OH2 oncolytic virus: A novel approach to glioblastoma intervention through direct targeting of tumor cells and augmentation of anti-tumor immune responses

Glioblastoma (GBM), the deadliest central nervous system cancer, presents a poor prognosis and scant therapeutic options. Our research spotlights OH2, an oncolytic viral therapy derived from herpes simplex virus 2 (HSV-2), which demonstrates substantial antitumor activity and favorable tolerance in GBM. The extraordinary efficacy of OH2 emanates from its unique mechanisms: it selectively targets tumor cells replication, powerfully induces cytotoxic DNA damage stress, and kindles anti-tumor immune responses. Through single-cell RNA sequencing analysis, we discovered that OH2 not only curtails the proliferation of cancer cells and tumor-associated macrophages (TAM)-M2 but also bolsters the infiltration of macrophages, CD4+ and CD8+ T cells. Further investigation into molecular characteristics affecting OH2 sensitivity revealed potential influencers such as TTN, HMCN2 or IRS4 mutations, CDKN2A/B deletion and IDO1 amplification. This study marks the first demonstration of an HSV-2 derived OV's effectiveness against GBM. Significantly, these discoveries have driven the initiation of a phase I/II clinical trial (ClinicalTrials.gov: NCT05235074). This trial is designed to explore the potential of OH2 as a therapeutic option for patients with recurrent central nervous system tumors following surgical intervention.

Prognosis of glioblastoma patients improves significantly over time interrogating historical controls

BACKGROUND

Glioblastoma (GBM) is the most common devastating primary brain cancer in adults. In our clinical practice, median overall survival (mOS) of GBM patients seems increasing over time.

METHODS

To address this observation, we have retrospectively analyzed the prognosis of 722 newly diagnosed GBM patients, aged below 70, in good clinical conditions (i.e. Karnofsky Performance Status -KPS- above 70%) and treated in our department according to the standard of care (SOC) between 2005 and 2018. Patients were divided into two groups according to the year of diagnosis (group 1: from 2005 to 2012; group 2: from 2013 to 2018).

RESULTS

Characteristics of patients and tumors of both groups were very similar regarding confounding factors (age, KPS, MGMT promoter methylation status and treatments). Follow-up time was fixed at 24 months to ensure comparable survival times between both groups. Group 1 patients had a mOS of 19 months ([17.3-21.3]) while mOS of group 2 patients was not reached. The recent period of diagnosis was significantly associated with a longer mOS in univariate analysis (HR=0.64, 95% CI [0.51 - 0.81]), p < 0.001). Multivariate Cox analysis showed that the period of diagnosis remained significantly prognostic after adjustment on confounding factors (adjusted Hazard Ratio (aHR) 0.49, 95% CI [0.36-0.67], p < 0.001).

CONCLUSION

This increase of mOS over time in newly diagnosed GBM patients could be explained by better management of potentially associated non-neurological diseases, optimization of validated SOC, better management of treatments side effects, supportive care and participation in clinical trials.

Advancing glioblastoma treatment by targeting metabolism

Alterations in cellular metabolism are important hallmarks of glioblastoma(GBM). Metabolic reprogramming is a critical feature as it meets the higher nutritional demand of tumor cells, including proliferation, growth, and survival. Many genes, proteins, and metabolites associated with GBM metabolism reprogramming have been found to be aberrantly expressed, which may provide potential targets for cancer treatment. Therefore, it is becoming increasingly important to explore the role of internal and external factors in metabolic regulation in order to identify more precise therapeutic targets and diagnostic markers for GBM. In this review, we define the metabolic characteristics of GBM, investigate metabolic specificities such as targetable vulnerabilities and therapeutic resistance, as well as present current efforts to target GBM metabolism to improve the standard of care.

Survivors of infant atypical teratoid/rhabdoid tumors present with severely impaired cognitive functions especially for fluid intelligence and visual processing: data from the German brain tumor studies

BACKGROUND

The contribution of tumor type, multimodal treatment, and other patient-related factors upon long-term cognitive sequelae in infant brain tumor survivors remains undefined. We add our retrospective analysis of neuropsychological and quality of survival (QoS) outcome data of survivors of atypical teratoid/rhabdoid tumors (ATRT) and extracranial malignant rhabdoid tumors of the soft tissues (eMRT) and kidneys (RTK) treated within the same framework. Neuropsychological data from children with ATRT were compared to data from children with non-irradiated low-grade glioma (LGG).

PATIENTS AND METHODS

Following surgery, patients (0-36 months at diagnosis) had received radio-chemotherapy (up to 54 Gy; ATRT: n = 13; eMRT/RTK: n = 7), chemotherapy only (LGG: n = 4; eMRT/RTK: n = 1) or had been observed (LGG: n = 11). Neuropsychological evaluation employing comparable tests was performed at median 6.8 years (ATRT), 6.6 years (eMRT/RTK), and 5.2 years (LGG) post diagnosis.

RESULTS

We detected sequelae in various domains for all tumor types. Group comparison showed impairments, specifically in fluid intelligence (p = .041; d = 1.11) and visual processing (p = .001; d = 2.09) in ATRT patients when compared to LGG patients. Results for psychomotor speed and attention abilities were significantly below the norm for both groups (p < .001-.019; d = 0.79-1.90). Diagnosis predicted impairments of cognitive outcome, while sex- and age-related variables did not. QoS outcome for all rhabdoid patients displayed impairments mainly in social (p = .008; d = 0.74) and school functioning (p = .048; d = 0.67), as well as lower overall scores in psychosocial functioning (p = .023; d = 0.78) and quality of life (p = .006; d = 0.79) compared to healthy controls.

CONCLUSION

Survivors of infant ATRT experience various late effects in cognition and QoS following multimodal treatment, while infant LGG patients without radiotherapy demonstrated comparable impairments in psychomotor and attention abilities. Early onset and multimodal treatment of rhabdoid tumors require close monitoring of neuropsychological and QoS sequelae.

Predicting neuropsychological late effects in pediatric brain tumor survivors using the Neurological Predictor Scale and the Pediatric Neuro-Oncology Rating of Treatment Intensity

OBJECTIVE

The Neurological Predictor Scale (NPS) quantifies cumulative exposure to tumor- and treatment-related neurological risks. The Pediatric Neuro-Oncology Rating of Treatment Intensity (PNORTI) measures the intensity of different treatment modalities, but research is needed to establish whether it is associated with late effects. This study evaluated the predictive validity of the NPS and PNORTI for neuropsychological outcomes in pediatric brain tumor survivors.

METHOD

A retrospective chart review was completed of pediatric brain tumor survivors (PBTS) (n = 161, Mage = 13.47, SD = 2.80) who were at least 2 years from the end of tumor-directed treatment. Attention, intellectual functioning, perceptual reasoning, processing speed, verbal reasoning, and working memory were analyzed in relation to the NPS and PNORTI.

RESULTS

NPS scores ranged from 1 to 11 (M = 5.57, SD = 2.27) and PNORTI scores ranged from 1 (n = 101; 62.7%) to 3 (n = 18; 11.2%). When controlling for age, sex, SES factors, and time since treatment, NPS scores significantly predicted intellectual functioning [F(7,149) = 12.86, p < .001, R2 = .38] and processing speed [F(7,84) = 5.28, p < .001, R2 = .31]. PNORTI scores did not significantly predict neuropsychological outcomes.

CONCLUSIONS

The findings suggest that the NPS has value in predicting IF and processing speed above-and-beyond demographic variables. The PNORTI was not associated with neuropsychological outcomes. Future research should consider establishing clinical cutoff scores for the NPS to help determine which survivors are most at risk for neuropsychological late effects and warrant additional assessment.

Neuro-oncological research output in Africa: a scoping review of primary brain tumors

BACKGROUND

There is evidence that individuals of African ancestry, particularly those residing in Africa, suffer from an unfortunate amount of under-representation in cancer research worldwide.

AIM

We aimed to analyze current research output and potentially predict future trends in neuro-oncological research in Africa. Investigating deficits in the field will assist in identifying top-performing countries, which ones face challenges, and how to solve them. Therefore, targeted interventions can be applied to overcome these challenges.

METHODS

We conducted a systematic computer-based search on the following databases (PubMed, Scopus, Web of Science, and Embase) for research articles related to the neuro-oncological field in Africa. We aimed to retrieve any article published in the period between 1 January 2000 and 10 January 2023.

RESULTS

We included 200 eligible articles in our study. The output of neuro-oncological research has been increasing over the past two decades, peaking in 2019. Among the included articles, clinical practice issues constituted the majority (80%), while public health-related topics accounted for 20% of the publications. Regarding the type of neurological tumor, neuroblastoma was the most common, with 26 articles (13%), meningioma with 21 (10.5%), and glioma with 16 articles (8%).

CONCLUSION

The interest in African neuro-oncological research is increasing. Hence, there is a need for ongoing efforts to address issues with clinical practice and public health related to neurological tumors in the continent. Future studies should concentrate on filling in knowledge gaps and investigating novel methods for neuro-oncological conditions that affect African populations in terms of prevention, diagnosis, treatment, and management strategies.

Anti-EGFR ScFv functionalized exosomes delivering LPCAT1 specific siRNAs for inhibition of lung cancer brain metastases

Brain metastasis (BM) is one of the leading causes of cancer-related deaths in patients with advanced non-small cell lung cancer (NSCLC). However, limited treatments are available due to the presence of the blood-brain barrier (BBB). Upregulation of lysophosphatidylcholine acyltransferase 1 (LPCAT1) in NSCLC has been found to promote BM. Conversely, downregulating LPCAT1 significantly suppresses the proliferation and metastasis of lung cancer cells. In this study, we firstly confirmed significant upregulation of LPCAT1 in BM sites compared to primary lung cancer by analyzing scRNA dataset. We then designed a delivery system based on a single-chain variable fragment (scFv) targeting the epidermal growth factor receptor (EGFR) and exosomes derived from HEK293T cells to enhance cell-targeting capabilities and increase permeability. Next, we loaded LPCAT1 siRNA (siLPCAT1) into these engineered exosomes (exoscFv). This novel scFv-mounted exosome successfully crossed the BBB in an animal model and delivered siLPCAT1 to the BM site. Silencing LPCAT1 efficiently arrested tumor growth and inhibited malignant progression of BM in vivo without detectable toxicity. Overall, we provided a potential platform based on exosomes for RNA interference (RNAi) therapy in lung cancer BM.

Rational and design of prophylactic cranial irradiation (PCI) and brain MRI surveillance versus brain MRI surveillance alone in patients with limited-stage small cell lung cancer achieving complete remission (CR) of tumor after chemoradiotherapy: a multicenter prospective randomized study

BACKGROUND

Prophylactic cranial irradiation (PCI) is part of standard care in limited-stage small cell lung cancer (SCLC) at present. As evidence from retrospective studies increases, the benefits of PCI for limited-stage SCLC are being challenged.

METHODS

A multicenter, prospective, randomized controlled study was designed. The key inclusion criteria were: histologically or cytologically confirmed small cell carcinoma, age ≥ 18 years, KPS ≥ 80, limited-stage is defined as tumor confined to one side of the chest including ipsilateral hilar, bilateral mediastinum and supraclavicular lymph nodes, patients have received definitive thoracic radiotherapy (regardless of the dose-fractionation of radiotherapy used) and chemotherapy, evaluated as complete remission (CR) of tumor 4-6 weeks after the completion of chemo-radiotherapy. Eligible patients will be randomly assigned to two arms: (1) PCI and brain MRI surveillance arm, receiving PCI (2.5 Gy qd to a total dose of 25 Gy in two weeks) followed by brain MRI surveillance once every three months for two years; (2) brain MRI surveillance alone arm, undergoing brain MRI surveillance once every three months for two years. The primary objective is to compare the 2-year brain metastasis-free survival (BMFS) rates between the two arms. Secondary objectives include 2-year overall survival (OS) rates, intra-cranial failure patterns, 2-year progression-free survival rates and neurotoxicity. In case of brain metastasis (BM) detect during follow-up, stereotactic radiosurgery (SRS) will be recommended if patients meet the eligibility criteria.

DISCUSSION

Based on our post-hoc analysis of a prospective study, we hypothesize that in limited-stage SCLC patients with CR after definitive chemoradiotherapy, and ruling out of BM by MRI, it would be feasible to use brain MRI surveillance and omit PCI in these patients. If BM is detected during follow-up, treatment with SRS or whole brain radiotherapy does not appear to have a detrimental effect on OS. Additionally, this approach may reduce potential neurotoxicity associated with PCI.

Defining interventions and metrics to improve diversity in CNS clinical trial participation: A SNO and RANO effort

Despite major strides in cancer research and therapy, these advances have not been equitable across race and ethnicity. Historically marginalized groups (HMG) are more likely to have inadequate preventive screening, increased delays in diagnosis, and poor representation in clinical trials. Notably, Black, Hispanic, and Indigenous people represent 30% of the population but only 9% of oncology clinical trial participants. As a result, HMGs lack equitable access to novel therapies, contradicting the principle of distributive justice, as enshrined in the Belmont report, which demands the equitable selection of subjects in research involving human subjects. The lack of clinical trial diversity also leads to low generalizability and potentially harmful medical practices. Specifically, patients with brain cancer face unique barriers to clinical trial enrollment and completion due to disease-specific neurologic and treatment-induced conditions. Collectively, the intersection of these disease-specific conditions with social determinants of health fosters a lack of diversity in clinical trials. To ameliorate this disparity in neuro-oncology clinical trial participation, we present interventions focused on improving engagement of HMGs. Proposals range from inclusive trial design, decreasing barriers to care, expanding trial eligibility, access to tumor profiling for personalized medical trials, setting reasonable metrics and goals for accrual, working with patient community stakeholders, diversifying the neuro-oncology workforce, and development of tools to overcome biases with options to incentivize equity. The diversification of participation amongst neuro-oncology clinical trials is imperative. Equitable access and inclusion of HMG patients with brain tumors will not only enhance research discoveries but will also improve patient care.

Impact of glioma peritumoral edema, tumor size, and tumor location on alternating electric fields (AEF) therapy in realistic 3D rat glioma models: a computational study

Objective.Alternating electric fields (AEF) therapy is a treatment modality for patients with glioblastoma. Tumor characteristics such as size, location, and extent of peritumoral edema may affect the AEF strength and distribution. We evaluated the sensitivity of the AEFs in a realistic 3D rat glioma model with respect to these properties.Approach.The electric properties of the peritumoral edema were varied based on calculated and literature-reported values. Models with different tumor composition, size, and location were created. The resulting AEFs were evaluated in 3D rat glioma models.Main results.In all cases, a pair of 5 mm diameter electrodes induced an average field strength >1 V cm-1. The simulation results showed that a negative relationship between edema conductivity and field strength was found. As the tumor core size was increased, the average field strength increased while the fraction of the shell achieving >1.5 V cm-1decreased. Increasing peritumoral edema thickness decreased the shell's mean field strength. Compared to rostrally/caudally, shifting the tumor location laterally/medially and ventrally (with respect to the electrodes) caused higher deviation in field strength.Significance.This study identifies tumor properties that are key drivers influencing AEF strength and distribution. The findings might be potential preclinical implications.

A more efficient method for generating glioblastoma-multiforme model in mice using genome editing technology

The elucidation of the properties of malignant glioma and development of therapeutic methods require glioblastoma-multiforme mice model with characteristics such as invasiveness, multinuclearity, and ability for mitosis. A previous study has shown that overexpression of active HRas (HRasL61) in neural stem/progenitor cells (NSCs) isolated from p53 knockout (KO) mice could induce glioma-initiating cells (GICs). The orthotopically transplantation of 10 cells into the forebrain of immunodeficient mice resulted in the development of glioblastoma multiforme-like malignant brain tumors. In this study, we successfully induced GICs from wild-type fetal NSCs. Using CRISPR/Cas9, we obtained p53 KO NSCs. HRasL61 was additionally overexpressed in p53 KO NSCs. p53-/HRasL61+ cells were cloned and then transplanted into immunodeficient mice. p53-/HRasL61+ cells formed glioblastoma multiforme-like tumors. Further, GIC markers were strongly expressed in p53-/HRasL61+ cells. Therefore, p53-/HRasL61+ cell is an induced GIC. A CRISPR/Cas9-based method for inducing GIC is much more efficient than a KO mice-based method. This study provides a promising framework for easily creating glioblastoma model in mice.

The safety and accuracy of intratumoral catheter placement to infuse viral immunotherapies in children with malignant brain tumors: a multi-institutional study

OBJECTIVE

Relatively little is known about the safety and accuracy of catheter placement for oncolytic viral therapy in children with malignant brain tumors. Accordingly, this study combines data from two phase I clinical trials that employed viral immunotherapy across two institutions to describe the adverse event profile, safety, and accuracy associated with the stereotactic placement and subsequent removal of intratumoral catheters.

METHODS

Children with progressive/recurrent supratentorial malignant tumors were enrolled in two clinical trials (NCT03043391 and NCT02457845) and treated with either the recombinant polio:rhinovirus (lerapolturev) or the genetically modified oncolytic herpesvirus (G207). Age, sex, race, tumor diagnosis, and tumor location were analyzed. Events related to the catheter placement or removal were categorized. A catheter that was either pulled back or could not be used was defined as "misplaced." Neuronavigation software was used to analyze the accuracy of catheter placement for NCT03043391. Descriptive statistics were performed.

RESULTS

Nineteen patients were treated across the two completed trials with a total of 49 catheters. The mean ± SD (range) age was 14.1 ± 3.6 (7-19) years. All tumors were grade 3 or 4 gliomas. Nonlobar catheter tip placement included the corpus callosum, thalamus, insula, and cingulate gyrus. Six of 19 patients (31.6%) had minor hemorrhage noted on CT; however, no patients were symptomatic and/or required intervention related to these findings. One of 19 patients had a delayed CSF leak after catheter removal that required oversewing of the surgical site. No patients developed infection or a neurological deficit. In 7 patients with accuracy data, the mean ± SD distance of the planned trajectory (PT) to the catheter tip was 1.57 ± 1.6 mm, the mean angle of the PT to the catheter was 2.43° ± 2.1°, and the greatest distance of PT to the catheter in the parallel plane was 1.54 ± 1.5 mm. Three of 49 (6.1%) catheters were considered misplaced.

CONCLUSIONS

Although instances of minor hemorrhage were encountered, they were clinically asymptomatic. One of 49 catheters required intervention for a CSF leak. Congruent with previous studies in the literature, the stereotactic placement of catheters in these pediatric tumor patients was accurate with approximately 95% of catheters having been adequately placed.

Chat-GPT on brain tumors: An examination of Artificial Intelligence/Machine Learning's ability to provide diagnoses and treatment plans for example neuro-oncology cases

OBJECTIVE

Assess the capabilities of ChatGPT-3.5 and 4 to provide accurate diagnoses, treatment options, and treatment plans for brain tumors in example neuro-oncology cases.

METHODS

ChatGPT-3.5 and 4 were provided with twenty example neuro-oncology cases of brain tumors, all selected from medical textbooks. The artificial intelligence programs were asked to give a diagnosis, treatment option, and treatment plan for each of these twenty example cases. Team members first determined in which cases ChatGPT-3.5 and 4 provided the correct diagnosis or treatment plan. Twenty neurosurgeons from the researchers' institution then independently rated the diagnoses, treatment options, and treatment plans provided by both artificial intelligence programs for each of the twenty example cases, on a scale of one to ten, with ten being the highest score. To determine whether the difference between the scores of ChatGPT-3.5 and 4 was statistically significant, a paired t-test was conducted for the average scores given to the programs for each example case.

RESULTS

In the initial analysis of correct responses, ChatGPT-4 had an accuracy of 85% for its diagnoses of example brain tumors and an accuracy of 75% for its provided treatment plans, while ChatGPT-3.5 only had an accuracy of 65% and 10%, respectively. The average scores given by the twenty independent neurosurgeons to ChatGPT-4 for its accuracy of diagnosis, provided treatment options, and provided treatment plan were 8.3, 8.4, and 8.5 out of 10, respectively, while ChatGPT-3.5's average scores for these categories of assessment were 5.9, 5.7, and 5.7. These differences in average score are statistically significant on a paired t-test, with a p-value of less than 0.001 for each difference.

CONCLUSIONS

ChatGPT-4 demonstrates great promise as a diagnostic tool for brain tumors in neuro-oncology, as attested to by the program's performance in this study and its assessment by surveyed neurosurgeon reviewers.

Post-ictal changes presenting as late pseudoprogression on MRI and PET in a patient with diffuse glioma: Case report and brief literature review

Following completion of adjuvant radiation and chemotherapy imaging surveillance forms a major role in the management of diffuse gliomas. The primary role of imaging is to detect recurrences earlier than clinical symptomatology. Magnetic resonance imaging (MRI) is considered the gold standard in follow-up protocols owing to better soft tissue delineation and multiparametric nature. True recurrence can often mimic treatment-related changes, it is of paramount importance to differentiate between the two entities as the clinical course is divergent. Addition of functional sequences like perfusion, spectroscopy and metabolic imaging can provide further details into the microenvironment. In equivocal cases, a follow-up short interval imaging might be obtained to settle the diagnostic dilemma. Here, we present a patient with diagnosis of recurrent oligodendroglioma treated with adjuvant chemoradiation, presenting with seizures five years post-completion of chemotherapy for recurrence. On MRI, subtle new onset gyral thickening of the left frontal region with mild increase in perfusion and patchy areas of raised choline. FET-PET (fluoro-ethyltyrosine) showed an increased tumour-to-white matter (T/Wm) ratio favouring tumour recurrence. Based on discussion in a multi-disciplinary joint clinic, short interval follow-up MRI was undertaken at two months showing decrease in gyral thickening and resolution of enhancing areas in left frontal lobe. Repeat imaging one year later demonstrated stable disease status without further new imaging findings. Given the changes resolving completely without any anti-tumoral intervention, we conclude this to be peri-ictal pseudoprogression, being the second such case described in India.

Clinical characteristics and prognostic factors in nasopharyngeal carcinoma with brain metastasis: A retrospective, single-center study

BACKGROUND

Brain metastasis is rare in nasopharyngeal carcinoma (NPC), with only anecdotal cases reported. Conducting a systematic study is crucial for improving the management of these patients.

MATERIALS AND METHODS

Forty-one patients with brain metastasis were retrospectively included between February 2000 and February 2023. The clinical characteristics and treatment information of patients were analyzed. Overall survival (OS) was estimated by Kaplan-Meier survival analysis, and Cox proportional hazard regression analysis was performed to explore prognostic factors.

RESULTS

The median OS for patients was 11.2 months, with a 3-year OS rate of 16.3%. The number of extracranial metastatic organs (HR = 5.533, P = 0.041) and the response of extracranial tumors to treatment (HR = 0.079, P = 0.003) were independent prognostic factors in the cohort.

CONCLUSIONS

Brain metastasis in NPC is a devastating condition that commonly occurs through hematogenous dissemination. Systemic therapy remains fundamental treatment, while local therapy for brain metastases may further improve survival in selected patients.

Identification of genetic modifiers enhancing B7-H3-targeting CAR T cell therapy against glioblastoma through large-scale CRISPRi screening

BACKGROUND

Glioblastoma multiforme (GBM) is a highly aggressive brain tumor with a poor prognosis. Current treatment options are limited and often ineffective. CAR T cell therapy has shown success in treating hematologic malignancies, and there is growing interest in its potential application in solid tumors, including GBM. However, current CAR T therapy lacks clinical efficacy against GBM due to tumor-related resistance mechanisms and CAR T cell deficiencies. Therefore, there is a need to improve CAR T cell therapy efficacy in GBM.

METHODS

We conducted large-scale CRISPR interference (CRISPRi) screens in GBM cell line U87 MG cells co-cultured with B7-H3 targeting CAR T cells to identify genetic modifiers that can enhance CAR T cell-mediated tumor killing. Flow cytometry-based tumor killing assay and CAR T cell activation assay were performed to validate screening hits. Bioinformatic analyses on bulk and single-cell RNA sequencing data and the TCGA database were employed to elucidate the mechanism underlying enhanced CAR T efficacy upon knocking down the selected screening hits in U87 MG cells.

RESULTS

We established B7-H3 as a targetable antigen for CAR T therapy in GBM. Through large-scale CRISPRi screening, we discovered genetic modifiers in GBM cells, including ARPC4, PI4KA, ATP6V1A, UBA1, and NDUFV1, that regulated the efficacy of CAR T cell-mediated tumor killing. Furthermore, we discovered that TNFSF15 was upregulated in both ARPC4 and NDUFV1 knockdown GBM cells and revealed an immunostimulatory role of TNFSF15 in modulating tumor-CAR T interaction to enhance CAR T cell efficacy.

CONCLUSIONS

Our study highlights the power of CRISPR-based genetic screening in investigating tumor-CAR T interaction and identifies potential druggable targets in tumor cells that confer resistance to CAR T cell killing. Furthermore, we devised targeted strategies that synergize with CAR T therapy against GBM. These findings shed light on the development of novel combinatorial strategies for effective immunotherapy of GBM and other solid tumors.

[A Case of Five Years Recurrence-Free Survival after Successful Multidisciplinary Treatment for Simultaneous Brain Metastasis and Heterochronic Small Intestinal Metastasis from Lung Cancer]

The patient was a 54-year-old male at the time of initial examination. He was aware of numbness and weakness in the left hemisphere of his body and came to see the hospital. He was diagnosed with brain metastasis of lung cancer and started treatment(cT2N0M1[Brain]). He underwent gamma knife for the head lesion and nivolumab for the lung lesion. The patient's lesions shrank with the success of the medical treatment, but recurred with small intestinal metastasis. He underwent a partial resection of the small intestine and was treated again with nivolumab, which resulted in a complete response. He is currently alive without recurrence. We have experienced a very rare case of recurrence-free survival after treatment for brain metastasis and small intestinal metastasis of lung cancer.

Early pseudoprogression and progression lesions in glioblastoma patients are both metabolically heterogeneous

The standard treatment in glioblastoma includes maximal safe resection followed by concomitant radiotherapy plus chemotherapy and adjuvant temozolomide. The first follow-up study to evaluate treatment response is performed 1 month after concomitant treatment, when contrast-enhancing regions may appear that can correspond to true progression or pseudoprogression. We retrospectively evaluated 31 consecutive patients at the first follow-up after concomitant treatment to check whether the metabolic pattern assessed with multivoxel MRS was predictive of treatment response 2 months later. We extracted the underlying metabolic patterns of the contrast-enhancing regions with a blind-source separation method and mapped them over the reference images. Pattern heterogeneity was calculated using entropy, and association between patterns and outcomes was measured with Cramér's V. We identified three distinct metabolic patterns-proliferative, necrotic, and responsive, which were associated with status 2 months later. Individually, 70% of the patients showed metabolically heterogeneous patterns in the contrast-enhancing regions. Metabolic heterogeneity was not related to the regions' size and only stable patients were less heterogeneous than the rest. Contrast-enhancing regions are also metabolically heterogeneous 1 month after concomitant treatment. This could explain the reported difficulty in finding robust pseudoprogression biomarkers.

Prognostic factors analysis of diffuse midline glioma

PURPOSE

This study retrospectively analyzes cases of diffuse midline glioma treated with radiotherapy, with the aim of investigating the prognosis of the tumor and its influencing factors.

METHODS

From January 2018 to November 2022, we treated 64 patients who were pathologically diagnosed with diffuse midline glioma. Among them, 41 underwent surgical resection, and 23 underwent biopsy procedures. All patients received postoperative radiotherapy. We followed up with the patients to determine the overall survival rate and conducted univariate and multivariate analyses on relevant indicators.

RESULTS

The median survival time for the entire patient group was 33.3 months, with overall survival rates of 92.9%, 75.4%, and 45.0% at 1 year, 2 years, and 3 years, respectively. Univariate and multivariate analyses indicated that older patients had a better prognosis.

CONCLUSION

Patient age is an independent prognostic factor for patients with diffuse midline glioma undergoing radiation therapy.

Comparison of ASL and DSC perfusion methods in the evaluation of response to treatment in patients with a history of treatment for malignant brain tumor

OBJECTIVE

Perfusion MRI is of great benefit in the post-treatment evaluation of brain tumors. Interestingly, dynamic susceptibility contrast-enhanced (DSC) perfusion has taken its place in routine examination for this purpose. The use of arterial spin labeling (ASL), a perfusion technique that does not require exogenous contrast material injection, has gained popularity in recent years. The aim of the study was to compare two different perfusion techniques, ASL and DSC, using qualitative and quantitative measurements and to investigate the diagnostic effectiveness of both. The fact that the number of patients is higher than in studies conducted with 3D pseudo-continious ASL (pCASL), the study group is heterogeneous as it consists of patients with both metastases and glial tumors, the use of 3D Turbo Gradient Spin Echo (TGSE), and the inclusion of visual (qualitative) assessment make our study unique.

METHODS

Ninety patients, who were treated for malignant brain tumor, were enrolled in the retrospective study. DSC Cerebral Blood Volume (CBV), Cerebral Blood Flow (CBF) and ASL CBF maps of each case were obtained. In qualitative analysis, the lesions of the cases were visually classified as treatment-related changes (TRC) and relapse/residual mass (RRT). In the quantitative analysis, three regions of interest (ROI) measurements were taken from each case. The average of these measurements was compared with the ROI taken from the contralateral white matter and normalized values (n) were obtained. These normalized values were compared across events.

RESULTS

Uncorrected DSC normalized CBV (nCBV), DSC normalized CBF (nCBF) and ASL nCBF values of RRT cases were higher than those of TRC cases (p < 0.001). DSC nCBV values were correlated with DSC nCBF (r: 0.94, p < 0.001) and correlated with ASL nCBF (r: 0.75, p < 0.001). Similarly, ASL nCBF was positively correlated with DSC nCBF (r: 0.79 p < 0.01). When the ROC curve parameters were evaluated, the cut-off values were determined as 1.211 for DSC nCBV (AUC: 0.95, 93% sensitivity, 82% specificity), 0.896 for DSC nCBF (AUC; 0.95, 93% sensitivity, 82% specificity), and 0.829 for ASL nCBF (AUC: 0.84, 78% sensitivity, 75% specificity). For qualitative evaluation (visual evaluation), inter-observer agreement was found to be good for ASL CBF (0.714), good for DSC CBF (0.790), and excellent for DSC CBV (0.822). Intra-observer agreement was also evaluated. For the first observer, good agreement was found in ASL CBF (0.626, 70% sensitive, 93% specific), in DSC CBF (0.713, 76% sensitive, 95% specific), and in DSC CBV (0.755, 87% sensitive - 88% specific). In the second observer, moderate agreement was found in ASL CBF (0.584, 61% sensitive, 97% specific) and DSC CBF (0.649, 65% sensitive, 100% specific), and excellent agreement in DSC CBV (0.800, 89% sensitive, 90% specific).

CONCLUSION

It was observed that uncorrected DSC nCBV, DSC nCBF and ASL nCBF values were well correlated with each other. In qualitative evaluation, inter-observer and intra-observer agreement was higher in DSC CBV than DSC CBF and ASL CBF. In addition, DSC CBV is found more sensitive, ASL CBF and DSC CBF are found more specific for both observers. From a diagnostic perspective, all three parameters DSC CBV, DSC CBF and ASL CBF can be used, but it was observed that the highest rate belonged to DSC CBV.

GRIK1 promotes glioblastoma malignancy and is a novel prognostic factor of poor prognosis

Primary tumors of the central nervous system (CNS) are classified into over 100 different histological types. The most common type of glioma is derived from astrocytes, and the most invasive glioblastoma (WHO IV) accounts for over 57% of these tumors. Glioblastoma (GBM) is the most common and fatal tumor of the CNS, with strong growth and invasion capabilities, which makes complete surgical resection almost impossible. Despite various treatment methods such as surgery, radiotherapy, and chemotherapy, glioma is still an incurable disease, and the median survival time of patients with GBM is shorter than 15 months. Thus, molecular mechanisms of GBM characteristic invasive growth need to be clarified to improve the poor prognosis. Glutamate ionotropic receptor kainate type subunit 1 (GRIK1) is essential for brain function and is involved in many mental and neurological diseases. However, GRIK1's pathogenic roles and mechanisms in GBM are still unknown. Single-nuclear RNA sequencing of primary and recurrent GBM samples revealed that GRIK1 expression was noticeably higher in the recurrent samples. Moreover, immunohistochemical staining of an array of GBM samples showed that high levels of GRIK1 correlated with poor prognosis of GBM, consistent with The Cancer Genome Atlas database. Knockdown of GRIK1 retarded GBM cells growth, migration, and invasion. Taken together, these findings show that GRIK1 is a unique and important component in the development of GBM and may be considered as a biomarker for the diagnosis and therapy in individuals with GBM.

[The importance and areas of modern supportive and early integrated palliative care in the treatment of brain tumor patients]

During the care of brain tumor patients, supportive care and palliation are carried out in an individualized manner, accompanied by adequate communication, in a multidisciplinary professional environment. In the case of brain tumor patients, the burden of symptoms resulting from the progression of the disease and the complications of treatments occur in a particularly high proportion. The supportive care of patients in a modern approach covers the targeted treatment of physical and psychosocial problems and also includes integrated palliation. Palliative care is a form of care that can be used in addition to curative therapies, and it is advisable and necessary to introduce it as early as possible among brain tumor patients due to the significant deterioration of the quality of life. Dealing with seriously ill patients on a daily basis is also an emotional burden for the professional staff, and carries the risk of burnout. The support of the staff and family members, as well as the issues of adequate communication, are also part of the scope of the supportive care approach.

Novel prognostic biomarker TBC1D1 is associated with immunotherapy resistance in gliomas

Background

Glioma, an aggressive brain tumor, poses a challenge in understanding the mechanisms of treatment resistance, despite promising results from immunotherapy.

Methods

We identified genes associated with immunotherapy resistance through an analysis of The Cancer Genome Atlas (TCGA), Chinese Glioma Genome Atlas (CGGA), and Gene Expression Omnibus (GEO) databases. Subsequently, qRT-PCR and western blot analyses were conducted to measure the mRNA and protein levels of TBC1 Domain Family Member 1 (TBC1D1), respectively. Additionally, Gene Set Enrichment Analysis (GSEA) was employed to reveal relevant signaling pathways, and the expression of TBC1D1 in immune cells was analyzed using single-cell RNA sequencing (scRNA-seq) data from GEO database. Tumor Immune Dysfunction and Exclusion (TIDE) database was utilized to assess T-cell function, while Tumor Immunotherapy Gene Expression Resource (TIGER) database was employed to evaluate immunotherapy resistance in relation to TBC1D1. Furthermore, the predictive performance of molecules on prognosis was assessed using Kaplan-Meier plots, nomograms, and ROC curves.

Results

The levels of TBC1D1 were significantly elevated in tumor tissue from glioma patients. Furthermore, high TBC1D1 expression was observed in macrophages compared to other cells, which negatively impacted T cell function, impaired immunotherapy response, promoted treatment tolerance, and led to poor prognosis. Inhibition of TBC1D1 was found to potentially synergistically enhance the efficacy of immunotherapy and prolong the survival of cancer patients with gliomas.

Conclusion

Heightened expression of TBC1D1 may facilitate an immunosuppressive microenvironment and predict a poor prognosis. Blocking TBC1D1 could minimize immunotherapy resistance in cancer patients with gliomas.

The use of sodium MRI in the diagnosis of an anaplastic astrocytoma during immunotherapy: a case report

Gliomas in the pediatric population are targeted with immune-modulating therapies. The gold standard imaging modality for diagnosis and monitoring treatment response is magnetic resonance imaging (MRI); however, the complex post-therapy-induced changes can make treatment response assessment difficult. These include radiation necrosis, pseudoresponse, and pseudoprogression, as well as more complex responses in the setting of immunotherapy. We report a case of an 11-year-old male with a supratentorial astrocytoma (WHO grade 3) that underwent treatment with immunotherapy. There was a clinical concern for progression due to increased fluid-attenuated inversion recovery (FLAIR) hyperintensity at the site of the primary neoplasm during immunotherapy. However, the Sodium (23Na) MRI continued demonstrating decreased total sodium concentrations, supporting pseudoprogression over true progression, which was confirmed clinicaly. This case reports the capability of 23Na MRI to differentiate between progression, recurrence, and other posttreatment changes.

Treatment outcome of IDH1/2 wildtype CNS WHO grade 4 glioma histologically diagnosed as WHO grade II or III astrocytomas

BACKGROUND

Isocitrate dehydrogenase (IDH)1/2 wildtype (wt) astrocytomas formerly classified as WHO grade II or III have significantly shorter PFS and OS than IDH mutated WHO grade 2 and 3 gliomas leading to a classification as CNS WHO grade 4. It is the aim of this study to evaluate differences in the treatment-related clinical course of these tumors as they are largely unknown.

METHODS

Patients undergoing surgery (between 2016-2019 in six neurosurgical departments) for a histologically diagnosed WHO grade 2-3 IDH1/2-wt astrocytoma were retrospectively reviewed to assess progression free survival (PFS), overall survival (OS), and prognostic factors.

RESULTS

This multi-center study included 157 patients (mean age 58 years (20-87 years); with 36.9% females). The predominant histology was anaplastic astrocytoma WHO grade 3 (78.3%), followed by diffuse astrocytoma WHO grade 2 (21.7%). Gross total resection (GTR) was achieved in 37.6%, subtotal resection (STR) in 28.7%, and biopsy was performed in 33.8%. The median PFS (12.5 months) and OS (27.0 months) did not differ between WHO grades. Both, GTR and STR significantly increased PFS (P < 0.01) and OS (P < 0.001) compared to biopsy. Treatment according to Stupp protocol was not associated with longer OS or PFS compared to chemotherapy or radiotherapy alone. EGFR amplification (P = 0.014) and TERT-promotor mutation (P = 0.042) were associated with shortened OS. MGMT-promoter methylation had no influence on treatment response.

CONCLUSIONS

WHO grade 2 and 3 IDH1/2 wt astrocytomas, treated according to the same treatment protocols, have a similar OS. Age, extent of resection, and strong EGFR expression were the most important treatment related prognostic factors.

Brain metastasis in a patient with BRCA2-mutated treatment-related neuroendocrine prostate carcinoma and long-term response to radiotherapy and Olaparib: A case report and literature review

BACKGROUND

A new subtype of prostate cancer called treatment-related neuroendocrine prostate carcinoma (t-NEPC) was added to the revised World Health Organization classification of prostate cancer in 2022. t-NEPC cases are increasing, and there is no established standard treatment.

METHODS

A 49-year-old male patient was referred to our department for dysuria. A rectal examination and a prostate biopsy revealed stony hardness and prostate adenocarcinoma, respectively. Imaging studies confirmed the presence of multiple bone and lymph node metastases. The patient was started on upfront treatment with androgen deprivation therapy and an androgen receptor signaling inhibitor, which resulted in a significant (>90%) decrease in prostate-specific antigen (PSA) levels. The patient experienced postrenal failure 6 months later, attributable to local disease progression. Concurrently, there was an elevation in neuron-specific enolase (NSE) levels and an enlargement of pelvic lymph node metastases, without PSA progression.

RESULTS

Biopsy specimen for cancer genome profiling revealed deletion of BRCA 2 and PTEN, AR amplification, and the presence of the TMPRSS2-ERG fusion gene. Based on increased NSE and BRCA2 mutations, a diagnosis of t-NEPC with BRCA2 mutation was eventually made. The patient received docetaxel chemotherapy and pelvic radiotherapy. Subsequently, he was treated with olaparib. His NSE levels decreased, and he achieved a complete response (CR). However, 18 months following the olaparib administration, brain metastases appeared despite the absence of pelvic tumor relapse, and the patient's PSA levels remained low. Consequently, the patient underwent resection of the brain metastases using gamma knife and whole-brain radiotherapy but died approximately 3 months later.

CONCLUSION SUBSECTIONS

Platinum-based chemotherapy is often administered for the treatment of t-NEPC, but there are few reports on the effectiveness of olaparib in patients with BRCA2 mutations. In a literature review, this case demonstrated the longest duration of effectiveness with olaparib alone without platinum-based chemotherapy. Additionally, the occurrence of relatively rare, fatal brain metastases in prostate cancer after a long period of CR suggests the necessity of regular brain imaging examinations.

Evolution of RANO in Assessing Brain Tumour Outcomes

Assessing treatment response is extremely important in management of brain tumours. Response assessment in neuro-oncology (RANO) was introduced in 2008 for the purpose of making recommendations for it by addressing and countering the limitations in previously reported response criteriae. Subsequently, multiple RANO working groups have been formed to cater to different tumour types and to update their previous recommendations to counter the limitations in their criteria. Herein we have a summarized list of RANO criteria for adult brain tumours.

Extracranial metastasis of pediatric glioblastoma: case report and literature review

Glioblastoma (GBM) is a rare primary brain tumor in children, and extracranial metastases of pediatric GBM are particularly uncommon. We present the case of a 10-year-old girl with pediatric GBM who developed multiple extracranial metastases, including cervical lymph nodes, spine, and lung. We discuss the rarity of extracranial metastases in GBM and explore possible mechanisms of dissemination. The patient underwent surgical resections, radiotherapy, and chemotherapy, but the metastatic disease progressed despite treatment. We emphasize the need to consider extracranial metastases in pediatric GBM patients and adopt multimodal treatment approaches for managing this rare clinical entity. As the survival rates of pediatric GBM patients are improving, awareness of extracranial metastases is crucial for optimizing treatment outcomes.

Post-treatment imaging of gliomas: challenging the existing dogmas

Gliomas are the commonest malignant central nervous system tumours in adults and imaging is the cornerstone of diagnosis, treatment, and post-treatment follow-up of these patients. With the ever-evolving treatment strategies post-treatment imaging and interpretation in glioma remains challenging, more so with the advent of anti-angiogenic drugs and immunotherapy, which can significantly alter the appearance in this setting, thus making interpretation of routine imaging findings such as contrast enhancement, oedema, and mass effect difficult to interpret. This review details the various methods of management of glioma including the upcoming novel therapies and their impact on imaging findings, with a comprehensive description of the imaging findings in conventional and advanced imaging techniques. A systematic appraisal for the existing and emerging techniques of imaging in these settings and their clinical application including various response assessment guidelines and artificial intelligence based response assessment will also be discussed.

Autologous cell immunotherapy (IGV-001) with IGF-1R antisense oligonucleotide in newly diagnosed glioblastoma patients

Standard-of-care first-line therapy for patients with newly diagnosed glioblastoma (ndGBM) is maximal safe surgical resection, then concurrent radiotherapy and temozolomide, followed by maintenance temozolomide. IGV-001, the first product of the Goldspire™ platform, is a first-in-class autologous immunotherapeutic product that combines personalized whole tumor-derived cells with an antisense oligonucleotide (IMV-001) in implantable biodiffusion chambers, with the intent to induce a tumor-specific immune response in patients with ndGBM. Here, we describe the design and rationale of a randomized, double-blind, phase IIb trial evaluating IGV-001 compared with placebo, both followed by standard-of-care treatment in patients with ndGBM. The primary end point is progression-free survival, and key secondary end points include overall survival and safety.

Palliative care for children with central nervous system tumors: results of a Spanish multicenter study

BACKGROUND

Brain tumors represent the most common cause of cancer-related death in children. Few studies concerning the palliative phase in children with brain tumors are available.

OBJECTIVES

(i) To describe the palliative phase in children with brain tumors; (ii) to determine whether the use of palliative sedation (PS) depends on the place of death, the age of the patient, or if they received specific palliative care (PC).

METHODS

Retrospective multicenter study between 2010 and 2021, including children from one month to 18 years, who had died of a brain tumor.

RESULTS

228 patients (59.2% male) from 10 Spanish institutions were included. Median age at diagnosis was 5 years (IQR 2-9) and median age at death was 7 years (IQR 4-11). The most frequent tumors were medulloblastoma (25.4%) and diffuse intrinsic pontine glioma (DIPG) (24.1%). Median number of antineoplastic regimens were 2 (range 0-5 regimens). During palliative phase, 52.2% of the patients were attended by PC teams, while 47.8% were cared exclusively by pediatric oncology teams. Most common concerns included motor deficit (93.4%) and asthenia (87.5%) and communication disorders (89.8%). Most frequently prescribed supportive drugs were antiemetics (83.6%), opioids (81.6%), and dexamethasone (78.5%). PS was administered to 48.7% patients. Most of them died in the hospital (85.6%), while patients who died at home required PS less frequently (14.4%) (p = .01).

CONCLUSION

Children dying from CNS tumors have specific needs during palliative phase. The optimal indication of PS depended on the center experience although, in our series, it was also influenced by the place of death.

Prognostic and predictive biomarkers in central nervous system tumours: the molecular state of play

Central nervous system (CNS) tumours were one of the first cancer types to adopt and integrate molecular profiling into routine clinical diagnosis in 2016. The vast majority of these biomarkers, used to discriminate between tumour types, also offered prognostic information. With the advent of The Cancer Genome Atlas (TCGA) and other large genomic datasets, further prognostic sub-stratification was possible within tumour types, leading to increased precision in CNS tumour grading. This review outlines the evolution of the molecular landscape of adult CNS tumours, through the prism of World Health Organization (WHO) Classifications. We begin our journey in the pre-molecular era, where high-grade gliomas were divided into 'primary' and 'secondary' glioblastomas. Molecular alterations explaining these clinicopathological observations were the first branching points of glioma diagnostics, with the discovery of IDH1/2 mutations and 1p/19q codeletion. Subsequently, the rigorous characterisation of paediatric gliomas led to the unearthing of histone H3 alterations as a key event in gliomagenesis, which also had implications for young adult patients. Simultaneously, studies investigating prognostic biomarkers within tumour types were undertaken. Certain genomic phenotypes were found to portend unfavourable outcomes, for example, MYCN amplification in spinal ependymoma. The arrival of methylation profiling, having revolutionised the diagnosis of CNS tumours, now promises to bring increased prognostic accuracy, as has been shown in meningiomas. While MGMT promoter hypermethylation has remained a reliable biomarker of response to cytotoxic chemotherapy, targeted therapy in CNS tumours has unfortunately not had the success of other cancers. Therefore, predictive biomarkers have lagged behind the identification of prognostic biomarkers in CNS tumours. Emerging research from new clinical trials is cause for guarded optimism and may shift our conceptualisation of predictive biomarker testing in CNS tumours.

Deep learning-based detection and quantification of brain metastases on black-blood imaging can provide treatment suggestions: a clinical cohort study

OBJECTIVES

We aimed to evaluate whether deep learning-based detection and quantification of brain metastasis (BM) may suggest treatment options for patients with BMs.

METHODS

The deep learning system (DLS) for detection and quantification of BM was developed in 193 patients and applied to 112 patients that were newly detected on black-blood contrast-enhanced T1-weighted imaging. Patients were assigned to one of 3 treatment suggestion groups according to the European Association of Neuro-Oncology (EANO)-European Society for Medical Oncology (ESMO) recommendations using number and volume of the BMs detected by the DLS: short-term imaging follow-up without treatment (group A), surgery or stereotactic radiosurgery (limited BM, group B), or whole-brain radiotherapy or systemic chemotherapy (extensive BM, group C). The concordance between the DLS-based groups and clinical decisions was analyzed with or without consideration of targeted agents. The performance of distinguishing high-risk (B + C) was calculated.

RESULTS

Among 112 patients (mean age 64.3 years, 63 men), group C had the largest number and volume of BM, followed by group B (4.4 and 851.6 mm3) and A (1.5 and 15.5 mm3). The DLS-based groups were concordant with the actual clinical decisions, with an accuracy of 76.8% (86 of 112). Modified accuracy considering targeted agents was 81.3% (91 of 112). The DLS showed 95% (82/86) sensitivity and 81% (21/26) specificity for distinguishing the high risk.

CONCLUSION

DLS-based detection and quantification of BM have the potential to be helpful in the determination of treatment options for both low- and high-risk groups of limited and extensive BMs.

CLINICAL RELEVANCE STATEMENT

For patients with newly diagnosed brain metastasis, deep learning-based detection and quantification may be used in clinical settings where prompt and accurate treatment decisions are required, which can lead to better patient outcomes.

KEY POINTS

• Deep learning-based brain metastasis detection and quantification showed excellent agreement with ground-truth classifications. • By setting an algorithm to suggest treatment based on the number and volume of brain metastases detected by the deep learning system, the concordance was 81.3%. • When dividing patients into low- and high-risk groups, the sensitivity for detecting the latter was 95%.

Local and Systemic Management Options for Melanoma Brain Metastases

ABSTRACT

Development of brain metastasis is one of the most serious complications of advanced melanoma, carrying a significant burden of morbidity and mortality. Although advances in local treatment modalities such as stereotactic radiosurgery and breakthrough systemic therapies including immunotherapy and targeted therapies have improved the outcomes of patients with metastatic melanoma, management of patients with melanoma brain metastases (MBMs) remains challenging. Notably, patients with MBMs have historically been excluded from clinical trials, limiting insights into their specific treatment responses. Encouragingly, a growing body of evidence shows the potential of systemic therapies to yield durable intracranial responses in these patients, highlighting the need for inclusion of patients with MBMs in future clinical trials. This is pivotal for expediting the advancement of novel therapies tailored to this distinct patient population. In this review, we will highlight the evolving landscape of MBM management, focusing on local and systemic treatment strategies.

Brain tumours: Non-invasive techniques to treat invasive pathologies

Brain and other central nervous system tumours are cancers of poor prognosis, for which current therapeutic possibilities do not match the expectations regarding a curative objective. If the treatment of central nervous system tumours is so difficult, it is partly due to the blood-brain barrier and the blood-tumour barrier, which need to be crossed to access the tumour. Driven by these insufficient results, more and more techniques and technologies are being explored and are evolving: the progress of surgery and radiotherapy, the growing place of immunotherapies, or the apparition of new non-invasive techniques. The latter are those which interest us here, where promising advances are taking the leap to clinical trials. Nose-to-brain delivery, receptor-mediated transcytosis and micro-bubbles-associated focused ultrasounds are three therapeutic propositions with encouraging results regarding the improvement of drug access to the brain. Even though they might have their share of limits and adverse effects, benefit-risk balance looks promising, and they may appear as new options to treat patients in the future.

Antitumor Effects of Intravenous Natural Killer Cell Infusion in an Orthotopic Glioblastoma Xenograft Murine Model and Gene Expression Profile Analysis

Despite standard multimodality treatment, containing maximum safety resection, temozolomide, radiotherapy, and a tumor-treating field, patients with glioblastoma (GBM) present with a dismal prognosis. Natural killer cell (NKC)-based immunotherapy would play a critical role in GBM treatment. We have previously reported highly activated and ex vivo expanded NK cells derived from human peripheral blood, which exhibited anti-tumor effect against GBM cells. Here, we performed preclinical evaluation of the NK cells using an in vivo orthotopic xenograft model, the U87MG cell-derived brain tumor in NOD/Shi-scid, IL-2RɤKO (NOG) mouse. In the orthotopic xenograft model, the retro-orbital venous injection of NK cells prolonged overall survival of the NOG mouse, indirectly indicating the growth-inhibition effect of NK cells. In addition, we comprehensively summarized the differentially expressed genes, especially focusing on the expression of the NKC-activating receptors' ligands, inhibitory receptors' ligands, chemokines, and chemokine receptors, between murine brain tumor treated with NKCs and with no agents, by using microarray. Furthermore, we also performed differentially expressed gene analysis between an internal and external brain tumor in the orthotopic xenograft model. Our findings could provide pivotal information for the NK-cell-based immunotherapy for patients with GBM.

Brain tumors in United States military veterans

BACKGROUND

Comprehensive analysis of brain tumor incidence and survival in the Veteran population has been lacking.

METHODS

Veteran data were obtained from the Veterans Health Administration (VHA) Medical Centers via VHA Corporate Data Warehouse. Brain tumor statistics on the overall US population were generated from the Central Brain Tumor Registry of the US data. Cases were individuals (≥18 years) with a primary brain tumor, diagnosed between 2004 and 2018. The average annual age-adjusted incidence rates (AAIR) and 95% confidence intervals were estimated per 100 000 population and Kaplan-Meier survival curves evaluated overall survival outcomes among Veterans.

RESULTS

The Veteran population was primarily white (78%), male (93%), and between 60 and 64 years old (18%). Individuals with a primary brain tumor in the general US population were mainly female (59%) and between 18 and 49 years old (28%). The overall AAIR of primary brain tumors from 2004 to 2018 within the Veterans Affairs cancer registry was 11.6. Nonmalignant tumors were more common than malignant tumors (AAIR:7.19 vs 4.42). The most diagnosed tumors in Veterans were nonmalignant pituitary tumors (AAIR:2.96), nonmalignant meningioma (AAIR:2.62), and glioblastoma (AAIR:1.96). In the Veteran population, survival outcomes became worse with age and were lowest among individuals diagnosed with glioblastoma.

CONCLUSIONS

Differences between Veteran and US populations can be broadly attributed to demographic composition differences of these groups. Prior to this, there have been no reports on national-level incidence rates and survival outcomes for Veterans. These data provide vital information that can drive efforts to understand disease burden and improve outcomes for individuals with primary brain tumors.

Preclinical pediatric brain tumor models for immunotherapy: Hurdles and a way forward

Brain tumors are the most common solid tumor in children and the leading cause of cancer-related deaths. Over the last few years, improvements have been made in the diagnosis and treatment of children with Central Nervous System tumors. Unfortunately, for many patients with high-grade tumors, the overall prognosis remains poor. Lower survival rates are partly attributed to the lack of efficacious therapies. The advent and success of immune checkpoint inhibitors (ICIs) in adults have sparked interest in investigating the utility of these therapies alone or in combination with other drug treatments in pediatric patients. However, to achieve improved clinical outcomes, the establishment and selection of relevant and robust preclinical pediatric high-grade brain tumor models is imperative. Here, we review the information that influenced our model selection as we embarked on an international collaborative study to test ICIs in combination with epigenetic modifying agents to enhance adaptive immunity to treat pediatric brain tumors. We also share challenges that we faced and potential solutions.

Lessons learned from phase 3 trials of immunotherapy for glioblastoma: Time for longitudinal sampling?

Glioblastoma (GBM)'s median overall survival is almost 21 months. Six phase 3 immunotherapy clinical trials have recently been published, yet 5/6 did not meet approval by regulatory bodies. For the sixth, approval is uncertain. Trial failures result from multiple factors, ranging from intrinsic tumor biology to clinical trial design. Understanding the clinical and basic science of these 6 trials is compelled by other immunotherapies reaching the point of advanced phase 3 clinical trial testing. We need to understand more of the science in human GBMs in early trials: the "window of opportunity" design may not be best to understand complex changes brought about by immunotherapeutic perturbations of the GBM microenvironment. The convergence of increased safety of image-guided biopsies with "multi-omics" of small cell numbers now permits longitudinal sampling of tumor and biofluids to dissect the complex temporal changes in the GBM microenvironment as a function of the immunotherapy.

Tumor-specific polycistronic miRNA delivered by engineered exosomes for the treatment of glioblastoma

BACKGROUND

Glioblastoma (GBM) has poor prognosis due to ineffective agents and poor delivery methods. MicroRNAs (miRs) have been explored as novel therapeutics for GBM, but the optimal miRs and the ideal delivery strategy remain unresolved. In this study, we sought to identify the most effective pan-subtype anti-GBM miRs and to develop an improved delivery system for these miRs.

METHODS

We conducted an unbiased screen of over 600 miRs against 7 glioma stem cell (GSC) lines representing all GBM subtypes to identify a set of pan-subtype-specific anti-GBM miRs and then used available TCGA GBM patient outcomes and miR expression data to hone in on miRs that were most likely to be clinically effective. To enhance delivery and expression of the miRs, we generated a polycistronic plasmid encoding 3 miRs (pPolymiR) and used HEK293T cells as biofactories to package pPolymiR into engineered exosomes (eExos) that incorporate viral proteins (Gag/VSVg) in their structure (eExos+pPolymiR) to enhance function.

RESULTS

Our stepwise screen identified miR-124-2, miR-135a-2, and let-7i as the most effective miRs across all GBM subtypes with clinical relevance. Delivery of eExos+pPolymiR resulted in high expression of all 3 miRs in GSCs, and significantly decreased GSC proliferation in vitro. eExos+pPolymiR prolonged survival of GSC-bearing mice in vivo when compared with eExos carrying each of the miRs individually or as a cocktail.

CONCLUSION

eExos+pPolymiR, which includes a pan-subtype anti-glioma-specific miR combination encoded in a polycistronic plasmid and a novel exosome delivery platform, represents a new and potentially powerful anti-GBM therapeutic.

Intratumoral Delivery of Chimeric Antigen Receptor T Cells Targeting CD133 Effectively Treats Brain Metastases

PURPOSE

Brain metastases (BM) are mainly treated palliatively with an expected survival of less than 12 months after diagnosis. In many solid tumors, the human neural stem cell marker glycoprotein CD133 is a marker of a tumor-initiating cell population that contributes to therapy resistance, relapse, and metastasis.

EXPERIMENTAL DESIGN

Here, we use a variant of our previously described CD133 binder to generate second-generation CD133-specific chimeric antigen receptor T cells (CAR-T) to demonstrate its specificity and efficacy against multiple patient-derived BM cell lines with variable CD133 antigen expression.

RESULTS

Using both lung- and colon-BM patient-derived xenograft models, we show that a CD133-targeting CAR-T cell therapy can evoke significant tumor reduction and survival advantage after a single dose, with complete remission observed in the colon-BM model.

CONCLUSIONS

In summary, these data suggest that CD133 plays a critical role in fueling the growth of BM, and immunotherapeutic targeting of this cell population is a feasible strategy to control the outgrowth of BM tumors that are otherwise limited to palliative care. See related commentary by Sloan et al., p. 477.

Theranostics in Neurooncology: Heading Toward New Horizons

Therapeutic approaches to brain tumors remain a challenge, with considerable limitations regarding delivery of drugs. There has been renewed and increasing interest in translating the popular theranostic approach well known from prostate and neuroendocrine cancer to neurooncology. Although far from perfect, some of these approaches show encouraging preliminary results, such as for meningioma and leptomeningeal spread of certain pediatric brain tumors. In brain metastases and gliomas, clinical results have failed to impress. Perspectives on these theranostic approaches regarding meningiomas, brain metastases, gliomas, and common pediatric brain tumors will be discussed. For each tumor entity, the general context, an overview of the literature, and future perspectives will be provided. Ongoing studies will be discussed in the supplemental materials. As most theranostic agents are unlikely to cross the blood-brain barrier, the delivery of these agents will be dependent on the successful development and clinical implementation of techniques enhancing permeability and retention. Moreover, the international community should strive toward sufficiently large and randomized studies to generate high-level evidence on theranostic approaches with radioligand therapies for central nervous system tumors.

Treatment modalities and survival outcomes in prostate cancer parenchymal brain metastasis

BACKGROUND

Prostate cancer (PCa) parenchymal brain metastases are uncommon and troubling observations in the course of the disease. Our study aims to evaluate the prevalence of brain metastases among PCa patients while reporting various therapeutic modalities, clinical features, and oncological outcomes.

METHODS

We retrospectively identified 34 patients with parenchymal brain metastasis out of 4575 patients using a prospectively maintained database that contains clinicopathologic characteristics of PCa patients between January 2012 and December 2021. Based on the three treatment modalities used, the patients were divided into three groups: stereotactic radiosurgery (SRS), whole brain radiotherapy (WBRT), and systemic therapy alone. The Kaplan-Meier curve was used to calculate overall survival [OS] probability and the Cox proportional hazards regression model was used to compare between groups.

RESULTS

At the time of brain metastasis diagnosis, the median age was 66 years, the median (interquartile range [IQR]) prostate-specific antigen (PSA) was 2.2 (0.1-26.6) ng/ml and the median (IQR) months from initial PCa diagnosis to brain metastasis development was 70.8 (27.6-100.9). The median (IQR) primary Gleason score was 8 (7-9) and over a median (IQR) follow-up time of 2.2 (1.2-16.5) months, 76.5% (n = 26) of the patients died. Thirteen (38.2%) patients had solitary lesion, whereas 21 (61.8%) had ≥2 lesions. The lesions were supratentorial in 19 (55.9%) patients, infratentorial in six (17.6%), and both sides in nine (26.5%). Among all 34 patients, 10 (29.4%) were treated with SRS, seven (20.6%) with WBRT, and 17 (50%) with systemic therapy alone. OS varied greatly between the three treatment modalities (log-rank test, p = 0.049). Those who were treated with SRS and WBRT had better OS compared with patients who were treated with systemic therapy alone (hazard ratio: 0.37, 95% confidence interval: 0.16-0.86, p = 0.022).

CONCLUSIONS

In our single-institutional study, we confirmed that PCa brain metastasis is associated with poor survival outcomes and more advanced metastatic disease. Furthermore, we found that SRS and WBRT for brain metastasis in patients with recurrent PCa appear to be associated with improved OS as compared with systemic therapy alone and are likely secondary to selection bias.

Evaluation of Pathway to Diagnosis of Pediatric Brain Tumors in Tamil Nadu, India

PURPOSE

Delayed diagnosis and poor awareness are significant barriers to the early intervention of pediatric brain tumors. This multicenter observational study aimed to evaluate the baseline routes and time to diagnosis for pediatric brain tumors in Tamil Nadu (TN), with the goal of promoting early diagnosis and timely referrals in the future.

METHODS

A standard proforma was used to retrospectively collect information on demographics, diagnosis, referral pathways, and symptoms of incident pediatric brain tumor cases between January 2018 and October 2020 across eight tertiary hospitals in TN. Dates of symptom onset, first presentation of health care, and diagnosis were used to calculate total diagnostic interval (TDI), patient interval (PI), and diagnostic interval (DI).

RESULTS

A total of 144 cases (mean age, 6.64 years; range, 0-15.1 years) were included in the analysis. Among those, 94% (135/144) were from city/district areas, 40% (55/144) were self-referred, and 90% (129/144) had one to three health care professional visits before diagnosis. Median TDI, PI, and DI were 3.5 (IQR, 1-9.3), 0.6 (IQR, 0.1-4.6), and 0.6 (IQR, 0-3.3) weeks, respectively. Low-grade gliomas had the longest median TDI (6.6 weeks), followed by medulloblastomas (4.6 weeks) and high-grade gliomas (3.3 weeks). Average number of symptoms recorded was 1.7 at symptom onset and 1.9 at diagnosis.

CONCLUSION

Although there are some similarities with data from the United Kingdom, many low-grade and optic pathway tumors were unaccounted for in our study. DIs were relatively short, which suggests that infrastructure may not be a problem in this cohort. Increased training and establishment of proper cancer registries, combined with proper referral pathways, could enhance early diagnosis for these children.