Subventricular zone involvement at recurrence is a strong predictive factor of outcome following high grade glioma reirradiation

Therapeutic and prognostic impact of target volume delineation in postoperative radiotherapy for high-grade glioma patients with subventricular zone involvement

OBJECTIVE

This study aimed to analyze the effect of target volumes for radiotherapy and dose on the prognosis of high-grade glioma (HGG) patients when the tumor involves the subventricular zone (SVZ), and to provide a reference for postoperative target volume delineation in HGG patients with SVZ involvement.

METHODS

The clinical and pathological data were collected from 50 HGG patients with SVZ involvement were collected in the Department of Neurosurgery of the First Affiliated Hospital of Soochow University during the period from January 1, 2017 to December 31, 2020. The average dose (Dmean) of the whole ipsilateral and contralateral SVZs as well as the V45Gy and V60Gy of the whole ipsilateral SVZs of the tumor were derived from the dose-volume histograms (DVH). The Kaplan-Meier analysis was applied to compare the survival differences between groups under different factors. The Cox proportional risk regression model was used to analyze the influencing factors of progression-free survival (PFS) and overall survival (OS). The correlation between the size of the ipsilateral SVZ target area range and the progression pattern was tested by chi-square test.

RESULTS

Univariate analysis revealed that the potential predictors of PFS of HGG patients with tumor involvement in SVZ were as follows: multiple lesions, tumor size > 3.5 cm and total resection; the potential predictors of OS were multiple lesions, surgical approaches to the lateral ventricles and the dose of contralateral SVZ > 37.33 Gy. Multibariate analysis showed that tumor size > 3.5 cm and total resection were the independent prognostic factors of PFS; multiple lesions was the independent prognostic factors of OS. The Kaplan-Meier method showed that the median PFS and OS of HGG patients with V60Gy ≥ 50% was higher than that of patients with V60Gy < 50% but the difference was not statistically significant. Subgroup analysis showed that patients with V60Gy ≥ 50% had significantly higher PFS in the age < 60 years subgroup (P = 0.006), WHO IV grade (P = 0.006), and surgical penetration of the lateral ventricle subgroup (P = 0.034) than in the V60Gy < 50%. Patients with V60Gy ≥ 50% had significantly higher OS in the WHO IV grade subgroup (P = 0.035), surgically penetrated lateral ventricle subgroup (P = 0.008), IDH1 wild-type subgroup (P = 0.012), and MGMT unmethylated subgroup (P = 0.047) than in V60Gy < 50%. A volume of ≥ 50% of the ipsilateral SVZ receiving a 60 Gy irradiation dose improves local control and reduces the risk of local recurrence in patients with SVZ involvement in HGG.

CONCLUSIONS

For SVZ-involved HGG patients, the whole ipsilateral SVZ receiving 60 Gy irradiation dose in ≥ 50% of the volume prolonged PFS in those with age < 60 years, WHO IV grade and surgically penetrating lateral ventricles and prolonged OS in those with WHO IV grade, surgically penetrating lateral ventricles, IDH1 wild-type and MGMT unmethylated.

Targeting the neural stem cells in subventricular zone for the treatment of glioblastoma: an update from preclinical evidence to clinical interventions

BACKGROUND

Glioblastoma is one of the most common and aggressive adult brain tumors. The conventional treatment strategy, surgery combined with chemoradiotherapy, did not change the fact that the recurrence rate was high and the survival rate was low. Over the years, accumulating evidence has shown that the subventricular zone has an important role in the recurrence and treatment resistance of glioblastoma. The human adult subventricular zone contains neural stem cells and glioma stem cells that are probably a part of reason for therapy resistance and recurrence of glioblastoma.

MAIN BODY

Over the years, both bench and bedside evidences strongly support the view that the presence of neural stem cells and glioma stem cells in the subventricular zone may be the crucial factor of recurrence of glioblastoma after conventional therapy. It emphasizes the necessity to explore new therapy strategies with the aim to target subventricular zone to eradicate neural stem cells or glioma stem cells. In this review, we summarize the recent preclinical and clinical advances in targeting neural stem cells in the subventricular zone for glioblastoma treatment, and clarify the prospects and challenges in clinical application.

CONCLUSIONS

Although there remain unresolved issues, current advances provide us with a lot of evidence that targeting the neural stem cells and glioma stem cells in subventricular zone may have the potential to solve the dilemma of glioblastoma recurrence and treatment resistance.

New Enhancement beyond Radiation Field Improves Survival Prediction in Patients with Post-Treatment High-Grade Glioma

The imaging signs which can accurately predict survival prognosis after standard treatment of high-grade glioma (HGG) are highly desirable. This study aims to explore the role of new enhancement beyond radiation field (NERF) in the survival prediction in patients with post-treatment HGG. The present study included 142 pathologically confirmed HGG patients who had received standard treatment. NERF, as well as other conventional MR findings and clinical variables, were included in univariate and multivariate analyses for evaluating their impactions on progression-free survival (PFS) and overall survival (OS). Univariate analysis showed that histological grade (p=0.008) and NERF (p=0.001) were the prognostic variables for poor PFS, whereas histological grade (p=0.017), NERF (p=0.001), and new subventricular zone enhancement (nSVZE) (p=0.001) were prognostic variables for poor OS. The multivariate analysis showed that NERF (HR 3.93; 95% CI 1.93-8.01; p=0.001) and nSVZE (HR 3.92; 95% CI 1.95-7.89; p=0.001) were the prognostic variables for poor OS. However, only nSVZE was (HR 3.29; 95% CI 2.04-5.28; p=0.001) the prognostic variable for poor PFS. When combining the NERF with the clinical and other MR variables, the highest AUC (0.924) and specificity (0.899) for predicting poor OS were achieved. The location of new developed enhancements relevant to high dose radiation field appears to be the main determinant of their prognostic value. Our results suggest that the new enhancement beyond radiation field can improve the survival prediction in patients with HGG after standard treatment.

HAUSP promoted the growth of glioma cells in vitro and in vivo via stabilizing NANOG

OBJECTIVE

To investigate the role and mechanisms of HAUSP (Herpesvirus Associated Ubiquitin Specific Protease) and NANOG in pathogenesis of malignant human gliomas progression.

METHODS

Lentivirus-mediated HAUSP over-expression and RNAiHAUSP mediated HAUSP down-regulation were established in the glioma cells (U87 and U251 cell lines). Firstly, Real-time qPCR, western-blot (WB) and immunofluorescence staining were performed to detect mRNA levels, protein expressions and deposition of HAUSP and NANOG in the glioma cells, respectively. Then cell proliferation, invasion, apoptosis and xenograft tumor growth in nude mice were assessed by using cell counting kit-8 (CCK-8) assay, transwell assay, flow cytometry (FCM) and Hematoxylin-Eosin (HE) staining.

RESULTS

We first demonstrated HAUSP was significantly increased in lentivirus- mediated HAUSP over-expression cells compared to the Control group. HAUSP over-expression could upregulate genes involved in proliferation and invasion such as NANOG. However, the mRNA of NANOG had no significant changes. Similarly, in RNAiHAUSP mediated HAUSP down-regulation group, HAUSP were significantly decreased compared to the Control group. Simultaneously, NANOG protein were decreased significantly, which decreased the proliferation and invasion, increased the apoptosis rate of glioma cells. Finally, low expression of HAUSP could suppress xenograft tumors growth in nude mice in different periods.

CONCLUSION

This study revealed that HAUSP-NANOG pathway is a key target to inhibit glioma cells proliferation, and NANOG play important role in the formation and evolution of glioma cells. The regulation of HAUSP could change the biological activity of glioma cells through regulate NANOG expression.

Risk Factors for Early Mortality Among Patients with Glioma: A Population-Based Study

OBJECTIVE

The present study evaluated the early death and factors associated with early mortality in patients with glioma.

METHODS

The data used for analysis in the present study was extracted from the Surveillance, Epidemiology, and End Results data set.

RESULTS

A total of 58,700 patients with glioma were enrolled in the present study. The proportion of patient death within 1 month and 3 months after the diagnosis was 9.24% and 19.15% for all patients, respectively. The factors significantly associated with death within 1 month after tumor resection on multivariate analysis included age at diagnosis, year of diagnosis, tumor location, histological features, tumor size, and the absence of gross total resection, radiotherapy, and chemotherapy. We also observed similar findings in the evaluation of the factors associated with 3-month mortality.

CONCLUSION

The early deaths rates, including 1 and 3 months after tumor resection in patients with glioma, have decreased slightly during the previous 40 years. The risk factors for early mortality included advanced age, male sex, tumor located in the lateral ventricle, cerebellum, or brainstem, receipt of biopsy only, no chemotherapy or radiotherapy, and specific histopathological types.

Impact on survival of early tumor growth between surgery and radiotherapy in patients with de novo glioblastoma

PURPOSE

Systematic pre-radiotherapy MRI in patients with newly resected glioblastoma (OMS 2016) sometimes reveals tumor growth in the period between surgery and radiotherapy. We evaluated the relation between early tumor growth and overall survival (OS) with the aim of finding predictors of regrowth.

METHODS

Seventy-five patients from 25 to 84 years old (Median age 62 years) with preoperative, immediate postoperative, and preradiotherapy MRI were included. Volumetric measurements were made on each of the three MRI scans and clinical and molecular parameters were collected for each case.

RESULTS

Fifty-four patients (72%) had an early regrowth with a median contrast enhancement volume of 3.61 cm³-range 0.12-71.93 cm³. The median OS was 24 months in patients with no early tumor growth and 17.1 months in those with early tumor regrowth (p = 0.0024). In the population with initial complete resection (27 patients), the median OS was 25.3 months (19 patients) in those with no early tumor growth between surgery and radiotherapy compared to 16.3 months (8 patients) in those with tumor regrowth. In multivariate analysis, the initial extent of resection (p < 0.001) and the delay between postoperative MRI and preradiotherapy MRI (p < 0.001) were significant independent prognostic factors of regrowth and of poorer outcome.

CONCLUSIONS

We demonstrated that, in addition to the well known issue of incomplete resection, longer delays between surgery and adjuvant treatment is an independent factors of tumor regrowth and a risk factor of poorer outcomes for the patients. To overcome the delay factor, we suggest shortening the usual time between surgery and radiotherapy.

RND1 regulates migration of human glioblastoma stem-like cells according to their anatomical localization and defines a prognostic signature in glioblastoma

Despite post-operative radio-chemotherapy, glioblastoma systematically locally recurs. Tumors contacting the periventricular zone (PVZ) show earlier and more distant relapses than tumors not contacting the PVZ. Since glioblastoma stem-like cells (GSCs) have been proposed to play a major role in glioblastoma recurrence, we decided to test whether GSC migration properties could be different according to their anatomical location (PVZ+/PVZ–). For that purpose, we established paired cultures of GSCs from the cortical area (CT) and the PVZ of glioblastoma patient tumors. We demonstrated that PVZ GSCs possess higher migration and invasion capacities than CT GSCs. We highlighted specific transcriptomic profiles in PVZ versus CT populations and identified a down-regulation of the RhoGTPase, RND1 in PVZ GSCs compared to CT GSCs. Overexpression of RND1, dramatically inhibited PVZ GSC migration and conversely, downregulation of RND1 increased CT GSC migration. Additionally, transcriptomic analyses also revealed a down-regulation of RND1 in glioblastoma compared to normal brain. Using the glioblastoma TCGA database, low levels of RND1 were also shown to correlate with a decreased overall survival of patients. Finally, based on signaling pathways activated in patients with low levels of RND1, we identified an RND1^low signature of six genes (MET, LAMC1, ITGA5, COL5A1, COL3A1, COL1A2) that is an independent prognostic factor in glioblastoma. These findings contribute to explain the shorter time to progression of patients with PVZ involvement and, point out genes that establish the RND1^low signature as key targets genes to impede tumor relapse after treatment.