In 117 patients (41%), an AE was documented between surgery and the 3-month follow-up. There was a significant association of AE with an increased time to initiation of subsequent therapy (p = 0.005) and a higher rate of interruption (p < 0.001) or non-initiation (p < 0.001). AE grades correlated with time to initiation of subsequent therapy (p = 0.038). AEs were associated with shorter OS in univariate analysis (p < 0.001).

Conclusion

AEs are associated with delayed and/or altered subsequent therapy and can therefore limit OS. These data emphasize the importance of safety within the maximum-safe-resection concept.

Impact of Rural vs. Urban Residence on Survival Rates of Patients with Glioblastoma: A Tertiary Care Center Experience

Purpose: Although the association between residential location and survival in patients with different cancer types has been established, the conclusions are contentious, and the underlying mechanisms remain unknown. Here, we reviewed the impact of residence on the survival of patients with glioblastoma (GBM). Methods: We conducted a retrospective study to compare the impact of rural and urban residence on the survival rates of patients with GBM diagnosed in Riyadh City and outside Riyadh. All patients in this study were treated in a tertiary care hospital, and their survival rates were analyzed in relation to their residence and other related factors, namely radiotherapy timing. Results: Overall, 125 patients were included: 61 from Riyadh City and 64 from outside. The majority of patients in both groups were aged >50 years (p = 0.814). There was no statistically significant difference between the groups in the Eastern Cooperative Oncology Group Performance Status (p = 0.430), seizure (p = 0.858), or initiation timing of radiotherapy (p = 0.781). Furthermore, the median survival rate in the Riyadh group versus the other group was 14.4 months and 12.2 months, respectively, with no statistical significance (p = 0.187). Conclusions: Our study showed that residential location had no significant effect on GBM prognosis. However, further studies with a larger sample size are required to delineate the other factors of referral within the healthcare system to facilitate the management of these patients within a specific timeframe.

GNG12 as A Novel Molecular Marker for the Diagnosis and Treatment of Glioma

Purpose

GNG12 influences a variety of tumors; however, its relationship with glioma remains unclear. The aim of this study was to comprehensively investigate the relationship between GNG12 and the clinical characteristics and prognosis of glioma patients and reveal the mechanisms causing the malignant process of GNG12.

Materials and Methods

We obtained information on clinical samples from multiple databases. The expression level of GNG12 was validated using a RT-qPCR and IHC. KM curves were used to assess the correlation between the GNG12 expression and OS of glioma patients. An ROC curve was drawn to assess the predictive performance of GNG12. Univariate and multivariate Cox analyses were performed to analyze the factors affecting the prognosis of patients with glioma. GSEA and TIMER databases were used to estimate the relationship between GNG12 expression, possible molecular mechanisms, and immune cell infiltration. CMap analysis was used to screen candidate drugs for glioma. Subsequent in vitro experiments were used to validate the proliferation and migration of glioma cells and to explore the potential mechanisms by which GNG12 causes poor prognosis in gliomas.

Results

GNG12 was overexpressed in glioma patients and GNG12 expression level correlated closely with clinical features, including age and histological type, etc. Subsequently, the K-M survival analysis indicated that the expression level of GNG12 was relevant to the prognosis of glioma, and the ROC curve implied that GNG12 can predict glioma stability. Univariate and multivariate analyses showed that GNG12 represents a risk factor for glioma occurrence. GNG12 expression is closely associated with some immune cells. Additionally, several in vitro experiments demonstrated that down-regulation of GNG12 expression can inhibits the proliferation and migration capacity of glioma cells. Ultimately, the results for the GSEA and WB experiments revealed that GNG12 may promote the malignant progression of gliomas by regulating the cell adhesion molecule cell signaling pathway.

Conclusion

In this study, we identified GNG12 as a novel oncogene elevated in gliomas. Reducing GNG12 expression inhibits the proliferation and migration of glioma cells. In summary, GNG12 can be used as a novel biomarker for the early diagnosis of human gliomas and as a potential therapeutic target.

Timing of radiotherapy in glioblastoma based on IMRT and STUPP chemo-radiation: may be no need to rush

OBJECTIVE

To investigate the effect of surgery to radiotherapy interval (SRI) on the prognosis of patients with isocitrate dehydrogenase (IDH) wild-type glioblastoma.

METHODS

Retrospective analysis of the relationship between SRI and prognosis of patients with IDH wild-type glioblastoma who received postoperative intensity modulated radiotherapy (IMRT) in our center from July 2013 to July 2019. The patients were divided into SRI ≤ 42 days (regular group) and SRI > 42 days (delay group). Kaplan-Meier univariate analysis and Cox proportional hazard model were used to analyze whether SRI was an independent factor influencing the prognosis.

RESULTS

A total of 102 IDH wild-type glioblastoma were enrolled. Median follow-up was 35.9 months. The 1-, 2- and 3-year OS of "regular group" were 69.5%, 34.8%, 19.1%, and "delay group" were 69.8%, 26.1% and 13.4% respectively. Multivariate analysis showed that extent of resection (p = 0.041) was an independent prognostic factor for OS. SRI (p = 0.347), gender (p = 0.159), age (p = 0. 921), maximum diameter (p = 0.637) MGMT promoter methylation status (P = 0.630) and ki-67 expression (P = 0.974) had no effect on OS. Univariate analysis (p = 0.483) and multivariate analysis (p = 0.373) also showed that SRI had no effect on OS in glioblastoma who received gross total resection.

CONCLUSION

Appropriate extension in SRI has no negative effect on the OS of IDH wild-type glioblastoma. It is suggested that radiotherapy should be started after a good recovery from surgery. This conclusion needs further confirmed by long-term follow-up of a large sample.

Glioma targeted therapy: insight into future of molecular approaches

Gliomas are the common type of brain tumors originating from glial cells. Epidemiologically, gliomas occur among all ages, more often seen in adults, which males are more susceptible than females. According to the fifth edition of the WHO Classification of Tumors of the Central Nervous System (WHO CNS5), standard of care and prognosis of gliomas can be dramatically different. Generally, circumscribed gliomas are usually benign and recommended to early complete resection, with chemotherapy if necessary. Diffuse gliomas and other high-grade gliomas according to their molecule subtype are slightly intractable, with necessity of chemotherapy. However, for glioblastoma, feasible resection followed by radiotherapy plus temozolomide chemotherapy define the current standard of care. Here, we discuss novel feasible or potential targets for treatment of gliomas, especially IDH-wild type glioblastoma. Classic targets such as the p53 and retinoblastoma (RB) pathway and epidermal growth factor receptor (EGFR) gene alteration have met failure due to complex regulatory network. There is ever-increasing interest in immunotherapy (immune checkpoint molecule, tumor associated macrophage, dendritic cell vaccine, CAR-T), tumor microenvironment, and combination of several efficacious methods. With many targeted therapy options emerging, biomarkers guiding the prescription of a particular targeted therapy are also attractive. More pre-clinical and clinical trials are urgently needed to explore and evaluate the feasibility of targeted therapy with the corresponding biomarkers for effective personalized treatment options.

Effect of long-term adjuvant temozolomide chemotherapy on primary glioblastoma patient survival

Objective

Glioblastoma multiforme (GBM) is the most common primary malignant central nervous system (CNS) tumor. The Stupp regimen is the standard treatment, although the optimal number of temozolomide (TMZ) treatment cycles remains controversial. We compared the effects of standard 6 cycles versus > 6 cycles of TMZ chemotherapy post-surgery with concurrent chemoradiotherapy on primary GBM patient survival.

Patients and methods

We performed a single center retrospective study of GBM patients that underwent total resection, concurrent chemoradiotherapy, and at least 6 cycles of adjuvant TMZ chemotherapy from June 2011 to August 2018. Patients were divided into 2 groups based on adjuvant TMZ treatment plan: Group A(n = 27): standard 6-cycle adjuvant TMZ therapy and Group B(n = 26): > 6 cycles of adjuvant TMZ therapy. Primary endpoints were progression-free survival (PFS) and overall survival (OS). Continuous variables were analyzed by ANOVA, and the Kaplan-Meier method was used to evaluate PFS and OS. Univariate and multivariate COX analyses determined correlation between survival rates and covariates. We used The Mini Mental State Examination (MMSE) and Karnofsky Performance Status (KPS) to assess patients’ neurocognitive function and quality of life.

Results

After follow-up, median PFS was 15 months in in Group A (95%CI 9.5–20.5) and 20.1 months in Group B (95%CI 15.9–24.4). Group A median OS was 19.4 months (95%CI 15.5–23.2), compared to 25.6 months in Group B (95%CI 20.4–30.8). The 2-year survival rate of Groups A and B was 36% was 66%, respectively (P = 0.02). and 5-year survival was 7% in both. Multivariate COX regression analysis showed association between patient PFS and long-period adjuvant chemotherapy, but not OS. There were no significant difference in disability or quality of life during treatment with Stupp protocol, but differences in MMSE and KPS were in favour of the Groups B after year 1 of the treatment (P < 0.05).

Conclusions

Long-term adjuvant TMZ chemotherapy was beneficial for PFS and 2-year survival rate in GBM patients, and improved their quality of life contemporarily. But OS was not significantly improved.

The Role of Delayed Radiotherapy Initiation in Patients with Newly Diagnosed Glioblastoma with Residual Tumor Mass

OBJECTIVE

 Treatment for newly diagnosed isocitrate dehydrogenase (IDH) wild-type glioblastoma (GBM) includes maximum safe resection, followed by adjuvant radio(chemo)therapy (RCx) with temozolomide. There is evidence that it is safe for GBM patients to prolong time to irradiation over 4 weeks after surgery. This study aimed at evaluating whether this applies to GBM patients with different levels of residual tumor volume (RV).

METHODS

 Medical records of all patients with newly diagnosed GBM at our department between 2014 and 2018 were reviewed. Patients who received adjuvant radio (chemo) therapy, aged older than 18 years, and with adequate perioperative imaging were included. Initial and residual tumor volumes were determined. Time to irradiation was dichotomized into two groups (≤28 and >28 days). Univariate analysis with Kaplan-Meier estimate and log-rank test was performed. Survival prediction and multivariate analysis were performed employing Cox proportional hazard regression.

RESULTS

 One hundred and twelve patients were included. Adjuvant treatment regimen, extent of resection, residual tumor volume, and O⁶-methylguanine DNA methyltransferase (MGMT) promoter methylation were statistically significant factors for overall survival (OS). Time to irradiation had no impact on progression-free survival (p = 0.946) or OS (p = 0.757). When stratified for different thresholds of residual tumor volume, survival predication via Cox regression favored time to irradiation below 28 days for patients with residual tumor volume above 2 mL, but statistical significance was not reached.

CONCLUSION

 Time to irradiation had no significant influence on OS of the entire cohort. Nevertheless, a statistically nonsignificant survival prolongation could be observed in patients with residual tumor volume > 2 mL when admitted to radiotherapy within 28 days after surgery.

The survival impact of significant delays between surgery and radiochemotherapy in glioblastoma patients: A retrospective analysis from a large tertiary center

The optimal timing of adjuvant radiochemotherapy (RCT) in glioblastoma (GBM) patients remains unknown and the paradigm of 'the sooner, the better' has been challenged by many recent publications. In this study, we present unique data on the outcomes of patients with significant treatment delays. The study group consisted of 346 GBM patients (median age 56.8 years) who received surgical treatment (total or subtotal resection) and then underwent adjuvant concurrent RCT at one institution. The main endpoint was overall survival (OS). The Univariate and multivariate Cox Proportional-Hazard Model, log-rank test, and Kaplan-Meier method were used for the analysis. The median OS was 18.7 months and the 5-year overall survival was 8.5%. The median time interval from surgery to RCT was 9.8 weeks. The Cox regression showed that the time interval had no statistically significant impact on OS both in uni- and multivariate analysis. The explorative analysis suggested a positive trend for improved survival for patients in the 1st quartile of the time interval, especially for patients with residual disease or local recurrence prior to RCT, However, considering the 6.9 weeks median interval in the 1st quartile, this subgroup should still be regarded as 'moderate delay' compared with other literature data. The results indicate that the time interval is not a clear prognostic factor in the treatment of GBM. Prospective trials are highly warranted, as data suggest that moderate delays in the initiation of adjuvant treatment might be associated with survival benefit.

Prognostic value of test(s) for O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation for predicting overall survival in people with glioblastoma treated with temozolomide

BACKGROUND

Glioblastoma is an aggressive form of brain cancer. Approximately five in 100 people with glioblastoma survive for five years past diagnosis. Glioblastomas that have a particular modification to their DNA (called methylation) in a particular region (the O6-methylguanine-DNA methyltransferase (MGMT) promoter) respond better to treatment with chemotherapy using a drug called temozolomide.

OBJECTIVES

To determine which method for assessing MGMT methylation status best predicts overall survival in people diagnosed with glioblastoma who are treated with temozolomide.

SEARCH METHODS

We searched MEDLINE, Embase, BIOSIS, Web of Science Conference Proceedings Citation Index to December 2018, and examined reference lists. For economic evaluation studies, we additionally searched NHS Economic Evaluation Database (EED) up to December 2014.

SELECTION CRITERIA

Eligible studies were longitudinal (cohort) studies of adults with diagnosed glioblastoma treated with temozolomide with/without radiotherapy/surgery. Studies had to have related MGMT status in tumour tissue (assessed by one or more method) with overall survival and presented results as hazard ratios or with sufficient information (e.g. Kaplan-Meier curves) for us to estimate hazard ratios. We focused mainly on studies comparing two or more methods, and listed brief details of articles that examined a single method of measuring MGMT promoter methylation. We also sought economic evaluations conducted alongside trials, modelling studies and cost analysis.

DATA COLLECTION AND ANALYSIS

Two review authors independently undertook all steps of the identification and data extraction process for multiple-method studies. We assessed risk of bias and applicability using our own modified and extended version of the QUality In Prognosis Studies (QUIPS) tool. We compared different techniques, exact promoter regions (5'-cytosine-phosphate-guanine-3' (CpG) sites) and thresholds for interpretation within studies by examining hazard ratios. We performed meta-analyses for comparisons of the three most commonly examined methods (immunohistochemistry (IHC), methylation-specific polymerase chain reaction (MSP) and pyrosequencing (PSQ)), with ratios of hazard ratios (RHR), using an imputed value of the correlation between results based on the same individuals.

MAIN RESULTS

We included 32 independent cohorts involving 3474 people that compared two or more methods. We found evidence that MSP (CpG sites 76 to 80 and 84 to 87) is more prognostic than IHC for MGMT protein at varying thresholds (RHR 1.31, 95% confidence interval (CI) 1.01 to 1.71). We also found evidence that PSQ is more prognostic than IHC for MGMT protein at various thresholds (RHR 1.36, 95% CI 1.01 to 1.84). The data suggest that PSQ (mainly at CpG sites 74 to 78, using various thresholds) is slightly more prognostic than MSP at sites 76 to 80 and 84 to 87 (RHR 1.14, 95% CI 0.87 to 1.48). Many variants of PSQ have been compared, although we did not see any strong and consistent messages from the results. Targeting multiple CpG sites is likely to be more prognostic than targeting just one. In addition, we identified and summarised 190 articles describing a single method for measuring MGMT promoter methylation status.

AUTHORS' CONCLUSIONS

PSQ and MSP appear more prognostic for overall survival than IHC. Strong evidence is not available to draw conclusions with confidence about the best CpG sites or thresholds for quantitative methods. MSP has been studied mainly for CpG sites 76 to 80 and 84 to 87 and PSQ at CpG sites ranging from 72 to 95. A threshold of 9% for CpG sites 74 to 78 performed better than higher thresholds of 28% or 29% in two of three good-quality studies making such comparisons.

The Frontal Aslant Tract and Supplementary Motor Area Syndrome: Moving towards a Connectomic Initiation Axis

Simple Summary

Connectomics enables us to map whole brain networks that can be applied to operative neurosurgery to improve neuro-oncological outcomes. Damage to the superior frontal gyrus during frontal lobe surgery is thought to induce supplementary motor area (SMA) syndrome in patients. However, network-based modeling may provide a more accurate cortical model of SMA syndrome, including the Frontal Aslant Tract (FAT). The aim of our study was to retrospectively assess if surgical tractography with diffusion tensor imaging (DTI) decreases the likelihood of SMA syndrome. Compared to patients who underwent surgery preserving the SFG (n = 23), patients who had their FAT and SMA networks mapped through DTI and subsequently preserved were less likely to experience transient SMA syndrome. Preserving the FAT and SMA improves functional outcomes in patients following medial frontal glioma surgery and demonstrates how network-based approaches can improve surgical outcomes.

Abstract

Connectomics is the use of big data to map the brain’s neural infrastructure; employing such technology to improve surgical planning may improve neuro-oncological outcomes. Supplementary motor area (SMA) syndrome is a well-known complication of medial frontal lobe surgery. The ‘localizationist’ view posits that damage to the posteromedial bank of the superior frontal gyrus (SFG) is the basis of SMA syndrome. However, surgical experience within the frontal lobe suggests that this is not entirely true. In a study on n = 45 patients undergoing frontal lobe glioma surgery, we sought to determine if a ‘connectomic’ or network-based approach can decrease the likelihood of SMA syndrome. The control group (n = 23) underwent surgery avoiding the posterior bank of the SFG while the treatment group (n = 22) underwent mapping of the SMA network and Frontal Aslant Tract (FAT) using network analysis and DTI tractography. Patient outcomes were assessed post operatively and in subsequent follow-ups. Fewer patients (8.3%) in the treatment group experienced transient SMA syndrome compared to the control group (47%) (p = 0.003). There was no statistically significant difference found between the occurrence of permanent SMA syndrome between control and treatment groups. We demonstrate how utilizing tractography and a network-based approach decreases the likelihood of transient SMA syndrome during medial frontal glioma surgery. We found that not transecting the FAT and the SMA system improved outcomes which may be important for functional outcomes and patient quality of life.

The Impact of Surgery on the Survival of Patients with Recurrent Glioblastoma

Objective:

The purpose of this study was to investigate the possible benefit of repeat surgery on overall survival for patients with recurrent glioblastoma multiforme (GBM).

Methods:

We performed a retrospective analysis of data from patients who presented with recurrent GBM over a 5-year period (n = 157), comparing baseline characteristics and survival for patients who had at least 1 new tumor resection followed by chemotherapy (reoperation group, n = 59) and those who received medical treatment only (no-reoperation group, n = 98) for recurrence.

Results:

The baseline characteristics of the two groups differed in terms of WHO performance status (better in the reoperation group), mean age (60 years in the reoperation group vs. 65 years in the no-reoperation group), mean interval to recurrence (3 months later in the reoperation group than in the no-reoperation group) and more gross total resections in the reoperation group. Nevertheless, the patients in the reoperation group had a higher rate [32.8%] of sensorimotor deficits than those of the no-reoperation group [14.2]. There was no significant difference in sex; tumor localization, side, or extent; MGMT status; MIB-1 labeling index; or Karnofsky Performance Status [KPS] score. After adjustment for age, the WHO performance status, interval of recurrence, and extent of resection at the first operation, multivariate analysis showed that median survival was significantly better in the reoperation group than in the no-reoperation group (22.9 vs. 14.61 months, P < 0.05). After a total of 69 repeat operations in 59 patients (10 had 2 repeat surgeries), we noted 13 temporary and 20 permanent adverse postoperative events, yielding a permanent complication rate of 28.99% (20/69). There was also a statistically significant (P = 0.029, Student's t-test) decrease in the mean KPS score after reoperation (mean preoperative KPS score of 89.34 vs. mean postoperative score of 84.91).

Conclusion:

Our retrospective study suggests that repeat surgery may be beneficial for patients with GBM recurrence who have good functional status (WHO performance status 0 and 1), although the potential benefits must be weighed against the risk of permanent complications, which occurred in almost 30% of the patients who underwent repeat resection in this series.

Heterogeneity of radiation response in mesenchymal subtype glioblastoma: molecular profiling and reactive oxygen species generation

BACKGROUND

Radiotherapy-induced tumor death remains critical in the successful first-line management of glioblastoma, whereas resistance to radiation serves as a major factor in disease progression. Mesenchymal shift has been identified as a driver in GBM recurrence, with gene expression associated with enhanced repair of macromolecular damage caused by radiation.

METHODS

Using distinct mesenchymal subtype GBM cells lines, radiation response was assessed by clonogenic assay and orthotopic mouse tumor model. RNA-sequencing was performed in the setting of increasing radiation dosing while real-time assessment of ROS generation was achieved by the measurement of hydroxyl spin trap adducts via electron paramagnetic resonance.

RESULTS

Radiation-induced cell death determined by clonogenic assay was significantly different at low dose (4-8 Gy) between the resistant U3035 cells and the sensitive U3020 cells. Similar trends were present in the in vivo NSG mouse model following radiation dosing on post-implantation day 7-10, with the rate of reduction in tumor bioluminescence reversing between the U3020 and U3035 cells after the third dose of radiation. Changes in gene expression following radiation determined by RNA-sequencing indicate both U3035 and U3020 cells demonstrate a shift toward more mesenchymal profiles, with concurrent shift away from pro-neural subtype gene expression in the U3020 cells that appeared to develop resistance to radiation in vivo. Persistence of ROS generated following radiation was greater in U3020 cells shown to be more sensitive to radiation.

CONCLUSIONS

Despite the same molecular classification, distinct GBM cell lines can demonstrate differential response to radiation and potential for mesenchymal shift associated with radiation resistance.

Clinical features associated with the efficacy of chemotherapy in patients with glioblastoma (GBM): a surveillance, epidemiology, and end results (SEER) analysis

Background

Glioblastoma (GBM) is a highly malignant brain tumor with poor survival and prognosis. Randomized trials have demonstrated that chemotherapy improves survival in patients with GBM. This study aims to examine the clinical characteristics that are potentially associated with the efficacy of chemotherapy and the risk factors of GBM.

Methods

A total of 25,698 patients diagnosed with GBM were identified between 2004 and 2015 from the Surveillance, Epidemiology, and End Results (SEER). The clinical and demographic variables between groups were examined by Student’s t-test and Pearson’s chi-square test. GBM-specific survival (GBMSS) and overall survival (OS) were evaluated using the Kaplan-Meier method with the log-rank test. Univariable and multivariable analyses were also performed using the Cox proportional hazards model to identify statistically significant prognostic factors.

Results

Patients who received chemotherapy had better overall survival (median OS 13 vs. Three months, HR = 1.9224, 95%CI 1.8571–1.9900, p < 0.0001) and better GBMSS (median GBMSS of 12 vs. Three months, HR = 1.9379, 95%CI 1.8632–2.0156, p < 0.0001), compared to patients who did not. Further subgroup analysis revealed that among patients who underwent chemotherapy, those who were younger, with a supratentorial tumor, received surgery, or radiotherapy had both improved OS and GBMSS. Age, race, tumor location, tumor size, and treatments were identified as independent prognostic factors by multivariable analyses for patients with glioblastoma.

Conclusion

Patients with GBM who were younger (< 65 years), underwent surgery, or radiotherapy can benefit more from chemotherapeutic regimens. Age, race, tumor size, tumor location, surgery, radiotherapy, and chemotherapy were factors associated with the prognosis of patients with GBM.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-07800-0.

Radiotherapy for glioblastoma in the elderly: A protocol for systematic review and meta-analysis

BACKGROUND

Glioblastoma is an aggressive form of brain cancer with significant morbidity and mortality. This study aims to determine the radiotherapy for treatment of elderly people with diagnosed glioblastoma.

METHOD

This study adheres to the Preferred Reporting Items for Systematic Reviews and Meta-analysis for Protocols. Chinese electronic Database (CBM, Wanfang, and CNKI) and international electronic databases (PubMed, Embase, Cochrane Library, and Web of Science) will be searched for all relevant published articles, with no restrictions on the year of publication or language. Study selection, data collection, and assessment of study bias will be conducted independently by a pair of independent reviewers. The Cochrane Risk of bias (ROB) tool will be used for the risk of bias assessment. The Grading of Recommendations Assessment Development and Evaluation (GRADE) system will be used to assess the quality of evidence. The statistical analysis of this meta-analysis will be calculated by Review manager version 5.3.

RESULTS

The results of this study will be published in a peer-reviewed journal.

CONCLUSION

The findings of this review will to provide high-level evidence in terms of the benefits and harms of radiotherapy in people with glioblastoma to provide meaningful conclusions for clinical practice and further research.

TRIAL REGISTRATION

This study protocol was registered in open Science framework (OSF), (Registration DOI: 10.17605/OSF.IO/A6BCS).

Postoperative Prolonged Mechanical Ventilation in Patients With Newly Diagnosed Glioblastoma-An Unrecognized Prognostic Factor

Objective

Although the treatment of glioblastoma patients is well established in neuro-oncological surgery, precious scarce data is available on patients with glioblastoma requiring postoperative prolonged mechanical ventilation (PMV). Therefore, the aim of the present study was to determine the influence of PMV on overall survival (OS) in patients with glioblastoma.

Methods

Patients with newly diagnosed glioblastoma who had undergone surgical therapy and complete subsequent neuro-oncological treatment at the authors’ neuro-oncological center from January 2013 to December 2018 were selected and included in the further analysis. PMV was defined as mechanical ventilation for more than 24 h after surgery. Survival analyses were performed, including established prognostic factors such as age, Karnofsky performance score, MGMT-promoter methylation status and extent of resection.

Results

A total of 240 patients with newly diagnosed glioblastoma and subsequent surgical treatment were identified. 13 patients (5%) suffered from PMV during the treatment course of glioblastoma. All but one patient were successfully weaned from mechanical ventilation. Patients suffering from PMV achieved significantly less often favorable functional outcome after 3, 6, 9, and 12 months compared to patients without PMV. Multivariate analysis revealed PMV to constitute a significant prognostic factor for OS, independent of other prognostic factors (p<0.0001, OR 6.7, 95% CI 3.2–13.8).

Conclusions

The present study identifies PMV as significantly associated with impaired functional outcome and poor OS in patients suffering from newly diagnosed glioblastoma. These findings encourage further efforts to investigate/assess this prognostic factor in future studies.

Research progress on radiotherapy technology and dose fraction scheme for advanced gliomas

Glioma is the most common central malignant tumor. High-grade glioma (HGG) has high malignancy and a short median survival. Complete surgical resection and comprehensive treatment with postoperative radiotherapy and chemotherapy is the recommended treatment for HGGs at present in clinic. Postoperative radiotherapy can reduce the local recurrence rate and prolong the survival time of patients. In recent years, researchers have made some progress on different radiotherapy technologies and dose fraction schemes. With the continuous development of medical technology, different groups of people should choose different dose fraction schemes, in order to realize the individualization of treatment schemes, and provide more benefits to patients. At present, the optimal radiotherapy dose, the fraction model, and how to achieve individualized radiotherapy remains unclear. In view of the poor prognosis of this disease, patients should be encouraged to participate in properly conducted experimental studies.

The role of radiation therapy in treatment of adults with newly diagnosed glioblastoma multiforme: a systematic review and evidence-based clinical practice guideline update

TARGET POPULATION

These recommendations apply to adult patients diagnosed with newly diagnosed glioblastoma. QUESTION 1 : In adult patients (aged 65 and under) with newly diagnosed glioblastoma, is the addition of radiation therapy (RT) more beneficial than management without RT in improving survival?

RECOMMENDATIONS

Level I: Radiation therapy (RT) is recommended for the treatment of newly diagnosed malignant glioblastoma in adults. QUESTION 2 : In adult patients (aged 65 and under) with newly diagnosed glioblastoma, is the RT regimen of 60 Gy given in 2 Gy daily fractions more beneficial than alternative regimens in providing survival benefit while minimizing toxicity?

RECOMMENDATIONS

Level I: Treatment schemes should include dosage of up to 60 Gy given in 2 Gy daily fractions that includes the enhancing area. QUESTION 3 : In adult patients (aged 65 and under) with newly diagnosed glioblastoma, is a tailored target volume superior to regional RT for reduction of radiation-induced toxicity while maintaining efficacy?

RECOMMENDATION

Level II: It is recommended that radiation therapy planning include 1-2 cm margin around the radiographically T1 weighted contrast-enhancing tumor volume or the T2 weighted abnormality on MRI. Level III: Recalculation of the radiation volume during RT treatment may be necessary to reduce the radiated volume of normal brain since the volume of surgical defect will change during the long period of RT. QUESTION 4 : In adult patients (aged 65 and under) with newly diagnosed glioblastoma, does the addition of RT of the subventricular zone to standard tumor volume treatment improve tumor control and overall survival?

RECOMMENDATION

No recommendation can be formulated as there is contradictory evidence in favor of and against intentional radiation of the subventricular zone (SVZ) QUESTION 5 : In elderly (age > 65 years) and/or frail patients with newly diagnosed glioblastoma, does the addition of RT to surgical intervention improve disease control and overall survival?

RECOMMENDATION

Level I: Radiation therapy is recommended for treatment of elderly and frail patients with newly diagnosed glioblastoma to improve overall survival. QUESTION 6 : In elderly (age > 65 years) and/or frail patients with newly diagnosed glioblastoma, does modification of RT dose and fractionation scheme from standard regimens decrease toxicity and improve disease control and survival?

RECOMMENDATION

Level II: Short RT treatment schemes are recommended in frail and elderly patients as compared to conventional 60 Gy given in 2 daily fractions because overall survival is not different while RT risk profile is better for the short RT scheme. Level II: The 40.05 Gy dose given in 15 fractions or 25 Gy dose given in 5 fractions or 34 Gy dose given in 10 fractions should be considered as appropriate doses for Short RT treatments in elderly and/or frail patients. QUESTION 7 : In adult patients with newly diagnosed glioblastoma is there advantage to delaying the initiation of RT instead of starting it 2 weeks after surgical intervention in decreasing radiation-induced toxicity and improving disease control and survival?

RECOMMENDATION

Level III: It is suggested that RT for patients with newly diagnosed GBM starts within 6 weeks of surgical intervention as compared to later times. There is insufficient evidence to recommend the optimal specific post-operative day within the 6 weeks interval to start RT for adult patients with newly diagnosed glioblastoma that have undergone surgical resection. QUESTION 8 : In adult patients with newly diagnosed supratentorial glioblastoma is Image-Modulated RT (IMRT) or similar techniques as effective as standard regional RT in providing tumor control and improve survival?

RECOMMENDATION

Level III: There is no evidence that IMRT is a better RT delivering modality when compared to conventional RT in improving overall survival in adult patients with newly diagnosed glioblastoma. Hence, IMRT should not be preferred over the Conventional RT delivery modality. QUESTION 9 : In adult patients with newly diagnosed glioblastoma does the use of radiosensitizers with RT improve the efficacy of RT as determined by disease control and overall survival?

RECOMMENDATION

Level III: Iododeoxyuridine is not recommended to be used as radiosensitizer during RT treatment for patients with newly diagnosed GBM QUESTION 10 : In adult patients with newly diagnosed glioblastoma is the use of Ultrafractionated RT superior to standard fractionation regimens in improving disease control and survival?

RECOMMENDATION

There is insufficient evidence to formulate a recommendation regarding the use of ultrafractionated RT schemes and patient population that could benefit from it. QUESTION 11 : In patients with poor prognosis with newly diagnosed glioblastoma is hypofractionated RT indicated instead of a standard fractionation regimen as measured by extent of toxicity, disease control and survival?

RECOMMENDATION

Level I: Hypofractionated RT schemes may be used for patients with poor prognosis and limited survival without compromising response. There is insufficient evidence in the literature for us to be able to recommend the optimal hypofractionated RT scheme that will confer longest overall survival and/or confer the same overall survival with less toxicities and shorter treatment time. QUESTION 12 : In adult patients with newly diagnosed glioblastoma is the addition of brachytherapy to standard fractionated RT indicated to improve disease control and survival?

RECOMMENDATION

Level I: Brachytherapy as a boost to external beam RT has not been shown to be beneficial and is not recommended in the routine management of patients with newly diagnosed GBM. QUESTION 13 : In elderly patients (> 65 year old) with newly diagnosed glioblastoma under what circumstances is accelerated hyperfractionated RT indicated instead of a standard fractionation regimen as measured by extent of toxicity, disease control and survival?

RECOMMENDATION

Level III: Accelerated Hyperfractionated RT with a total RT dose of 45 Gy or 48 Gy has been shown to shorten the treatment time without detriment in survival when compared to conventional external beam RT and should be considered as an option for treatment of elderly patients with newly diagnosed GBM. QUESTION 14 : In adult patients with newly diagnosed glioblastoma is the addition of Stereotactic Radiosurgery (SRS) boost to conventional standard fractionated RT indicated to improve disease control and survival?

RECOMMENDATION

Level I: Stereotactic Radiosurgery boost to external beam RT has not been shown to be beneficial and is not recommended in patients undergoing routine management of newly diagnosed malignant glioma.

Congress of neurological surgeons systematic review and evidence-based guidelines update on the role of chemotherapeutic management and antiangiogenic treatment of newly diagnosed glioblastoma in adults

QUESTION

What is the role of temozolomide in the management of adult patients (aged 65 and under) with newly diagnosed glioblastoma?

TARGET POPULATION

These recommendations apply to adult patients diagnosed with newly diagnosed glioblastoma.

RECOMMENDATION

Level I: Concurrent and post-irradiation Temozolomide (TMZ) in combination with radiotherapy and post-radiotherapy as described by Stupp et al. is recommended to improve both PFS and OS in adult patients with newly diagnosed GBM. There is no evidence that alterations in the dosing regimen have additional beneficial effect.

QUESTION

Is there benefit to adjuvant temozolomide treatment in elderly patients (> 65 years old?).

TARGET POPULATION

These recommendations apply to adult patients diagnosed with newly diagnosed glioblastoma.

RECOMMENDATION

Level III: Adjuvant TMZ treatment is suggested as a treatment option to improve PFS and OS in adult patients (over 70 years of age) with newly diagnosed GBM.

QUESTION

What is the role of local regional chemotherapy with BCNU biodegradable polymeric wafers in adult patients with newly diagnosed glioblastoma?

TARGET POPULATION

These recommendations apply to adult patients diagnosed with newly diagnosed glioblastoma.

RECOMMENDATION

Level III: There is insufficient evidence for the use of BCNU wafers following resection in patients with newly diagnosed glioblastoma who undergo the Stupp protocol after surgery. Further studies of higher quality are suggested to understand the role of BCNU wafer and other locoregional therapy in the setting of Stupp Protocol.

QUESTION

What is the role of bevacizumab in the adult patient with newly diagnosed glioblastoma?

TARGET POPULATION

These recommendations apply to adult patients diagnosed with newly diagnosed glioblastoma.

RECOMMENDATION

Level I: Bevacizumab in general is not recommended in the initial treatment of adult patients with newly diagnosed GBM. It continues to be strongly recommended that patients with newly diagnosed GBM be enrolled in properly designed clinical trials to assess the benefit of novel chemotherapeutic agents compared to standard therapy.

Time to treatment initiation and outcomes in high-grade glioma patients in rehabilitation: a retrospective cohort study

Aims: To investigate wait time (WT) for chemoradiation and survival in post-op high-grade glioma (HGG) patients admitted to inpatient rehabilitation compared with those discharged home. Materials & methods: A total of 291 HGG patients (14.4% grade III and 84.9% grade IV) were included in this retrospective cohort study. Patients were grouped by disposition following surgery. Results: Median length of stay was longer in acute inpatient rehabilitation facility (AIRF) patients (10d) compared with patients discharged home (3d). AIRF admission was associated with higher odds of excessive treatment delay. Median survival for AIRF patients less than for patients discharged home (42.9 vs 72.71 weeks). WT was not associated with survival even after adjusting for prognostic factors. Conclusion: HGG patients discharged to rehabilitation facilities have longer length of stay, longer WT and shorter survival compared with patients discharged home.

Carmustine as a Supplementary Therapeutic Option for Glioblastoma: A Systematic Review and Meta-Analysis

Background: Glioblastoma (GBM) is the most aggressive type of primary malignant brain tumor. Carmustine is used by intravenous injection or local implantation in the resection cavity for gliomas, including GBMs. However, the therapeutic potential of carmustine is not well-recognized. This analysis aimed to evaluate the survival benefits of carmustine in glioma patients, especially those with GBM. Methods: Randomized controlled trials (RCTs) and cohort studies regarding carmustine for glioma treatment were searched in PubMed, the Cochrane Library, and Embase from January 1979 to March 2020. Quality assessment was conducted with Jadad and Newcastle-Ottawa scales (NOS). Statistical analysis was conducted by the Revman 5.3 software. Results: Twenty-two eligible RCTs and cohort studies involving 5,821 glioma patients were included. Overall, glioma patients receiving carmustine as an adjuvant therapy had better progression-free survival [PFS; hazard ratio (HR) = 0.85, 95% CI = 0.77-0.94, P = 0.002] and overall survival (OS; HR = 0.85, 95% CI = 0.79-0.92, P < 0.0001) than those without carmustine treatment. Subgroup analysis showed that the OS benefit was observed in GBM (HR = 0.84, 95% CI = 0.78-0.91, P < 0.00001) but not in anaplastic glioma patients (HR = 1.20, 95% CI = 0.70-2.07, P = 0.50). Additionally, both newly diagnosed and recurrent GBM patients who received carmustine treatment showed better OS (HR = 0.86, 95% CI = 0.79-0.95, P = 0.002; HR = 0.77, 95% CI = 0.67-0.89, P = 0.0002, respectively). Both carmustine implantation in resection cavity and intravenous administration significantly prolonged OS (HR = 0.84, 95% CI = 0.78-0.92, P < 0.0001; HR = 0.86, 95% CI = 0.75-0.99, P = 0.04, respectively). Moreover, GBM patients receiving a combined carmustine and temozolomide (TMZ) therapy had longer OS than those receiving TMZ alone (HR = 0.78, 95% CI = 0.63-0.97, P = 0.03). Conclusion: Carmustine implantation in resection cavity provides survival benefit for GBM patients, and it may be a promising supplement to standard therapeutic protocol by offering a bridge between surgical resection and onset of TMZ therapy.

Ethyl pyruvate inhibits glioblastoma cells migration and invasion through modulation of NF-κB and ERK-mediated EMT

Background

Glioblastoma is a grade IV glioma with the highest degree of malignancy and extremely high incidence. Because of the poor therapeutic effect of surgery and radiochemotherapy, glioblastoma has a high recurrence rate and lethality, and is one of the most challenging tumors in the field of oncology. Ethyl pyruvate (EP), a stable lipophilic pyruvic acid derivative, has anti-inflammatory, antioxidant, immunomodulatory and other cellular protective effects. It has been reported that EP has potent anti-tumor effects on many types of tumors, including pancreatic cancer, prostate cancer, liver cancer, gastric cancer. However, whether EP has anti-tumor effect on glioblastoma or not is still unclear.

Methods

Glioblastoma U87 and U251 cells were treated with different concentrations of EP for 24 h or 48 h. CCK8 assay and Colony-Formation assay were performed to test the viability and proliferation. Wound-healing assay and Transwell assay were carried out to measure cell invasion and migration. Western blot was not only used to detect the protein expression of epithelial-mesenchymal transition (EMT)-related molecules, but also to detect the expression and activation levels of NF-κB (p65) and Extracellular Signal Regulated Kinase (ERK).

Results

In glioblastoma U87 and U251 cells treated with EP, the viability, proliferation, migration, invasion abilities were inhibited in a dose-dependent manner. EP inhibited EMT and the activation of NF-κB (p65) and ERK. With NF-κB (p65) and ERK activated, EMT, migration and invasion of U87 and U251 cells were promoted. However the activation of NF-κB (p65) and ERK were decreased, EMT, migration and invasion abilities were inhibited in U87 and U251 cells treated with EP.

Conclusion

EP inhibits glioblastoma cells migration and invasion by blocking NF-κB and ERK-mediated EMT.

Early imaging marker of progressing glioblastoma: a window of opportunity

PURPOSE

Therapeutic intervention at glioblastoma (GBM) progression, as defined by current assessment criteria, is arguably too late as second-line therapies fail to extend survival. Still, most GBM trials target recurrent disease. We propose integration of a novel imaging biomarker to more confidently and promptly define progression and propose a critical timepoint for earlier intervention to extend therapeutic exposure.

METHODS

A retrospective review of 609 GBM patients between 2006 and 2019 yielded 135 meeting resection, clinical, and imaging inclusion criteria. We qualitatively and quantitatively analyzed 2000+ sequential brain MRIs (initial diagnosis to first progression) for development of T2 FLAIR signal intensity (SI) within the resection cavity (RC) compared to the ventricles (V) for quantitative inter-image normalization. PFS and OS were evaluated using Kaplan-Meier curves stratified by SI. Specificity and sensitivity were determined using a 2 × 2 table and pathology confirmation at progression. Multivariate analysis evaluated SI effect on the hazard rate for death after adjusting for established prognostic covariates. Recursive partitioning determined successive quantifiers and cutoffs associated with outcomes. Neurological deficits correlated with SI.

RESULTS

Seventy-five percent of patients developed SI on average 3.4 months before RANO-assessed progression with 84% sensitivity. SI-positivity portended neurological decline and significantly poorer outcomes for PFS (median, 10 vs. 15 months) and OS (median, 20 vs. 29 months) compared to SI-negative. RC/V ratio ≥ 4 was the most significant prognostic indicator of death.

CONCLUSION

Implications of these data are far-reaching, potentially shifting paradigms for glioma treatment response assessment, altering timepoints for salvage therapeutic intervention, and reshaping glioma clinical trial design.

Optimal timing of chemoradiotherapy after surgical resection of glioblastoma: Stratification by validated prognostic classification

BACKGROUND

Previous studies examining the time to initiate chemoradiation (CRT) after surgical resection of glioblastoma have been conflicting. To better define the effect that the timing of adjuvant treatment may have on outcomes, the authors examined patients within the National Cancer Database (NCDB) stratified by a validated prognostic classification system.

METHODS

Patients with glioblastoma in the NCDB who underwent surgery and CRT from 2004 through 2013 were analyzed. Radiation Therapy Oncology Group recursive partitioning analysis (RPA) class (III, IV, V) was extrapolated for the cohort. Time intervals were grouped weekly, with weeks 4 to 5 serving as the reference category for analyses. Kaplan-Meier analysis, log-rank testing, and multivariate (MVA) Cox proportional hazards regression were performed.

RESULTS

In total, 30,414 patients were included. RPA classes III, IV, and V contained 5250, 20,855, and 4309 patients, respectively. On MVA, no time point after week 5 was associated with a change in overall survival for the entire cohort or for any RPA class subgroup. The periods of weeks 0 to 1 (hazard ratio [HR], 1.18; 95% CI, 1.02-1.36), >1 to 2 (HR, 1.23; 95% CI, 1.16-1.31), and >2 to 3 (HR, 1.11; 95% CI, 1.07-1.15) demonstrated slightly worse overall survival (all P < .03). The detriment to early initiation was consistent across each RPA class subgroup.

CONCLUSIONS

The current data provide insight into the optimal timing of CRT in patients with glioblastoma and describe RPA class-specific outcomes. In general, short delays beyond 5 weeks did not negatively affect outcomes, whereas early initiation before 3 weeks may be detrimental.

Optimal Timing of Radiotherapy Following Gross Total or Subtotal Resection of Glioblastoma: A Real-World Assessment using the National Cancer Database

Treatment for glioblastoma (GBM) includes surgical resection and adjuvant radiotherapy (RT) and chemotherapy. The optimal time interval between surgery and RT remains unclear. The National Cancer Database (NCDB) was queried for patients with GBM. Overall survival (OS) was estimated using Kaplan-Meier and log-rank tests. Univariate (UVA) and multivariable Cox regression (MVA) modeling was used to determine predictors of OS. A total of 45,942 patients were included. On MVA: younger age, female gender, black ethnicity, higher KPS, obtaining a gross total resection (GTR), MGMT promoter-methylated gene status, unifocal disease, higher RT dose, and RT delay of 4–8 weeks had improved OS. Patients who underwent a subtotal resection (STR) had worsened survival with RT delay ≤4 weeks and patients with GTR had worsened survival when RT was delayed >8 weeks. This analysis suggests that an interval of 4–8 weeks between resection and RT results in better survival. Delays >8 weeks in patients with a GTR and delays <4 weeks in patients with a STR/biopsy resulted in worse survival. This impact of time delay from surgery to RT, in conjunction with extent of resection, should be considered in the clinical management of patients and future designs of clinical trials.

Implantation of carmustine wafers (Gliadel®) for high-grade glioma treatment. A 9-year nationwide retrospective study

BACKGROUND

Carmustine wafers (CW) are approved to treat newly or recurrent high-grade gliomas (HGG). Widespread use has been limited regarding some doubtful uncertainties about their efficacy, related increased risk of infection and expensive cost.

OBJECTIVE

To describe the epidemiology of CW implantation, search for related complications, long-term survival and associated prognostic factors.

METHODS

We processed the French medico-administrative national database to retrieve appropriate cases operated between 2010 and 2018. A survival analysis was conducted.

RESULTS

We identified 1659 patients treated in 39 institutions. Median age at CW implantation was 61 years and there was an over-representation of male (63.5%). 491 patients (29.6%) had previous diagnosis of glioma. Time between the first surgery and CW implantation was 0.9 years, IQR[0.6, 1.6]. The frontal lobe was the most frequently involved 29%. 131 patients (7.9%) had to be re operated on for a complication of which 121 for surgical site infection. At one year, 514 patients (31%) had died. Median overall survival (OS) was 1.4 years, _95% CI [1.3, 1.5]. OS at 1 and 2 year was 66%, _95%CI [63.7, 68.5], 32.3%, _95%CI [29.9, 35]. In the adjusted Cox regression, male gender & age at CW implantation were established as independent factors of OS in all three groups. Patients with recurrent HGG have a significant worse prognosis (HR = 0.71, _95% CI [0.62, 0.80] p < 0.001). A post-operative diagnosis of infection or intracranial bleeding eventually leading to a redo surgery was not associated with a decrease OS.

CONCLUSION

Over the past 9 years, there is a significant decrease utilisation of CW in France. OS after CW implantation is significantly variable as influenced by many factors such as age, gender or recurrent disease but not by post-operative complications. Compare to previous results, CW may increase the OS and this effect seems more pronounced when adjuvant RT/TMZ is given.

The American Brachytherapy Society consensus statement on intraoperative radiation therapy

PURPOSE

Although radiation therapy has traditionally been delivered with external beam or brachytherapy, intraoperative radiation therapy (IORT) represents an alternative that may shorten the course of therapy, reduce toxicities, and improve patient satisfaction while potentially lowering the cost of care. At this time, there are limited evidence-based guidelines to assist clinicians with patient selection for IORT. As such, the American Brachytherapy Society presents a consensus statement on the use of IORT.

METHODS

Physicians and physicists with expertise in intraoperative radiation created a site-directed guideline for appropriate patient selection and utilization of IORT.

RESULTS

Several IORT techniques exist including radionuclide-based high-dose-rate, low-dose-rate, electron, and low-energy electronic. In breast cancer, IORT as monotherapy should only be used on prospective studies. IORT can be considered in the treatment of sarcomas with close/positive margins or recurrent sarcomas. IORT can be considered in conjunction with external beam radiotherapy for retroperitoneal sarcomas. IORT can be considered for colorectal malignancies with concern for positive margins and in the setting of recurrent gynecologic cancers. For thoracic, head and neck, and central nervous system malignancies, utilization of IORT should be evaluated on a case-by-case basis.

CONCLUSIONS

The present guidelines provide clinicians with a summary of current data regarding IORT by treatment site and guidelines for the appropriate patient selection and safe utilization of the technique. High-dose-rate, low-dose-rate brachytherapy methods are appropriate when IORT is to be delivered as are electron and low-energy based on the clinical scenario.

Short delay in initiation of radiotherapy for patients with glioblastoma-effect of concurrent chemotherapy: a secondary analysis from the NRG Oncology/Radiation Therapy Oncology Group database

Background

We previously reported the unexpected finding of significantly improved survival for newly diagnosed glioblastoma in patients when radiation therapy (RT) was initiated later (>4 wk post-op) compared with earlier (≤2 wk post-op). In that analysis, data were analyzed from 2855 patients from 16 NRG Oncology/Radiotherapy Oncology Group (RTOG) trials conducted prior to the era of concurrent temozolomide (TMZ) with RT. We now report on 1395 newly diagnosed glioblastomas from 2 studies, treated with RT and concurrent TMZ followed by adjuvant TMZ. Our hypothesis was that concurrent TMZ has a synergistic/radiosensitizing mechanism, making RT timing less significant.

Methods

Data from patients treated with TMZ-based chemoradiation from NRG Oncology/RTOG 0525 and 0825 were analyzed. An analysis comparable to our prior study was performed to determine whether there was still an impact on survival by delaying RT. Overall survival (OS) was investigated using the Kaplan-Meier method and Cox proportional hazards model. Early progression (during time of diagnosis to 30 days after RT completion) was analyzed using the chi-square test.

Results

Given the small number of patients who started RT early following surgery, comparisons were made between >4 and ≤4 weeks delay of radiation from time of operation. There was no statistically significant difference in OS (hazard ratio = 0.93; P = 0.29; 95% CI: 0.80-1.07) after adjusting for known prognostic factors (recursive partitioning analysis and O6-methylguanine-DNA methyltransferase methylation status). Similarly, the rate of early progression did not differ significantly (P = 0.63).

Conclusions

We did not observe a significant prognostic influence of delaying radiation when given concurrently with TMZ for newly diagnosed glioblastoma. The effects of early (1-3 wk post-op) or late (>5 wk) initiation of radiation tested in our prior study could not be replicated.

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

OBJECTIVE

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.

METHODS

We retrospectively reviewed the clinical data of 375 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.

RESULTS

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. 9.0 months, P = 0.0384 and OS 23.0 vs. 17.0 months, 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).

CONCLUSIONS

This retrospective study highlights that super-early initiation of TMZ in newly diagnosed GBM may confer to survival benefit, especially for those without GTR.

Impact of time to initiation of radiotherapy on survival after resection of newly diagnosed glioblastoma

Background and purpose

To evaluate the effect of timing of radiotherapy (RT) on survival in patients with newly diagnosed primary glioblastoma (GBM) treated with the same therapeutical protocol.

Materials and methods

Patients with newly diagnosed primary GBM treated with the same therapeutical scheme between 2010 and 2015 in our institution were retrospectively reviewed. The population was trichotomized based on the time interval from surgery till initiation of RT (< 28 days, 28–33 days, > 33 days). Kaplan-Meier and Cox regression analyses were used to compare progression free survival (PFS) and overall survival (OS) between the groups. The influence of various extensively studied prognostic factors on survival was assessed by multivariate analysis.

Results

One-hundred-fifty-one patients met the inclusion criteria. Between the three groups no significant difference in PFS (p = 0.516) or OS (p = 0.902) could be demonstrated. Residual tumor volume (RTV) and midline structures involvement were identified as independent prognostic factors of PFS while age, O-6-Methylguanine Methyltransferase (MGMT) status, Ki67 index, RTV and midline structures involvement represented independent predictors of OS. Patients starting RT after a prolonged delay (> 48 days) exhibited a significantly shorter OS (p = 0.034).

Conclusion

Initiation of RT within a timeframe of 48 days is not associated with worsened survival. A prolonged delay (> 48 days) may be associated with worse OS. RT should neither be delayed, nor forced, but should rather start timely, as soon as the patient has recovered from surgery.

The Impact of Timing of Concurrent Chemoradiation in Patients With High-Grade Glioma in the Era of the Stupp Protocol

Background: The purpose of this study is to provide a critical review of current evidence for the impact of time to initiation of chemoradiation on overall survival in patients with newly diagnosed high-grade gliomas treated with radiation and concurrent temozolomide chemotherapy.

Methods: A literature search was conducted using PubMed/MEDLINE and EMBASE databases. Studies were included if they provided separate analysis for patients treated with current standard of care: radiation and concurrent temozolomide. Bias assessment was performed for each included study using the Newcastle-Ottawa Assessment Scale, with Karnofsky Performance Status (KPS) and extent of resection used for comparability.

Results: The initial search yielded 575 citations. Based on the inclusion/exclusion criteria, a total of 10 retrospective cohort studies were included in this review for a total of 30,298 patients. Of these, one study described an indirect relationship between time to initiation of treatment and overall survival. One study found decreased survival only with patients with significantly longer time to treatment. Four studies found no significant effect of time to treatment on overall survival. The four remaining studies found that patients with moderate time to initiation had the best overall survival.

Conclusion: This review provides evidence that moderate time to initiation of chemoradiotherapy in patients with high-grade gliomas does not lead to a significant decrease in overall survival, though the effect of significant delays in treatment initiation remains unclear.

The impact of the time to start radiation therapy on overall survival in newly diagnosed glioblastoma

PURPOSE

The standard treatment for newly diagnosed glioblastoma includes maximal safe surgical resection followed by concurrent radiation therapy and temozolomide (TMZ) and maintenance TMZ. The impact of time to start radiation therapy (TRT) on overall survival (OS) in glioblastoma patients is controversial. The study aimed to evaluate the impact of TRT on OS in patients diagnosed with glioblastoma who received standard treatment.

METHODS

In this retrospective study, we included patients with confirmed diagnosis of glioblastoma treated from 2011 to 2016. TRT was defined as the time between surgery (biopsy or resection) and the first day of radiation therapy. The endpoint was OS. The patients were divided according to the TRT in three categories: < 30 days, 30-60 days and ≥ 60 days.

RESULTS

A total of 134 patients were included with a mean age of 51.82 years (range 19-78 years). Median TRT was 80 days. On univariate and multivariable analysis, we identified age as the only significant independent predictor for OS. There was no statistically significant negative impact of TRT on OS (p = 0.47).

CONCLUSIONS

There was no clear evidence that delaying post-operative combined chemoradiotherapy negatively impacts OS, not even for TRT longer than 60 days.

Survival Impact of Delaying Postoperative Radiotherapy in Patients with Esophageal Cancer

The purpose of the current study was to retrospectively assess the effect of postoperative radiotherapy (RT) delay on survival for patients with esophageal cancer. From 2008 to 2011, patients with esophageal cancer who had undergone postoperative RT in five different hospitals in China were reviewed. Clinical data, including time interval between surgery to RT, were prospectively collected. Kaplan-Meier method was conducted to estimate the effect of each variable on progression-free survival (PFS) and overall survival (OS), with differences assessed by log-rank test. Univariate Cox proportional-hazards models were performed for both PFS and OS for all assumed predictor variables. Statistically significant predictor variables (P < .05) on univariate analysis were then included in multivariate Cox proportional-hazards models, which were performed to compare the effects of RT delay on PFS and OS. A total of 316 patients were finally enrolled in this prospectively multicentric study. Time to RT after surgery varied from 12 days to over 60 days (median, 26 days). Multivariate analysis showed that delay to RT longer than the median does not appear to be a survival cost. There was also no statistically difference in PFS (P = .513) or OS (P = .236) between patients stratified by quartiles (≤21 days vs ≧35 days). However, patients with particularly long delays (≧42 days) demonstrated a detrimental impact on OS (P = .021) but not PFS (P = .580). Delaying postoperative RT of esophageal cancer does not impact PFS, but results in a significant reduction on OS if delaying longer than 6 weeks.

[Early postsurgical temozolomide treatment in newly diagnosed bad prognosis glioblastoma patients: Feasibility study]

INTRODUCTION

Despite the combined adjuvant treatment of radiotherapy plus chemotherapy with temozolomide (TMZ) followed by 6 cycles of temozolomide after surgery, the prognosis of patients with glioblastoma remains poor. We conducted a monocentric prospective study to explore the tolerance and potential efficacy of an early temozolomide cycle after surgery.

METHOD

Patients with newly diagnosed glioblastoma (unmutated IDH1) and of poor prognosis (age>50 years, biopsy or partial resection or unmethylated MGMT promoter) were prospectively included from June 2014 to 2017. They all received a cycle of 5 days of temozolomide between surgery and the combined adjuvant treatment.

RESULTS

Twelve patients of median age 64.5 years (45-73) were included in the study. The median doses of temozolomide administered were respectively 265mg (225-300) for the early cycle; 130mg (110-150) for the concomitant treatment and 310mg (225-400) for the adjuvant one. Side effects during treatment were grade III lymphopenia, grade III neutropenia, fatigue and nausea/vomiting respectively in 4, 1, 7 and 5 patients. Progression-free survival and overall survival were respectively 90% and 91.7% at 6 months; 58.3 and 71.3% at 12 months; 31.1 and 71.3% at 18 months.

CONCLUSION

Early postsurgical temozolomide treatment prior to standard adjuvant therapy for poor prognosis glioblastoma patients in our small prospective series presents toxicity and survival similar to those published in the literature for the general population of glioblastoma. These encouraging results should be confirmed by a multicentric study comparing this regiment with the standard treatment.

Does the interval from tumour surgery to radiotherapy influence survival in paediatric high grade glioma?

PURPOSE

Paediatric high grade glioma (pHGG) are rare. Following maximum safe resection, children >3 years with HGG receive radiotherapy as standard of care. Whether the interval from tumour surgery to radiotherapy (ISRT) influences survival is disputed in adults with glioblastoma, data for children are lacking. This retrospective single-centre analysis investigates a possible impact of ISRT on survival in paediatric patients with HGG.

METHODS

Survival was analysed in patients aged 3-19 years with non-pontine HGG.

RESULTS

Thirty-eight patients were included (female:male 19:19) with a median age of 11.0 years (3.4-17.7). Seventeen patients had grade 3 and 21 grade 4 glioma. Gross total resection was achieved in 26.3%, partial resection in 36.8% and 36.8% underwent biopsy only. All patients received concomitant and adjuvant chemotherapy. Fifty percent (n = 19) started irradiation ≤17 days (median interval 12 days [range 5-17]), 50% thereafter (median 28 days [range 19-78]). More patients with grade 4 tumours were irradiated shortly after surgery. ISRT (as a continuous variable and dichotomised into two groups by the median ISRT of 18 days) did not significantly influence overall survival (OS) or progression-free survival (PFS). Higher extent of resection (EOR), lower tumour grade as well as chemotherapy with temozolomide had a significant positive impact on OS and PFS in univariate analysis and (except for the effect of temozolomide on PFS) also in multivariable analysis.

CONCLUSIONS

ISRT did not influence survival in pHGG. In view of upcoming targeted treatment options in pHGG the present data suggest that it is safe to perform molecular analyses within a 4-week timeframe before radiotherapy.

Residual enhancing disease after surgery for glioblastoma: evaluation of practice in the United Kingdom

BACKGROUND

A growing body of clinical data highlights the prognostic importance of achieving gross total resection (GTR) in patients with glioblastoma. The aim of this study was to determine nationwide practice and attitudes towards achieving GTR and dealing with residual enhancing disease.

METHODS

The study was in 2 parts: an electronic questionnaire sent to United Kingdom neuro-oncology surgeons to assess surgical practice followed by a 3-month prospective, multicenter observational study of current neurosurgical oncology practice.

RESULTS

Twenty-seven surgeons representing 22 neurosurgical units completed the questionnaire. Prospective data were collected for 113 patients from 15 neurosurgical units. GTR was deemed to be achieved at time of surgery in 82% (91/111) of cases, but in only 45% (36/80) on postoperative MRI. Residual enhancing disease was deemed operable in 16.3% (13/80) of cases, however, no patient underwent early repeat surgery for residual enhancing disease. The most commonly cited reason (38.5%, 5/13) was perceived lack of clinical benefit.

CONCLUSION

There is a subset of patients for whom GTR is thought possible, but not achieved at surgery. For these patients, early repeat resection may improve overall survival. Further prospective surgical research is required to better define the prognostic implications of GTR for residual enhancing disease and examine the potential benefit of this early re-intervention.

Impact of Timing of Adjuvant Chemoradiation for Glioblastoma in a Large Hospital Database

BACKGROUND

Although the standard of care for glioblastoma remains maximal safe resection followed by chemoradiation, conflicting reports have emerged regarding the importance of the time interval between these 2 treatments.

OBJECTIVE

To assess whether differences in the duration between surgery and initiation of chemoradiation for glioblastoma had an impact on overall survival (OS) in a large hospital-based database.

METHODS

The National Cancer Database was queried to identify patients diagnosed with glioblastoma between 2010 and 2012 treated with surgery followed by chemoradiation. Patients who received biopsy only were excluded. The time from surgery to initiation of radiation therapy was divided into 4 equal quartiles of ≤24, 25 to 30, 31 to 37, and &gt;37 d. Patient characteristics were compared between groups using Pearson Chi Square and Fisher's Exact test. OS was analyzed via the Kaplan–Meier method and compared via the log-rank test. Univariable and multivariable Cox regression were performed to assess for impact of covariables on OS.

RESULTS

A total of 11 652 patients were included in the analysis. Median duration from surgery to radiation was 30 d. On multivariable regression, black race, larger tumor, gross-total resection, methyguanine-methyl transferase (MGMT+), and treatment at an academic facility were associated with a duration &gt;30 d. On multivariable analysis, there were no significant differences when comparing start within 24 d to 25 to 30 d (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.90-1.01, P = .13) or &gt; 37 d (HR 0.97, 95% CI 0.91-1.03, P = .26), although a small OS improvement was seen if initiated within 31 to 37 d (HR 0.93, 95% CI 0.88-0.99, P = .02).

CONCLUSION

There was no clear association between duration from surgery to initiation of chemoradiation on OS.

Early tumor growth between initial resection and radiotherapy of glioblastoma: incidence and impact on clinical outcomes

Early tumor growth, or increased contrast-enhancing tumor not related to evolving post-surgical injury, in the interval between surgical resection and initiation of radiotherapy has implications for treatment planning and clinical outcomes. In this study we evaluated the incidence of early tumor growth, correlated tumor growth with survival outcome measures, and assessed predictors of early tumor growth in glioblastoma. We reviewed the records of patients with newly-diagnosed glioblastoma who underwent surgical resection and chemoradiotherapy at our institution. Patients with preoperative, immediate postoperative, and preradiotherapy MRI were included. Conventional MRI and DWI features were assessed. The correlation between early tumor growth and extent of resection with survival was assessed with Kaplan-Meier analysis. Logistic regression was carried out to evaluate predictors of early tumor growth. Of 140 included patients, sixty-seven cases (48%) had new or increased contrast enhancement attributed to early tumor growth. Median progression free survival (PFS) and overall survival (OS) were shorter in patients with early tumor growth compared to those without early tumor growth (p < 0.001 for both). Additionally, PFS and OS were longer in patients who underwent gross total resection of enhancing tumor (p = 0.016 and <0.001, respectively). Of the evaluated predictors of early growth, subtotal resection was most likely to result in early growth (p < 0.001). Imaging evidence of early tumor growth is often observed at preradiotherapy MRI and is associated with shorter survival. Gross total resection of contrast enhancing tumor decreases likelihood of early tumor growth.

Impact of interim progression during the surgery-to-radiotherapy interval and its predictors in glioblastoma treated with temozolomide-based radiochemotherapy

This study was designed to investigate the impact of interim progression of disease (PD) during the surgery-to-radiotherapy interval (SRI) and its predictors in glioblastoma based on MRIs. A total of 222 patients were planned for radiotherapy (RT) and 166 of them were evaluable for the presence of interim PD by 2 separate MRIs. The size criteria from the updated Response Assessment in Neuro-Oncology criteria was adopted to determine interim PD. 32 (19.3%) patients experienced interim PD, and their median survival (MS) was shorter than patients without PD in univariate (11.3 vs. 19.6 months, p < 0.001) and multivariate analysis (HR 2.237, 95% CI 1.367-3.660, p = 0.002). The volume of residual enhancing tumor (p = 0.003) and prolongation of the SRI (p = 0.004) were significant predictors of interim PD. Every 1-cc increase in residual enhancing tumor and every 1-day prolongation of the SRI significantly increased the risk of interim PD by 3.9% (p = 0.003) and 8.1% (p = 0.004), respectively. A significant portion of patients demonstrate interim PD during SRI and these patients have poor prognosis. The presence of interim PD should be concerned as a significant confounding factor for stratification in future clinical trials. A baseline pre-RT MRI is essential for accurate disease evaluation and RT-target delineation, especially in patients with larger residual disease after surgery and prolonged SRI due to the high risk of interim PD.

Molecular Diagnostics of Gliomas Using Next Generation Sequencing of a Glioma-Tailored Gene Panel

Current classification of gliomas is based on histological criteria according to the World Health Organization (WHO) classification of tumors of the central nervous system. Over the past years, characteristic genetic profiles have been identified in various glioma types. These can refine tumor diagnostics and provide important prognostic and predictive information. We report on the establishment and validation of gene panel next generation sequencing (NGS) for the molecular diagnostics of gliomas. We designed a glioma-tailored gene panel covering 660 amplicons derived from 20 genes frequently aberrant in different glioma types. Sensitivity and specificity of glioma gene panel NGS for detection of DNA sequence variants and copy number changes were validated by single gene analyses. NGS-based mutation detection was optimized for application on formalin-fixed paraffin-embedded tissue specimens including small stereotactic biopsy samples. NGS data obtained in a retrospective analysis of 121 gliomas allowed for their molecular classification into distinct biological groups, including (i) isocitrate dehydrogenase gene (IDH) 1 or 2 mutant astrocytic gliomas with frequent α-thalassemia/mental retardation syndrome X-linked (ATRX) and tumor protein p53 (TP53) gene mutations, (ii) IDH mutant oligodendroglial tumors with 1p/19q codeletion, telomerase reverse transcriptase (TERT) promoter mutation and frequent Drosophila homolog of capicua (CIC) gene mutation, as well as (iii) IDH wildtype glioblastomas with frequent TERT promoter mutation, phosphatase and tensin homolog (PTEN) mutation and/or epidermal growth factor receptor (EGFR) amplification. Oligoastrocytic gliomas were genetically assigned to either of these groups. Our findings implicate gene panel NGS as a promising diagnostic technique that may facilitate integrated histological and molecular glioma classification.

(Pro)renin receptor is crucial for glioma development via the Wnt/β-catenin signaling pathway

OBJECTIVE The (pro)renin receptor (PRR) plays an essential role in the early development of the central nervous system by activating the Wnt/β-catenin signaling pathway. The authors investigated the potential role of the PRR in the pathogenesis of glioma. METHODS The authors performed immunohistochemical analysis to detect both the PRR and isocitrate dehydrogenase 1 with mutations involving arginine 132 ( IDH1^R132H) in paraffin sections of 31 gliomas. Expression of the PRR and Wnt pathway components in cultured human glioma cell lines (U251MG, U87MG, and T98G) was measured using Western blotting. The effects of PRR short interfering RNA (siRNA) on glioma cell proliferation (WST-1 assay and direct cell counting) and apoptosis (flow cytometry and the caspase-3 assay) were also examined. RESULTS PRR expression was significantly higher in glioblastoma than in normal tissue or in lower grade glioma, regardless of IDH1^R132H mutation. PRR expression was also higher in human glioblastoma cell lines than in human astrocytes. PRR expression showed a significant positive correlation with the Ki-67 labeling index, while it had a significant negative correlation with the survival time of glioma patients. Treatment with PRR siRNA significantly reduced expression of Wnt2, activated β-catenin, and cyclin D1 by human glioblastoma cell lines, and it reduced the proliferative capacity of these cell lines and induced apoptosis. CONCLUSIONS This is the first evidence that the PRR has an important role in development of glioma by aberrant activation of the Wnt/β-catenin signaling pathway. This receptor may be both a prognostic marker and a therapeutic target for glioma.